175 files changed, 5516 insertions, 4179 deletions

diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
deleted file mode 100644
index 9ee4b3059..000000000
--- a/crates/hir/src/code_model.rs
+++ /dev/null
@@ -1,2095 +0,0 @@
-//! FIXME: write short doc here
-use std::{iter, sync::Arc};
-
-use arrayvec::ArrayVec;
-use base_db::{CrateDisplayName, CrateId, Edition, FileId};
-use either::Either;
-use hir_def::{
-    adt::{ReprKind, StructKind, VariantData},
-    expr::{BindingAnnotation, LabelId, Pat, PatId},
-    import_map,
-    item_tree::ItemTreeNode,
-    lang_item::LangItemTarget,
-    path::ModPath,
-    per_ns::PerNs,
-    resolver::{HasResolver, Resolver},
-    src::HasSource as _,
-    type_ref::TypeRef,
-    AdtId, AssocContainerId, AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId,
-    DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule, ImplId, LifetimeParamId,
-    LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
-    TypeParamId, UnionId,
-};
-use hir_def::{find_path::PrefixKind, item_scope::ItemInNs, visibility::Visibility};
-use hir_expand::{
-    diagnostics::DiagnosticSink,
-    name::{name, AsName},
-    MacroDefId, MacroDefKind,
-};
-use hir_ty::{
-    autoderef,
-    display::{write_bounds_like_dyn_trait_with_prefix, HirDisplayError, HirFormatter},
-    method_resolution,
-    traits::{FnTrait, Solution, SolutionVariables},
-    AliasTy, BoundVar, CallableDefId, CallableSig, Canonical, DebruijnIndex, GenericPredicate,
-    InEnvironment, Mutability, Obligation, ProjectionPredicate, ProjectionTy, Scalar, Substs,
-    TraitEnvironment, Ty, TyDefId, TyVariableKind,
-};
-use rustc_hash::FxHashSet;
-use stdx::{format_to, impl_from};
-use syntax::{
-    ast::{self, AttrsOwner, NameOwner},
-    AstNode, SmolStr,
-};
-use tt::{Ident, Leaf, Literal, TokenTree};
-
-use crate::{
-    db::{DefDatabase, HirDatabase},
-    has_source::HasSource,
-    HirDisplay, InFile, Name,
-};
-
-/// hir::Crate describes a single crate. It's the main interface with which
-/// a crate's dependencies interact. Mostly, it should be just a proxy for the
-/// root module.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Crate {
-    pub(crate) id: CrateId,
-}
-
-#[derive(Debug)]
-pub struct CrateDependency {
-    pub krate: Crate,
-    pub name: Name,
-}
-
-impl Crate {
-    pub fn dependencies(self, db: &dyn HirDatabase) -> Vec<CrateDependency> {
-        db.crate_graph()[self.id]
-            .dependencies
-            .iter()
-            .map(|dep| {
-                let krate = Crate { id: dep.crate_id };
-                let name = dep.as_name();
-                CrateDependency { krate, name }
-            })
-            .collect()
-    }
-
-    // FIXME: add `transitive_reverse_dependencies`.
-    pub fn reverse_dependencies(self, db: &dyn HirDatabase) -> Vec<Crate> {
-        let crate_graph = db.crate_graph();
-        crate_graph
-            .iter()
-            .filter(|&krate| {
-                crate_graph[krate].dependencies.iter().any(|it| it.crate_id == self.id)
-            })
-            .map(|id| Crate { id })
-            .collect()
-    }
-
-    pub fn root_module(self, db: &dyn HirDatabase) -> Module {
-        let def_map = db.crate_def_map(self.id);
-        Module { id: def_map.module_id(def_map.root()) }
-    }
-
-    pub fn root_file(self, db: &dyn HirDatabase) -> FileId {
-        db.crate_graph()[self.id].root_file_id
-    }
-
-    pub fn edition(self, db: &dyn HirDatabase) -> Edition {
-        db.crate_graph()[self.id].edition
-    }
-
-    pub fn display_name(self, db: &dyn HirDatabase) -> Option<CrateDisplayName> {
-        db.crate_graph()[self.id].display_name.clone()
-    }
-
-    pub fn query_external_importables(
-        self,
-        db: &dyn DefDatabase,
-        query: import_map::Query,
-    ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
-        import_map::search_dependencies(db, self.into(), query).into_iter().map(|item| match item {
-            ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
-            ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
-        })
-    }
-
-    pub fn all(db: &dyn HirDatabase) -> Vec<Crate> {
-        db.crate_graph().iter().map(|id| Crate { id }).collect()
-    }
-
-    /// Try to get the root URL of the documentation of a crate.
-    pub fn get_html_root_url(self: &Crate, db: &dyn HirDatabase) -> Option<String> {
-        // Look for #![doc(html_root_url = "...")]
-        let attrs = db.attrs(AttrDefId::ModuleId(self.root_module(db).into()));
-        let doc_attr_q = attrs.by_key("doc");
-
-        if !doc_attr_q.exists() {
-            return None;
-        }
-
-        let doc_url = doc_attr_q.tt_values().map(|tt| {
-            let name = tt.token_trees.iter()
-                .skip_while(|tt| !matches!(tt, TokenTree::Leaf(Leaf::Ident(Ident{text: ref ident, ..})) if ident == "html_root_url"))
-                .skip(2)
-                .next();
-
-            match name {
-                Some(TokenTree::Leaf(Leaf::Literal(Literal{ref text, ..}))) => Some(text),
-                _ => None
-            }
-        }).flat_map(|t| t).next();
-
-        doc_url.map(|s| s.trim_matches('"').trim_end_matches('/').to_owned() + "/")
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Module {
-    pub(crate) id: ModuleId,
-}
-
-/// The defs which can be visible in the module.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum ModuleDef {
-    Module(Module),
-    Function(Function),
-    Adt(Adt),
-    // Can't be directly declared, but can be imported.
-    Variant(Variant),
-    Const(Const),
-    Static(Static),
-    Trait(Trait),
-    TypeAlias(TypeAlias),
-    BuiltinType(BuiltinType),
-}
-impl_from!(
-    Module,
-    Function,
-    Adt(Struct, Enum, Union),
-    Variant,
-    Const,
-    Static,
-    Trait,
-    TypeAlias,
-    BuiltinType
-    for ModuleDef
-);
-
-impl From<VariantDef> for ModuleDef {
-    fn from(var: VariantDef) -> Self {
-        match var {
-            VariantDef::Struct(t) => Adt::from(t).into(),
-            VariantDef::Union(t) => Adt::from(t).into(),
-            VariantDef::Variant(t) => t.into(),
-        }
-    }
-}
-
-impl ModuleDef {
-    pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
-        match self {
-            ModuleDef::Module(it) => it.parent(db),
-            ModuleDef::Function(it) => Some(it.module(db)),
-            ModuleDef::Adt(it) => Some(it.module(db)),
-            ModuleDef::Variant(it) => Some(it.module(db)),
-            ModuleDef::Const(it) => Some(it.module(db)),
-            ModuleDef::Static(it) => Some(it.module(db)),
-            ModuleDef::Trait(it) => Some(it.module(db)),
-            ModuleDef::TypeAlias(it) => Some(it.module(db)),
-            ModuleDef::BuiltinType(_) => None,
-        }
-    }
-
-    pub fn canonical_path(&self, db: &dyn HirDatabase) -> Option<String> {
-        let mut segments = Vec::new();
-        segments.push(self.name(db)?.to_string());
-        for m in self.module(db)?.path_to_root(db) {
-            segments.extend(m.name(db).map(|it| it.to_string()))
-        }
-        segments.reverse();
-        Some(segments.join("::"))
-    }
-
-    pub fn definition_visibility(&self, db: &dyn HirDatabase) -> Option<Visibility> {
-        let module = match self {
-            ModuleDef::Module(it) => it.parent(db)?,
-            ModuleDef::Function(it) => return Some(it.visibility(db)),
-            ModuleDef::Adt(it) => it.module(db),
-            ModuleDef::Variant(it) => {
-                let parent = it.parent_enum(db);
-                let module = it.module(db);
-                return module.visibility_of(db, &ModuleDef::Adt(Adt::Enum(parent)));
-            }
-            ModuleDef::Const(it) => return Some(it.visibility(db)),
-            ModuleDef::Static(it) => it.module(db),
-            ModuleDef::Trait(it) => it.module(db),
-            ModuleDef::TypeAlias(it) => return Some(it.visibility(db)),
-            ModuleDef::BuiltinType(_) => return None,
-        };
-
-        module.visibility_of(db, self)
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        match self {
-            ModuleDef::Adt(it) => Some(it.name(db)),
-            ModuleDef::Trait(it) => Some(it.name(db)),
-            ModuleDef::Function(it) => Some(it.name(db)),
-            ModuleDef::Variant(it) => Some(it.name(db)),
-            ModuleDef::TypeAlias(it) => Some(it.name(db)),
-            ModuleDef::Module(it) => it.name(db),
-            ModuleDef::Const(it) => it.name(db),
-            ModuleDef::Static(it) => it.name(db),
-
-            ModuleDef::BuiltinType(it) => Some(it.name()),
-        }
-    }
-
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
-        let id = match self {
-            ModuleDef::Adt(it) => match it {
-                Adt::Struct(it) => it.id.into(),
-                Adt::Enum(it) => it.id.into(),
-                Adt::Union(it) => it.id.into(),
-            },
-            ModuleDef::Trait(it) => it.id.into(),
-            ModuleDef::Function(it) => it.id.into(),
-            ModuleDef::TypeAlias(it) => it.id.into(),
-            ModuleDef::Module(it) => it.id.into(),
-            ModuleDef::Const(it) => it.id.into(),
-            ModuleDef::Static(it) => it.id.into(),
-            _ => return,
-        };
-
-        let module = match self.module(db) {
-            Some(it) => it,
-            None => return,
-        };
-
-        hir_ty::diagnostics::validate_module_item(db, module.id.krate(), id, sink)
-    }
-}
-
-impl Module {
-    /// Name of this module.
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        let def_map = self.id.def_map(db.upcast());
-        let parent = def_map[self.id.local_id].parent?;
-        def_map[parent].children.iter().find_map(|(name, module_id)| {
-            if *module_id == self.id.local_id {
-                Some(name.clone())
-            } else {
-                None
-            }
-        })
-    }
-
-    /// Returns the crate this module is part of.
-    pub fn krate(self) -> Crate {
-        Crate { id: self.id.krate() }
-    }
-
-    /// Topmost parent of this module. Every module has a `crate_root`, but some
-    /// might be missing `krate`. This can happen if a module's file is not included
-    /// in the module tree of any target in `Cargo.toml`.
-    pub fn crate_root(self, db: &dyn HirDatabase) -> Module {
-        let def_map = db.crate_def_map(self.id.krate());
-        Module { id: def_map.module_id(def_map.root()) }
-    }
-
-    /// Iterates over all child modules.
-    pub fn children(self, db: &dyn HirDatabase) -> impl Iterator<Item = Module> {
-        let def_map = self.id.def_map(db.upcast());
-        let children = def_map[self.id.local_id]
-            .children
-            .iter()
-            .map(|(_, module_id)| Module { id: def_map.module_id(*module_id) })
-            .collect::<Vec<_>>();
-        children.into_iter()
-    }
-
-    /// Finds a parent module.
-    pub fn parent(self, db: &dyn HirDatabase) -> Option<Module> {
-        // FIXME: handle block expressions as modules (their parent is in a different DefMap)
-        let def_map = self.id.def_map(db.upcast());
-        let parent_id = def_map[self.id.local_id].parent?;
-        Some(Module { id: def_map.module_id(parent_id) })
-    }
-
-    pub fn path_to_root(self, db: &dyn HirDatabase) -> Vec<Module> {
-        let mut res = vec![self];
-        let mut curr = self;
-        while let Some(next) = curr.parent(db) {
-            res.push(next);
-            curr = next
-        }
-        res
-    }
-
-    /// Returns a `ModuleScope`: a set of items, visible in this module.
-    pub fn scope(
-        self,
-        db: &dyn HirDatabase,
-        visible_from: Option<Module>,
-    ) -> Vec<(Name, ScopeDef)> {
-        self.id.def_map(db.upcast())[self.id.local_id]
-            .scope
-            .entries()
-            .filter_map(|(name, def)| {
-                if let Some(m) = visible_from {
-                    let filtered =
-                        def.filter_visibility(|vis| vis.is_visible_from(db.upcast(), m.id));
-                    if filtered.is_none() && !def.is_none() {
-                        None
-                    } else {
-                        Some((name, filtered))
-                    }
-                } else {
-                    Some((name, def))
-                }
-            })
-            .flat_map(|(name, def)| {
-                ScopeDef::all_items(def).into_iter().map(move |item| (name.clone(), item))
-            })
-            .collect()
-    }
-
-    pub fn visibility_of(self, db: &dyn HirDatabase, def: &ModuleDef) -> Option<Visibility> {
-        self.id.def_map(db.upcast())[self.id.local_id].scope.visibility_of(def.clone().into())
-    }
-
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
-        let _p = profile::span("Module::diagnostics").detail(|| {
-            format!("{:?}", self.name(db).map_or("<unknown>".into(), |name| name.to_string()))
-        });
-        let def_map = self.id.def_map(db.upcast());
-        def_map.add_diagnostics(db.upcast(), self.id.local_id, sink);
-        for decl in self.declarations(db) {
-            match decl {
-                crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
-                crate::ModuleDef::Module(m) => {
-                    // Only add diagnostics from inline modules
-                    if def_map[m.id.local_id].origin.is_inline() {
-                        m.diagnostics(db, sink)
-                    }
-                }
-                _ => {
-                    decl.diagnostics(db, sink);
-                }
-            }
-        }
-
-        for impl_def in self.impl_defs(db) {
-            for item in impl_def.items(db) {
-                if let AssocItem::Function(f) = item {
-                    f.diagnostics(db, sink);
-                }
-            }
-        }
-    }
-
-    pub fn declarations(self, db: &dyn HirDatabase) -> Vec<ModuleDef> {
-        let def_map = self.id.def_map(db.upcast());
-        def_map[self.id.local_id].scope.declarations().map(ModuleDef::from).collect()
-    }
-
-    pub fn impl_defs(self, db: &dyn HirDatabase) -> Vec<Impl> {
-        let def_map = self.id.def_map(db.upcast());
-        def_map[self.id.local_id].scope.impls().map(Impl::from).collect()
-    }
-
-    /// Finds a path that can be used to refer to the given item from within
-    /// this module, if possible.
-    pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
-        hir_def::find_path::find_path(db, item.into(), self.into())
-    }
-
-    /// Finds a path that can be used to refer to the given item from within
-    /// this module, if possible. This is used for returning import paths for use-statements.
-    pub fn find_use_path_prefixed(
-        self,
-        db: &dyn DefDatabase,
-        item: impl Into<ItemInNs>,
-        prefix_kind: PrefixKind,
-    ) -> Option<ModPath> {
-        hir_def::find_path::find_path_prefixed(db, item.into(), self.into(), prefix_kind)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Field {
-    pub(crate) parent: VariantDef,
-    pub(crate) id: LocalFieldId,
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub enum FieldSource {
-    Named(ast::RecordField),
-    Pos(ast::TupleField),
-}
-
-impl Field {
-    pub fn name(&self, db: &dyn HirDatabase) -> Name {
-        self.parent.variant_data(db).fields()[self.id].name.clone()
-    }
-
-    /// Returns the type as in the signature of the struct (i.e., with
-    /// placeholder types for type parameters). This is good for showing
-    /// signature help, but not so good to actually get the type of the field
-    /// when you actually have a variable of the struct.
-    pub fn signature_ty(&self, db: &dyn HirDatabase) -> Type {
-        let var_id = self.parent.into();
-        let generic_def_id: GenericDefId = match self.parent {
-            VariantDef::Struct(it) => it.id.into(),
-            VariantDef::Union(it) => it.id.into(),
-            VariantDef::Variant(it) => it.parent.id.into(),
-        };
-        let substs = Substs::type_params(db, generic_def_id);
-        let ty = db.field_types(var_id)[self.id].clone().subst(&substs);
-        Type::new(db, self.parent.module(db).id.krate(), var_id, ty)
-    }
-
-    pub fn parent_def(&self, _db: &dyn HirDatabase) -> VariantDef {
-        self.parent
-    }
-}
-
-impl HasVisibility for Field {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        let variant_data = self.parent.variant_data(db);
-        let visibility = &variant_data.fields()[self.id].visibility;
-        let parent_id: hir_def::VariantId = self.parent.into();
-        visibility.resolve(db.upcast(), &parent_id.resolver(db.upcast()))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Struct {
-    pub(crate) id: StructId,
-}
-
-impl Struct {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).container.module(db.upcast()) }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.struct_data(self.id).name.clone()
-    }
-
-    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
-        db.struct_data(self.id)
-            .variant_data
-            .fields()
-            .iter()
-            .map(|(id, _)| Field { parent: self.into(), id })
-            .collect()
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        Type::from_def(
-            db,
-            self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-            self.id,
-        )
-    }
-
-    pub fn repr(self, db: &dyn HirDatabase) -> Option<ReprKind> {
-        db.struct_data(self.id).repr.clone()
-    }
-
-    pub fn kind(self, db: &dyn HirDatabase) -> StructKind {
-        self.variant_data(db).kind()
-    }
-
-    fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
-        db.struct_data(self.id).variant_data.clone()
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Union {
-    pub(crate) id: UnionId,
-}
-
-impl Union {
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.union_data(self.id).name.clone()
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).container.module(db.upcast()) }
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        Type::from_def(
-            db,
-            self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-            self.id,
-        )
-    }
-
-    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
-        db.union_data(self.id)
-            .variant_data
-            .fields()
-            .iter()
-            .map(|(id, _)| Field { parent: self.into(), id })
-            .collect()
-    }
-
-    fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
-        db.union_data(self.id).variant_data.clone()
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Enum {
-    pub(crate) id: EnumId,
-}
-
-impl Enum {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).container.module(db.upcast()) }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.enum_data(self.id).name.clone()
-    }
-
-    pub fn variants(self, db: &dyn HirDatabase) -> Vec<Variant> {
-        db.enum_data(self.id).variants.iter().map(|(id, _)| Variant { parent: self, id }).collect()
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        Type::from_def(
-            db,
-            self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-            self.id,
-        )
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Variant {
-    pub(crate) parent: Enum,
-    pub(crate) id: LocalEnumVariantId,
-}
-
-impl Variant {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.parent.module(db)
-    }
-    pub fn parent_enum(self, _db: &dyn HirDatabase) -> Enum {
-        self.parent
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.enum_data(self.parent.id).variants[self.id].name.clone()
-    }
-
-    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
-        self.variant_data(db)
-            .fields()
-            .iter()
-            .map(|(id, _)| Field { parent: self.into(), id })
-            .collect()
-    }
-
-    pub fn kind(self, db: &dyn HirDatabase) -> StructKind {
-        self.variant_data(db).kind()
-    }
-
-    pub(crate) fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
-        db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
-    }
-}
-
-/// A Data Type
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum Adt {
-    Struct(Struct),
-    Union(Union),
-    Enum(Enum),
-}
-impl_from!(Struct, Union, Enum for Adt);
-
-impl Adt {
-    pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
-        let subst = db.generic_defaults(self.into());
-        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
-    }
-
-    /// Turns this ADT into a type. Any type parameters of the ADT will be
-    /// turned into unknown types, which is good for e.g. finding the most
-    /// general set of completions, but will not look very nice when printed.
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        let id = AdtId::from(self);
-        Type::from_def(db, id.module(db.upcast()).krate(), id)
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        match self {
-            Adt::Struct(s) => s.module(db),
-            Adt::Union(s) => s.module(db),
-            Adt::Enum(e) => e.module(db),
-        }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        match self {
-            Adt::Struct(s) => s.name(db),
-            Adt::Union(u) => u.name(db),
-            Adt::Enum(e) => e.name(db),
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum VariantDef {
-    Struct(Struct),
-    Union(Union),
-    Variant(Variant),
-}
-impl_from!(Struct, Union, Variant for VariantDef);
-
-impl VariantDef {
-    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
-        match self {
-            VariantDef::Struct(it) => it.fields(db),
-            VariantDef::Union(it) => it.fields(db),
-            VariantDef::Variant(it) => it.fields(db),
-        }
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        match self {
-            VariantDef::Struct(it) => it.module(db),
-            VariantDef::Union(it) => it.module(db),
-            VariantDef::Variant(it) => it.module(db),
-        }
-    }
-
-    pub fn name(&self, db: &dyn HirDatabase) -> Name {
-        match self {
-            VariantDef::Struct(s) => s.name(db),
-            VariantDef::Union(u) => u.name(db),
-            VariantDef::Variant(e) => e.name(db),
-        }
-    }
-
-    pub(crate) fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
-        match self {
-            VariantDef::Struct(it) => it.variant_data(db),
-            VariantDef::Union(it) => it.variant_data(db),
-            VariantDef::Variant(it) => it.variant_data(db),
-        }
-    }
-}
-
-/// The defs which have a body.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum DefWithBody {
-    Function(Function),
-    Static(Static),
-    Const(Const),
-}
-impl_from!(Function, Const, Static for DefWithBody);
-
-impl DefWithBody {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        match self {
-            DefWithBody::Const(c) => c.module(db),
-            DefWithBody::Function(f) => f.module(db),
-            DefWithBody::Static(s) => s.module(db),
-        }
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        match self {
-            DefWithBody::Function(f) => Some(f.name(db)),
-            DefWithBody::Static(s) => s.name(db),
-            DefWithBody::Const(c) => c.name(db),
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Function {
-    pub(crate) id: FunctionId,
-}
-
-impl Function {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.lookup(db.upcast()).module(db.upcast()).into()
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.function_data(self.id).name.clone()
-    }
-
-    /// Get this function's return type
-    pub fn ret_type(self, db: &dyn HirDatabase) -> Type {
-        let resolver = self.id.resolver(db.upcast());
-        let ret_type = &db.function_data(self.id).ret_type;
-        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
-        let environment = TraitEnvironment::lower(db, &resolver);
-        Type {
-            krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-            ty: InEnvironment { value: Ty::from_hir_ext(&ctx, ret_type).0, environment },
-        }
-    }
-
-    pub fn self_param(self, db: &dyn HirDatabase) -> Option<SelfParam> {
-        if !db.function_data(self.id).has_self_param {
-            return None;
-        }
-        Some(SelfParam { func: self.id })
-    }
-
-    pub fn assoc_fn_params(self, db: &dyn HirDatabase) -> Vec<Param> {
-        let resolver = self.id.resolver(db.upcast());
-        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
-        let environment = TraitEnvironment::lower(db, &resolver);
-        db.function_data(self.id)
-            .params
-            .iter()
-            .map(|type_ref| {
-                let ty = Type {
-                    krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-                    ty: InEnvironment {
-                        value: Ty::from_hir_ext(&ctx, type_ref).0,
-                        environment: environment.clone(),
-                    },
-                };
-                Param { ty }
-            })
-            .collect()
-    }
-    pub fn method_params(self, db: &dyn HirDatabase) -> Option<Vec<Param>> {
-        if self.self_param(db).is_none() {
-            return None;
-        }
-        let mut res = self.assoc_fn_params(db);
-        res.remove(0);
-        Some(res)
-    }
-
-    pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
-        db.function_data(self.id).is_unsafe
-    }
-
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
-        let krate = self.module(db).id.krate();
-        hir_def::diagnostics::validate_body(db.upcast(), self.id.into(), sink);
-        hir_ty::diagnostics::validate_module_item(db, krate, self.id.into(), sink);
-        hir_ty::diagnostics::validate_body(db, self.id.into(), sink);
-    }
-
-    /// Whether this function declaration has a definition.
-    ///
-    /// This is false in the case of required (not provided) trait methods.
-    pub fn has_body(self, db: &dyn HirDatabase) -> bool {
-        db.function_data(self.id).has_body
-    }
-
-    /// A textual representation of the HIR of this function for debugging purposes.
-    pub fn debug_hir(self, db: &dyn HirDatabase) -> String {
-        let body = db.body(self.id.into());
-
-        let mut result = String::new();
-        format_to!(result, "HIR expressions in the body of `{}`:\n", self.name(db));
-        for (id, expr) in body.exprs.iter() {
-            format_to!(result, "{:?}: {:?}\n", id, expr);
-        }
-
-        result
-    }
-}
-
-// Note: logically, this belongs to `hir_ty`, but we are not using it there yet.
-pub enum Access {
-    Shared,
-    Exclusive,
-    Owned,
-}
-
-impl From<Mutability> for Access {
-    fn from(mutability: Mutability) -> Access {
-        match mutability {
-            Mutability::Not => Access::Shared,
-            Mutability::Mut => Access::Exclusive,
-        }
-    }
-}
-
-#[derive(Debug)]
-pub struct Param {
-    ty: Type,
-}
-
-impl Param {
-    pub fn ty(&self) -> &Type {
-        &self.ty
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct SelfParam {
-    func: FunctionId,
-}
-
-impl SelfParam {
-    pub fn access(self, db: &dyn HirDatabase) -> Access {
-        let func_data = db.function_data(self.func);
-        func_data
-            .params
-            .first()
-            .map(|param| match *param {
-                TypeRef::Reference(.., mutability) => match mutability {
-                    hir_def::type_ref::Mutability::Shared => Access::Shared,
-                    hir_def::type_ref::Mutability::Mut => Access::Exclusive,
-                },
-                _ => Access::Owned,
-            })
-            .unwrap_or(Access::Owned)
-    }
-}
-
-impl HasVisibility for Function {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        let function_data = db.function_data(self.id);
-        let visibility = &function_data.visibility;
-        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Const {
-    pub(crate) id: ConstId,
-}
-
-impl Const {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        db.const_data(self.id).name.clone()
-    }
-}
-
-impl HasVisibility for Const {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        let function_data = db.const_data(self.id);
-        let visibility = &function_data.visibility;
-        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Static {
-    pub(crate) id: StaticId,
-}
-
-impl Static {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        db.static_data(self.id).name.clone()
-    }
-
-    pub fn is_mut(self, db: &dyn HirDatabase) -> bool {
-        db.static_data(self.id).mutable
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Trait {
-    pub(crate) id: TraitId,
-}
-
-impl Trait {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).container.module(db.upcast()) }
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.trait_data(self.id).name.clone()
-    }
-
-    pub fn items(self, db: &dyn HirDatabase) -> Vec<AssocItem> {
-        db.trait_data(self.id).items.iter().map(|(_name, it)| (*it).into()).collect()
-    }
-
-    pub fn is_auto(self, db: &dyn HirDatabase) -> bool {
-        db.trait_data(self.id).auto
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct TypeAlias {
-    pub(crate) id: TypeAliasId,
-}
-
-impl TypeAlias {
-    pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
-        let subst = db.generic_defaults(self.id.into());
-        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
-        Some(self.module(db).krate())
-    }
-
-    pub fn type_ref(self, db: &dyn HirDatabase) -> Option<TypeRef> {
-        db.type_alias_data(self.id).type_ref.clone()
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        Type::from_def(db, self.id.lookup(db.upcast()).module(db.upcast()).krate(), self.id)
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        db.type_alias_data(self.id).name.clone()
-    }
-}
-
-impl HasVisibility for TypeAlias {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        let function_data = db.type_alias_data(self.id);
-        let visibility = &function_data.visibility;
-        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct BuiltinType {
-    pub(crate) inner: hir_def::builtin_type::BuiltinType,
-}
-
-impl BuiltinType {
-    pub fn ty(self, db: &dyn HirDatabase, module: Module) -> Type {
-        let resolver = module.id.resolver(db.upcast());
-        Type::new_with_resolver(db, &resolver, Ty::builtin(self.inner))
-            .expect("crate not present in resolver")
-    }
-
-    pub fn name(self) -> Name {
-        self.inner.as_name()
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct MacroDef {
-    pub(crate) id: MacroDefId,
-}
-
-impl MacroDef {
-    /// FIXME: right now, this just returns the root module of the crate that
-    /// defines this macro. The reasons for this is that macros are expanded
-    /// early, in `hir_expand`, where modules simply do not exist yet.
-    pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
-        let krate = self.id.krate;
-        let def_map = db.crate_def_map(krate);
-        let module_id = def_map.root();
-        Some(Module { id: def_map.module_id(module_id) })
-    }
-
-    /// XXX: this parses the file
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        self.source(db)?.value.name().map(|it| it.as_name())
-    }
-
-    /// Indicate it is a proc-macro
-    pub fn is_proc_macro(&self) -> bool {
-        matches!(self.id.kind, MacroDefKind::ProcMacro(_))
-    }
-
-    /// Indicate it is a derive macro
-    pub fn is_derive_macro(&self) -> bool {
-        matches!(self.id.kind, MacroDefKind::ProcMacro(_) | MacroDefKind::BuiltInDerive(_))
-    }
-}
-
-/// Invariant: `inner.as_assoc_item(db).is_some()`
-/// We do not actively enforce this invariant.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub enum AssocItem {
-    Function(Function),
-    Const(Const),
-    TypeAlias(TypeAlias),
-}
-pub enum AssocItemContainer {
-    Trait(Trait),
-    Impl(Impl),
-}
-pub trait AsAssocItem {
-    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem>;
-}
-
-impl AsAssocItem for Function {
-    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
-        as_assoc_item(db, AssocItem::Function, self.id)
-    }
-}
-impl AsAssocItem for Const {
-    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
-        as_assoc_item(db, AssocItem::Const, self.id)
-    }
-}
-impl AsAssocItem for TypeAlias {
-    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
-        as_assoc_item(db, AssocItem::TypeAlias, self.id)
-    }
-}
-impl AsAssocItem for ModuleDef {
-    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
-        match self {
-            ModuleDef::Function(it) => it.as_assoc_item(db),
-            ModuleDef::Const(it) => it.as_assoc_item(db),
-            ModuleDef::TypeAlias(it) => it.as_assoc_item(db),
-            _ => None,
-        }
-    }
-}
-fn as_assoc_item<ID, DEF, CTOR, AST>(db: &dyn HirDatabase, ctor: CTOR, id: ID) -> Option<AssocItem>
-where
-    ID: Lookup<Data = AssocItemLoc<AST>>,
-    DEF: From<ID>,
-    CTOR: FnOnce(DEF) -> AssocItem,
-    AST: ItemTreeNode,
-{
-    match id.lookup(db.upcast()).container {
-        AssocContainerId::TraitId(_) | AssocContainerId::ImplId(_) => Some(ctor(DEF::from(id))),
-        AssocContainerId::ContainerId(_) => None,
-    }
-}
-
-impl AssocItem {
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        match self {
-            AssocItem::Function(it) => Some(it.name(db)),
-            AssocItem::Const(it) => it.name(db),
-            AssocItem::TypeAlias(it) => Some(it.name(db)),
-        }
-    }
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        match self {
-            AssocItem::Function(f) => f.module(db),
-            AssocItem::Const(c) => c.module(db),
-            AssocItem::TypeAlias(t) => t.module(db),
-        }
-    }
-    pub fn container(self, db: &dyn HirDatabase) -> AssocItemContainer {
-        let container = match self {
-            AssocItem::Function(it) => it.id.lookup(db.upcast()).container,
-            AssocItem::Const(it) => it.id.lookup(db.upcast()).container,
-            AssocItem::TypeAlias(it) => it.id.lookup(db.upcast()).container,
-        };
-        match container {
-            AssocContainerId::TraitId(id) => AssocItemContainer::Trait(id.into()),
-            AssocContainerId::ImplId(id) => AssocItemContainer::Impl(id.into()),
-            AssocContainerId::ContainerId(_) => panic!("invalid AssocItem"),
-        }
-    }
-
-    pub fn containing_trait(self, db: &dyn HirDatabase) -> Option<Trait> {
-        match self.container(db) {
-            AssocItemContainer::Trait(t) => Some(t),
-            _ => None,
-        }
-    }
-}
-
-impl HasVisibility for AssocItem {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        match self {
-            AssocItem::Function(f) => f.visibility(db),
-            AssocItem::Const(c) => c.visibility(db),
-            AssocItem::TypeAlias(t) => t.visibility(db),
-        }
-    }
-}
-
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-pub enum GenericDef {
-    Function(Function),
-    Adt(Adt),
-    Trait(Trait),
-    TypeAlias(TypeAlias),
-    Impl(Impl),
-    // enum variants cannot have generics themselves, but their parent enums
-    // can, and this makes some code easier to write
-    Variant(Variant),
-    // consts can have type parameters from their parents (i.e. associated consts of traits)
-    Const(Const),
-}
-impl_from!(
-    Function,
-    Adt(Struct, Enum, Union),
-    Trait,
-    TypeAlias,
-    Impl,
-    Variant,
-    Const
-    for GenericDef
-);
-
-impl GenericDef {
-    pub fn params(self, db: &dyn HirDatabase) -> Vec<GenericParam> {
-        let generics = db.generic_params(self.into());
-        let ty_params = generics
-            .types
-            .iter()
-            .map(|(local_id, _)| TypeParam { id: TypeParamId { parent: self.into(), local_id } })
-            .map(GenericParam::TypeParam);
-        let lt_params = generics
-            .lifetimes
-            .iter()
-            .map(|(local_id, _)| LifetimeParam {
-                id: LifetimeParamId { parent: self.into(), local_id },
-            })
-            .map(GenericParam::LifetimeParam);
-        let const_params = generics
-            .consts
-            .iter()
-            .map(|(local_id, _)| ConstParam { id: ConstParamId { parent: self.into(), local_id } })
-            .map(GenericParam::ConstParam);
-        ty_params.chain(lt_params).chain(const_params).collect()
-    }
-
-    pub fn type_params(self, db: &dyn HirDatabase) -> Vec<TypeParam> {
-        let generics = db.generic_params(self.into());
-        generics
-            .types
-            .iter()
-            .map(|(local_id, _)| TypeParam { id: TypeParamId { parent: self.into(), local_id } })
-            .collect()
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct Local {
-    pub(crate) parent: DefWithBodyId,
-    pub(crate) pat_id: PatId,
-}
-
-impl Local {
-    pub fn is_param(self, db: &dyn HirDatabase) -> bool {
-        let src = self.source(db);
-        match src.value {
-            Either::Left(bind_pat) => {
-                bind_pat.syntax().ancestors().any(|it| ast::Param::can_cast(it.kind()))
-            }
-            Either::Right(_self_param) => true,
-        }
-    }
-
-    // FIXME: why is this an option? It shouldn't be?
-    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        let body = db.body(self.parent.into());
-        match &body[self.pat_id] {
-            Pat::Bind { name, .. } => Some(name.clone()),
-            _ => None,
-        }
-    }
-
-    pub fn is_self(self, db: &dyn HirDatabase) -> bool {
-        self.name(db) == Some(name![self])
-    }
-
-    pub fn is_mut(self, db: &dyn HirDatabase) -> bool {
-        let body = db.body(self.parent.into());
-        match &body[self.pat_id] {
-            Pat::Bind { mode, .. } => match mode {
-                BindingAnnotation::Mutable | BindingAnnotation::RefMut => true,
-                _ => false,
-            },
-            _ => false,
-        }
-    }
-
-    pub fn parent(self, _db: &dyn HirDatabase) -> DefWithBody {
-        self.parent.into()
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.parent(db).module(db)
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        let def = DefWithBodyId::from(self.parent);
-        let infer = db.infer(def);
-        let ty = infer[self.pat_id].clone();
-        let krate = def.module(db.upcast()).krate();
-        Type::new(db, krate, def, ty)
-    }
-
-    pub fn source(self, db: &dyn HirDatabase) -> InFile<Either<ast::IdentPat, ast::SelfParam>> {
-        let (_body, source_map) = db.body_with_source_map(self.parent.into());
-        let src = source_map.pat_syntax(self.pat_id).unwrap(); // Hmm...
-        let root = src.file_syntax(db.upcast());
-        src.map(|ast| {
-            ast.map_left(|it| it.cast().unwrap().to_node(&root)).map_right(|it| it.to_node(&root))
-        })
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct Label {
-    pub(crate) parent: DefWithBodyId,
-    pub(crate) label_id: LabelId,
-}
-
-impl Label {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.parent(db).module(db)
-    }
-
-    pub fn parent(self, _db: &dyn HirDatabase) -> DefWithBody {
-        self.parent.into()
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        let body = db.body(self.parent.into());
-        body[self.label_id].name.clone()
-    }
-
-    pub fn source(self, db: &dyn HirDatabase) -> InFile<ast::Label> {
-        let (_body, source_map) = db.body_with_source_map(self.parent.into());
-        let src = source_map.label_syntax(self.label_id);
-        let root = src.file_syntax(db.upcast());
-        src.map(|ast| ast.to_node(&root))
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum GenericParam {
-    TypeParam(TypeParam),
-    LifetimeParam(LifetimeParam),
-    ConstParam(ConstParam),
-}
-impl_from!(TypeParam, LifetimeParam, ConstParam for GenericParam);
-
-impl GenericParam {
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        match self {
-            GenericParam::TypeParam(it) => it.module(db),
-            GenericParam::LifetimeParam(it) => it.module(db),
-            GenericParam::ConstParam(it) => it.module(db),
-        }
-    }
-
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        match self {
-            GenericParam::TypeParam(it) => it.name(db),
-            GenericParam::LifetimeParam(it) => it.name(db),
-            GenericParam::ConstParam(it) => it.name(db),
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct TypeParam {
-    pub(crate) id: TypeParamId,
-}
-
-impl TypeParam {
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        let params = db.generic_params(self.id.parent);
-        params.types[self.id.local_id].name.clone().unwrap_or_else(Name::missing)
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.parent.module(db.upcast()).into()
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        let resolver = self.id.parent.resolver(db.upcast());
-        let environment = TraitEnvironment::lower(db, &resolver);
-        let ty = Ty::Placeholder(self.id);
-        Type {
-            krate: self.id.parent.module(db.upcast()).krate(),
-            ty: InEnvironment { value: ty, environment },
-        }
-    }
-
-    pub fn trait_bounds(self, db: &dyn HirDatabase) -> Vec<Trait> {
-        db.generic_predicates_for_param(self.id)
-            .into_iter()
-            .filter_map(|pred| match &pred.value {
-                hir_ty::GenericPredicate::Implemented(trait_ref) => {
-                    Some(Trait::from(trait_ref.trait_))
-                }
-                _ => None,
-            })
-            .collect()
-    }
-
-    pub fn default(self, db: &dyn HirDatabase) -> Option<Type> {
-        let params = db.generic_defaults(self.id.parent);
-        let local_idx = hir_ty::param_idx(db, self.id)?;
-        let resolver = self.id.parent.resolver(db.upcast());
-        let environment = TraitEnvironment::lower(db, &resolver);
-        let ty = params.get(local_idx)?.clone();
-        let subst = Substs::type_params(db, self.id.parent);
-        let ty = ty.subst(&subst.prefix(local_idx));
-        Some(Type {
-            krate: self.id.parent.module(db.upcast()).krate(),
-            ty: InEnvironment { value: ty, environment },
-        })
-    }
-}
-
-impl HirDisplay for TypeParam {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        write!(f, "{}", self.name(f.db))?;
-        let bounds = f.db.generic_predicates_for_param(self.id);
-        let substs = Substs::type_params(f.db, self.id.parent);
-        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
-        if !(predicates.is_empty() || f.omit_verbose_types()) {
-            write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;
-        }
-        Ok(())
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct LifetimeParam {
-    pub(crate) id: LifetimeParamId,
-}
-
-impl LifetimeParam {
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        let params = db.generic_params(self.id.parent);
-        params.lifetimes[self.id.local_id].name.clone()
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.parent.module(db.upcast()).into()
-    }
-
-    pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
-        self.id.parent.into()
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct ConstParam {
-    pub(crate) id: ConstParamId,
-}
-
-impl ConstParam {
-    pub fn name(self, db: &dyn HirDatabase) -> Name {
-        let params = db.generic_params(self.id.parent);
-        params.consts[self.id.local_id].name.clone()
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.parent.module(db.upcast()).into()
-    }
-
-    pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
-        self.id.parent.into()
-    }
-
-    pub fn ty(self, db: &dyn HirDatabase) -> Type {
-        let def = self.id.parent;
-        let krate = def.module(db.upcast()).krate();
-        Type::new(db, krate, def, db.const_param_ty(self.id))
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Impl {
-    pub(crate) id: ImplId,
-}
-
-impl Impl {
-    pub fn all_in_crate(db: &dyn HirDatabase, krate: Crate) -> Vec<Impl> {
-        let inherent = db.inherent_impls_in_crate(krate.id);
-        let trait_ = db.trait_impls_in_crate(krate.id);
-
-        inherent.all_impls().chain(trait_.all_impls()).map(Self::from).collect()
-    }
-    pub fn for_trait(db: &dyn HirDatabase, krate: Crate, trait_: Trait) -> Vec<Impl> {
-        let impls = db.trait_impls_in_crate(krate.id);
-        impls.for_trait(trait_.id).map(Self::from).collect()
-    }
-
-    // FIXME: the return type is wrong. This should be a hir version of
-    // `TraitRef` (ie, resolved `TypeRef`).
-    pub fn target_trait(self, db: &dyn HirDatabase) -> Option<TypeRef> {
-        db.impl_data(self.id).target_trait.clone()
-    }
-
-    pub fn target_ty(self, db: &dyn HirDatabase) -> Type {
-        let impl_data = db.impl_data(self.id);
-        let resolver = self.id.resolver(db.upcast());
-        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
-        let environment = TraitEnvironment::lower(db, &resolver);
-        let ty = Ty::from_hir(&ctx, &impl_data.target_type);
-        Type {
-            krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate(),
-            ty: InEnvironment { value: ty, environment },
-        }
-    }
-
-    pub fn items(self, db: &dyn HirDatabase) -> Vec<AssocItem> {
-        db.impl_data(self.id).items.iter().map(|it| (*it).into()).collect()
-    }
-
-    pub fn is_negative(self, db: &dyn HirDatabase) -> bool {
-        db.impl_data(self.id).is_negative
-    }
-
-    pub fn module(self, db: &dyn HirDatabase) -> Module {
-        self.id.lookup(db.upcast()).container.module(db.upcast()).into()
-    }
-
-    pub fn krate(self, db: &dyn HirDatabase) -> Crate {
-        Crate { id: self.module(db).id.krate() }
-    }
-
-    pub fn is_builtin_derive(self, db: &dyn HirDatabase) -> Option<InFile<ast::Attr>> {
-        let src = self.source(db)?;
-        let item = src.file_id.is_builtin_derive(db.upcast())?;
-        let hygenic = hir_expand::hygiene::Hygiene::new(db.upcast(), item.file_id);
-
-        // FIXME: handle `cfg_attr`
-        let attr = item
-            .value
-            .attrs()
-            .filter_map(|it| {
-                let path = ModPath::from_src(it.path()?, &hygenic)?;
-                if path.as_ident()?.to_string() == "derive" {
-                    Some(it)
-                } else {
-                    None
-                }
-            })
-            .last()?;
-
-        Some(item.with_value(attr))
-    }
-}
-
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub struct Type {
-    krate: CrateId,
-    ty: InEnvironment<Ty>,
-}
-
-impl Type {
-    pub(crate) fn new_with_resolver(
-        db: &dyn HirDatabase,
-        resolver: &Resolver,
-        ty: Ty,
-    ) -> Option<Type> {
-        let krate = resolver.krate()?;
-        Some(Type::new_with_resolver_inner(db, krate, resolver, ty))
-    }
-    pub(crate) fn new_with_resolver_inner(
-        db: &dyn HirDatabase,
-        krate: CrateId,
-        resolver: &Resolver,
-        ty: Ty,
-    ) -> Type {
-        let environment = TraitEnvironment::lower(db, &resolver);
-        Type { krate, ty: InEnvironment { value: ty, environment } }
-    }
-
-    fn new(db: &dyn HirDatabase, krate: CrateId, lexical_env: impl HasResolver, ty: Ty) -> Type {
-        let resolver = lexical_env.resolver(db.upcast());
-        let environment = TraitEnvironment::lower(db, &resolver);
-        Type { krate, ty: InEnvironment { value: ty, environment } }
-    }
-
-    fn from_def(
-        db: &dyn HirDatabase,
-        krate: CrateId,
-        def: impl HasResolver + Into<TyDefId> + Into<GenericDefId>,
-    ) -> Type {
-        let substs = Substs::build_for_def(db, def).fill_with_unknown().build();
-        let ty = db.ty(def.into()).subst(&substs);
-        Type::new(db, krate, def, ty)
-    }
-
-    pub fn is_unit(&self) -> bool {
-        matches!(self.ty.value, Ty::Tuple(0, ..))
-    }
-    pub fn is_bool(&self) -> bool {
-        matches!(self.ty.value, Ty::Scalar(Scalar::Bool))
-    }
-
-    pub fn is_mutable_reference(&self) -> bool {
-        matches!(self.ty.value, Ty::Ref(Mutability::Mut, ..))
-    }
-
-    pub fn remove_ref(&self) -> Option<Type> {
-        if let Ty::Ref(.., substs) = &self.ty.value {
-            Some(self.derived(substs[0].clone()))
-        } else {
-            None
-        }
-    }
-
-    pub fn is_unknown(&self) -> bool {
-        matches!(self.ty.value, Ty::Unknown)
-    }
-
-    /// Checks that particular type `ty` implements `std::future::Future`.
-    /// This function is used in `.await` syntax completion.
-    pub fn impls_future(&self, db: &dyn HirDatabase) -> bool {
-        // No special case for the type of async block, since Chalk can figure it out.
-
-        let krate = self.krate;
-
-        let std_future_trait =
-            db.lang_item(krate, "future_trait".into()).and_then(|it| it.as_trait());
-        let std_future_trait = match std_future_trait {
-            Some(it) => it,
-            None => return false,
-        };
-
-        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
-        method_resolution::implements_trait(
-            &canonical_ty,
-            db,
-            self.ty.environment.clone(),
-            krate,
-            std_future_trait,
-        )
-    }
-
-    /// Checks that particular type `ty` implements `std::ops::FnOnce`.
-    ///
-    /// This function can be used to check if a particular type is callable, since FnOnce is a
-    /// supertrait of Fn and FnMut, so all callable types implements at least FnOnce.
-    pub fn impls_fnonce(&self, db: &dyn HirDatabase) -> bool {
-        let krate = self.krate;
-
-        let fnonce_trait = match FnTrait::FnOnce.get_id(db, krate) {
-            Some(it) => it,
-            None => return false,
-        };
-
-        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
-        method_resolution::implements_trait_unique(
-            &canonical_ty,
-            db,
-            self.ty.environment.clone(),
-            krate,
-            fnonce_trait,
-        )
-    }
-
-    pub fn impls_trait(&self, db: &dyn HirDatabase, trait_: Trait, args: &[Type]) -> bool {
-        let trait_ref = hir_ty::TraitRef {
-            trait_: trait_.id,
-            substs: Substs::build_for_def(db, trait_.id)
-                .push(self.ty.value.clone())
-                .fill(args.iter().map(|t| t.ty.value.clone()))
-                .build(),
-        };
-
-        let goal = Canonical {
-            value: hir_ty::InEnvironment::new(
-                self.ty.environment.clone(),
-                hir_ty::Obligation::Trait(trait_ref),
-            ),
-            kinds: Arc::new([]),
-        };
-
-        db.trait_solve(self.krate, goal).is_some()
-    }
-
-    pub fn normalize_trait_assoc_type(
-        &self,
-        db: &dyn HirDatabase,
-        trait_: Trait,
-        args: &[Type],
-        alias: TypeAlias,
-    ) -> Option<Type> {
-        let subst = Substs::build_for_def(db, trait_.id)
-            .push(self.ty.value.clone())
-            .fill(args.iter().map(|t| t.ty.value.clone()))
-            .build();
-        let predicate = ProjectionPredicate {
-            projection_ty: ProjectionTy { associated_ty: alias.id, parameters: subst },
-            ty: Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)),
-        };
-        let goal = Canonical {
-            value: InEnvironment::new(
-                self.ty.environment.clone(),
-                Obligation::Projection(predicate),
-            ),
-            kinds: Arc::new([TyVariableKind::General]),
-        };
-
-        match db.trait_solve(self.krate, goal)? {
-            Solution::Unique(SolutionVariables(subst)) => subst.value.first().cloned(),
-            Solution::Ambig(_) => None,
-        }
-        .map(|ty| Type {
-            krate: self.krate,
-            ty: InEnvironment { value: ty, environment: Arc::clone(&self.ty.environment) },
-        })
-    }
-
-    pub fn is_copy(&self, db: &dyn HirDatabase) -> bool {
-        let lang_item = db.lang_item(self.krate, SmolStr::new("copy"));
-        let copy_trait = match lang_item {
-            Some(LangItemTarget::TraitId(it)) => it,
-            _ => return false,
-        };
-        self.impls_trait(db, copy_trait.into(), &[])
-    }
-
-    pub fn as_callable(&self, db: &dyn HirDatabase) -> Option<Callable> {
-        let def = match self.ty.value {
-            Ty::FnDef(def, _) => Some(def),
-            _ => None,
-        };
-
-        let sig = self.ty.value.callable_sig(db)?;
-        Some(Callable { ty: self.clone(), sig, def, is_bound_method: false })
-    }
-
-    pub fn is_closure(&self) -> bool {
-        matches!(&self.ty.value, Ty::Closure { .. })
-    }
-
-    pub fn is_fn(&self) -> bool {
-        matches!(&self.ty.value, Ty::FnDef(..) | Ty::Function { .. })
-    }
-
-    pub fn is_packed(&self, db: &dyn HirDatabase) -> bool {
-        let adt_id = match self.ty.value {
-            Ty::Adt(hir_ty::AdtId(adt_id), ..) => adt_id,
-            _ => return false,
-        };
-
-        let adt = adt_id.into();
-        match adt {
-            Adt::Struct(s) => matches!(s.repr(db), Some(ReprKind::Packed)),
-            _ => false,
-        }
-    }
-
-    pub fn is_raw_ptr(&self) -> bool {
-        matches!(&self.ty.value, Ty::Raw(..))
-    }
-
-    pub fn contains_unknown(&self) -> bool {
-        return go(&self.ty.value);
-
-        fn go(ty: &Ty) -> bool {
-            match ty {
-                Ty::Unknown => true,
-                _ => ty.substs().map_or(false, |substs| substs.iter().any(go)),
-            }
-        }
-    }
-
-    pub fn fields(&self, db: &dyn HirDatabase) -> Vec<(Field, Type)> {
-        let (variant_id, substs) = match self.ty.value {
-            Ty::Adt(hir_ty::AdtId(AdtId::StructId(s)), ref substs) => (s.into(), substs),
-            Ty::Adt(hir_ty::AdtId(AdtId::UnionId(u)), ref substs) => (u.into(), substs),
-            _ => return Vec::new(),
-        };
-
-        db.field_types(variant_id)
-            .iter()
-            .map(|(local_id, ty)| {
-                let def = Field { parent: variant_id.into(), id: local_id };
-                let ty = ty.clone().subst(substs);
-                (def, self.derived(ty))
-            })
-            .collect()
-    }
-
-    pub fn tuple_fields(&self, _db: &dyn HirDatabase) -> Vec<Type> {
-        if let Ty::Tuple(_, substs) = &self.ty.value {
-            substs.iter().map(|ty| self.derived(ty.clone())).collect()
-        } else {
-            Vec::new()
-        }
-    }
-
-    pub fn autoderef<'a>(&'a self, db: &'a dyn HirDatabase) -> impl Iterator<Item = Type> + 'a {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
-        let environment = self.ty.environment.clone();
-        let ty = InEnvironment { value: canonical, environment };
-        autoderef(db, Some(self.krate), ty)
-            .map(|canonical| canonical.value)
-            .map(move |ty| self.derived(ty))
-    }
-
-    // This would be nicer if it just returned an iterator, but that runs into
-    // lifetime problems, because we need to borrow temp `CrateImplDefs`.
-    pub fn iterate_assoc_items<T>(
-        self,
-        db: &dyn HirDatabase,
-        krate: Crate,
-        mut callback: impl FnMut(AssocItem) -> Option<T>,
-    ) -> Option<T> {
-        for krate in self.ty.value.def_crates(db, krate.id)? {
-            let impls = db.inherent_impls_in_crate(krate);
-
-            for impl_def in impls.for_self_ty(&self.ty.value) {
-                for &item in db.impl_data(*impl_def).items.iter() {
-                    if let Some(result) = callback(item.into()) {
-                        return Some(result);
-                    }
-                }
-            }
-        }
-        None
-    }
-
-    pub fn type_parameters(&self) -> impl Iterator<Item = Type> + '_ {
-        self.ty
-            .value
-            .strip_references()
-            .substs()
-            .into_iter()
-            .flat_map(|substs| substs.iter())
-            .map(move |ty| self.derived(ty.clone()))
-    }
-
-    pub fn iterate_method_candidates<T>(
-        &self,
-        db: &dyn HirDatabase,
-        krate: Crate,
-        traits_in_scope: &FxHashSet<TraitId>,
-        name: Option<&Name>,
-        mut callback: impl FnMut(&Ty, Function) -> Option<T>,
-    ) -> Option<T> {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
-
-        let env = self.ty.environment.clone();
-        let krate = krate.id;
-
-        method_resolution::iterate_method_candidates(
-            &canonical,
-            db,
-            env,
-            krate,
-            traits_in_scope,
-            name,
-            method_resolution::LookupMode::MethodCall,
-            |ty, it| match it {
-                AssocItemId::FunctionId(f) => callback(ty, f.into()),
-                _ => None,
-            },
-        )
-    }
-
-    pub fn iterate_path_candidates<T>(
-        &self,
-        db: &dyn HirDatabase,
-        krate: Crate,
-        traits_in_scope: &FxHashSet<TraitId>,
-        name: Option<&Name>,
-        mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
-    ) -> Option<T> {
-        // There should be no inference vars in types passed here
-        // FIXME check that?
-        // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
-
-        let env = self.ty.environment.clone();
-        let krate = krate.id;
-
-        method_resolution::iterate_method_candidates(
-            &canonical,
-            db,
-            env,
-            krate,
-            traits_in_scope,
-            name,
-            method_resolution::LookupMode::Path,
-            |ty, it| callback(ty, it.into()),
-        )
-    }
-
-    pub fn as_adt(&self) -> Option<Adt> {
-        let (adt, _subst) = self.ty.value.as_adt()?;
-        Some(adt.into())
-    }
-
-    pub fn as_dyn_trait(&self) -> Option<Trait> {
-        self.ty.value.dyn_trait().map(Into::into)
-    }
-
-    pub fn as_impl_traits(&self, db: &dyn HirDatabase) -> Option<Vec<Trait>> {
-        self.ty.value.impl_trait_bounds(db).map(|it| {
-            it.into_iter()
-                .filter_map(|pred| match pred {
-                    hir_ty::GenericPredicate::Implemented(trait_ref) => {
-                        Some(Trait::from(trait_ref.trait_))
-                    }
-                    _ => None,
-                })
-                .collect()
-        })
-    }
-
-    pub fn as_associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<Trait> {
-        self.ty.value.associated_type_parent_trait(db).map(Into::into)
-    }
-
-    // FIXME: provide required accessors such that it becomes implementable from outside.
-    pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
-        let rref = other.remove_ref();
-        self.ty.value.equals_ctor(rref.as_ref().map_or(&other.ty.value, |it| &it.ty.value))
-    }
-
-    fn derived(&self, ty: Ty) -> Type {
-        Type {
-            krate: self.krate,
-            ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
-        }
-    }
-
-    pub fn walk(&self, db: &dyn HirDatabase, mut cb: impl FnMut(Type)) {
-        // TypeWalk::walk for a Ty at first visits parameters and only after that the Ty itself.
-        // We need a different order here.
-
-        fn walk_substs(
-            db: &dyn HirDatabase,
-            type_: &Type,
-            substs: &Substs,
-            cb: &mut impl FnMut(Type),
-        ) {
-            for ty in substs.iter() {
-                walk_type(db, &type_.derived(ty.clone()), cb);
-            }
-        }
-
-        fn walk_bounds(
-            db: &dyn HirDatabase,
-            type_: &Type,
-            bounds: &[GenericPredicate],
-            cb: &mut impl FnMut(Type),
-        ) {
-            for pred in bounds {
-                match pred {
-                    GenericPredicate::Implemented(trait_ref) => {
-                        cb(type_.clone());
-                        walk_substs(db, type_, &trait_ref.substs, cb);
-                    }
-                    _ => (),
-                }
-            }
-        }
-
-        fn walk_type(db: &dyn HirDatabase, type_: &Type, cb: &mut impl FnMut(Type)) {
-            let ty = type_.ty.value.strip_references();
-            match ty {
-                Ty::Adt(..) => {
-                    cb(type_.derived(ty.clone()));
-                }
-                Ty::AssociatedType(..) => {
-                    if let Some(_) = ty.associated_type_parent_trait(db) {
-                        cb(type_.derived(ty.clone()));
-                    }
-                }
-                Ty::OpaqueType(..) => {
-                    if let Some(bounds) = ty.impl_trait_bounds(db) {
-                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
-                    }
-                }
-                Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
-                    if let Some(bounds) = ty.impl_trait_bounds(db) {
-                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
-                    }
-
-                    walk_substs(db, type_, &opaque_ty.parameters, cb);
-                }
-                Ty::Placeholder(_) => {
-                    if let Some(bounds) = ty.impl_trait_bounds(db) {
-                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
-                    }
-                }
-                Ty::Dyn(bounds) => {
-                    walk_bounds(db, &type_.derived(ty.clone()), bounds.as_ref(), cb);
-                }
-
-                _ => {}
-            }
-            if let Some(substs) = ty.substs() {
-                walk_substs(db, type_, &substs, cb);
-            }
-        }
-
-        walk_type(db, self, &mut cb);
-    }
-}
-
-impl HirDisplay for Type {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        self.ty.value.hir_fmt(f)
-    }
-}
-
-// FIXME: closures
-#[derive(Debug)]
-pub struct Callable {
-    ty: Type,
-    sig: CallableSig,
-    def: Option<CallableDefId>,
-    pub(crate) is_bound_method: bool,
-}
-
-pub enum CallableKind {
-    Function(Function),
-    TupleStruct(Struct),
-    TupleEnumVariant(Variant),
-    Closure,
-}
-
-impl Callable {
-    pub fn kind(&self) -> CallableKind {
-        match self.def {
-            Some(CallableDefId::FunctionId(it)) => CallableKind::Function(it.into()),
-            Some(CallableDefId::StructId(it)) => CallableKind::TupleStruct(it.into()),
-            Some(CallableDefId::EnumVariantId(it)) => CallableKind::TupleEnumVariant(it.into()),
-            None => CallableKind::Closure,
-        }
-    }
-    pub fn receiver_param(&self, db: &dyn HirDatabase) -> Option<ast::SelfParam> {
-        let func = match self.def {
-            Some(CallableDefId::FunctionId(it)) if self.is_bound_method => it,
-            _ => return None,
-        };
-        let src = func.lookup(db.upcast()).source(db.upcast());
-        let param_list = src.value.param_list()?;
-        param_list.self_param()
-    }
-    pub fn n_params(&self) -> usize {
-        self.sig.params().len() - if self.is_bound_method { 1 } else { 0 }
-    }
-    pub fn params(
-        &self,
-        db: &dyn HirDatabase,
-    ) -> Vec<(Option<Either<ast::SelfParam, ast::Pat>>, Type)> {
-        let types = self
-            .sig
-            .params()
-            .iter()
-            .skip(if self.is_bound_method { 1 } else { 0 })
-            .map(|ty| self.ty.derived(ty.clone()));
-        let patterns = match self.def {
-            Some(CallableDefId::FunctionId(func)) => {
-                let src = func.lookup(db.upcast()).source(db.upcast());
-                src.value.param_list().map(|param_list| {
-                    param_list
-                        .self_param()
-                        .map(|it| Some(Either::Left(it)))
-                        .filter(|_| !self.is_bound_method)
-                        .into_iter()
-                        .chain(param_list.params().map(|it| it.pat().map(Either::Right)))
-                })
-            }
-            _ => None,
-        };
-        patterns.into_iter().flatten().chain(iter::repeat(None)).zip(types).collect()
-    }
-    pub fn return_type(&self) -> Type {
-        self.ty.derived(self.sig.ret().clone())
-    }
-}
-
-/// For IDE only
-#[derive(Debug, PartialEq, Eq, Hash)]
-pub enum ScopeDef {
-    ModuleDef(ModuleDef),
-    MacroDef(MacroDef),
-    GenericParam(GenericParam),
-    ImplSelfType(Impl),
-    AdtSelfType(Adt),
-    Local(Local),
-    Unknown,
-}
-
-impl ScopeDef {
-    pub fn all_items(def: PerNs) -> ArrayVec<[Self; 3]> {
-        let mut items = ArrayVec::new();
-
-        match (def.take_types(), def.take_values()) {
-            (Some(m1), None) => items.push(ScopeDef::ModuleDef(m1.into())),
-            (None, Some(m2)) => items.push(ScopeDef::ModuleDef(m2.into())),
-            (Some(m1), Some(m2)) => {
-                // Some items, like unit structs and enum variants, are
-                // returned as both a type and a value. Here we want
-                // to de-duplicate them.
-                if m1 != m2 {
-                    items.push(ScopeDef::ModuleDef(m1.into()));
-                    items.push(ScopeDef::ModuleDef(m2.into()));
-                } else {
-                    items.push(ScopeDef::ModuleDef(m1.into()));
-                }
-            }
-            (None, None) => {}
-        };
-
-        if let Some(macro_def_id) = def.take_macros() {
-            items.push(ScopeDef::MacroDef(macro_def_id.into()));
-        }
-
-        if items.is_empty() {
-            items.push(ScopeDef::Unknown);
-        }
-
-        items
-    }
-}
-
-pub trait HasVisibility {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility;
-    fn is_visible_from(&self, db: &dyn HirDatabase, module: Module) -> bool {
-        let vis = self.visibility(db);
-        vis.is_visible_from(db.upcast(), module.id)
-    }
-}
diff --git a/crates/hir/src/from_id.rs b/crates/hir/src/from_id.rs
index b5814da11..179b9d51e 100644
--- a/crates/hir/src/from_id.rs
+++ b/crates/hir/src/from_id.rs
@@ -11,9 +11,8 @@ use hir_def::{
 };
 
 use crate::{
-    code_model::{BuiltinType, GenericParam},
-    Adt, AssocItem, DefWithBody, Field, GenericDef, Label, Local, MacroDef, ModuleDef, Variant,
-    VariantDef,
+    Adt, AssocItem, BuiltinType, DefWithBody, Field, GenericDef, GenericParam, Label, Local,
+    MacroDef, ModuleDef, Variant, VariantDef,
 };
 
 macro_rules! from_id {
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 69fcdab07..58adc8fd3 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -20,49 +20,2117 @@
 #![recursion_limit = "512"]
 
 mod semantics;
-pub mod db;
 mod source_analyzer;
 
-pub mod diagnostics;
-
 mod from_id;
-mod code_model;
 mod attrs;
 mod has_source;
 
+pub mod diagnostics;
+pub mod db;
+
+use std::{iter, sync::Arc};
+
+use arrayvec::ArrayVec;
+use base_db::{CrateDisplayName, CrateId, Edition, FileId};
+use either::Either;
+use hir_def::{
+    adt::{ReprKind, VariantData},
+    expr::{BindingAnnotation, LabelId, Pat, PatId},
+    item_tree::ItemTreeNode,
+    lang_item::LangItemTarget,
+    per_ns::PerNs,
+    resolver::{HasResolver, Resolver},
+    src::HasSource as _,
+    AdtId, AssocContainerId, AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId,
+    DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule, ImplId, LifetimeParamId,
+    LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
+    TypeParamId, UnionId,
+};
+use hir_expand::{diagnostics::DiagnosticSink, name::name, MacroDefKind};
+use hir_ty::{
+    autoderef,
+    display::{write_bounds_like_dyn_trait_with_prefix, HirDisplayError, HirFormatter},
+    method_resolution,
+    traits::{FnTrait, Solution, SolutionVariables},
+    AliasTy, BoundVar, CallableDefId, CallableSig, Canonical, DebruijnIndex, GenericPredicate,
+    InEnvironment, Obligation, ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitEnvironment,
+    Ty, TyDefId, TyVariableKind,
+};
+use rustc_hash::FxHashSet;
+use stdx::{format_to, impl_from};
+use syntax::{
+    ast::{self, AttrsOwner, NameOwner},
+    AstNode, SmolStr,
+};
+use tt::{Ident, Leaf, Literal, TokenTree};
+
+use crate::db::{DefDatabase, HirDatabase};
+
 pub use crate::{
     attrs::{HasAttrs, Namespace},
-    code_model::{
-        Access, Adt, AsAssocItem, AssocItem, AssocItemContainer, BuiltinType, Callable,
-        CallableKind, Const, ConstParam, Crate, CrateDependency, DefWithBody, Enum, Field,
-        FieldSource, Function, GenericDef, GenericParam, HasVisibility, Impl, Label, LifetimeParam,
-        Local, MacroDef, Module, ModuleDef, ScopeDef, Static, Struct, Trait, Type, TypeAlias,
-        TypeParam, Union, Variant, VariantDef,
-    },
     has_source::HasSource,
     semantics::{PathResolution, Semantics, SemanticsScope},
 };
 
-pub use hir_def::{
-    adt::StructKind,
-    attr::{Attrs, Documentation},
-    body::scope::ExprScopes,
-    find_path::PrefixKind,
-    import_map,
-    item_scope::ItemInNs,
-    nameres::ModuleSource,
-    path::{ModPath, PathKind},
-    type_ref::{Mutability, TypeRef},
-    visibility::Visibility,
-};
-pub use hir_expand::{
-    name::{known, AsName, Name},
-    ExpandResult, HirFileId, InFile, MacroCallId, MacroCallLoc, /* FIXME */ MacroDefId,
-    MacroFile, Origin,
+// Be careful with these re-exports.
+//
+// `hir` is the boundary between the compiler and the IDE. It should try hard to
+// isolate the compiler from the ide, to allow the two to be refactored
+// independently. Re-exporting something from the compiler is the sure way to
+// breach the boundary.
+//
+// Generally, a refactoring which *removes* a name from this list is a good
+// idea!
+pub use {
+    hir_def::{
+        adt::StructKind,
+        attr::{Attrs, Documentation},
+        body::scope::ExprScopes,
+        find_path::PrefixKind,
+        import_map,
+        item_scope::ItemInNs,
+        nameres::ModuleSource,
+        path::{ModPath, PathKind},
+        type_ref::{Mutability, TypeRef},
+        visibility::Visibility,
+    },
+    hir_expand::{
+        name::{known, Name},
+        ExpandResult, HirFileId, InFile, MacroCallId, MacroCallLoc, /* FIXME */ MacroDefId,
+        MacroFile, Origin,
+    },
+    hir_ty::display::HirDisplay,
 };
-pub use hir_ty::display::HirDisplay;
 
 // These are negative re-exports: pub using these names is forbidden, they
 // should remain private to hir internals.
 #[allow(unused)]
-use {hir_def::path::Path, hir_expand::hygiene::Hygiene};
+use {
+    hir_def::path::Path,
+    hir_expand::{hygiene::Hygiene, name::AsName},
+};
+
+/// hir::Crate describes a single crate. It's the main interface with which
+/// a crate's dependencies interact. Mostly, it should be just a proxy for the
+/// root module.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Crate {
+    pub(crate) id: CrateId,
+}
+
+#[derive(Debug)]
+pub struct CrateDependency {
+    pub krate: Crate,
+    pub name: Name,
+}
+
+impl Crate {
+    pub fn dependencies(self, db: &dyn HirDatabase) -> Vec<CrateDependency> {
+        db.crate_graph()[self.id]
+            .dependencies
+            .iter()
+            .map(|dep| {
+                let krate = Crate { id: dep.crate_id };
+                let name = dep.as_name();
+                CrateDependency { krate, name }
+            })
+            .collect()
+    }
+
+    // FIXME: add `transitive_reverse_dependencies`.
+    pub fn reverse_dependencies(self, db: &dyn HirDatabase) -> Vec<Crate> {
+        let crate_graph = db.crate_graph();
+        crate_graph
+            .iter()
+            .filter(|&krate| {
+                crate_graph[krate].dependencies.iter().any(|it| it.crate_id == self.id)
+            })
+            .map(|id| Crate { id })
+            .collect()
+    }
+
+    pub fn root_module(self, db: &dyn HirDatabase) -> Module {
+        let def_map = db.crate_def_map(self.id);
+        Module { id: def_map.module_id(def_map.root()) }
+    }
+
+    pub fn root_file(self, db: &dyn HirDatabase) -> FileId {
+        db.crate_graph()[self.id].root_file_id
+    }
+
+    pub fn edition(self, db: &dyn HirDatabase) -> Edition {
+        db.crate_graph()[self.id].edition
+    }
+
+    pub fn display_name(self, db: &dyn HirDatabase) -> Option<CrateDisplayName> {
+        db.crate_graph()[self.id].display_name.clone()
+    }
+
+    pub fn query_external_importables(
+        self,
+        db: &dyn DefDatabase,
+        query: import_map::Query,
+    ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+        import_map::search_dependencies(db, self.into(), query).into_iter().map(|item| match item {
+            ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
+            ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
+        })
+    }
+
+    pub fn all(db: &dyn HirDatabase) -> Vec<Crate> {
+        db.crate_graph().iter().map(|id| Crate { id }).collect()
+    }
+
+    /// Try to get the root URL of the documentation of a crate.
+    pub fn get_html_root_url(self: &Crate, db: &dyn HirDatabase) -> Option<String> {
+        // Look for #![doc(html_root_url = "...")]
+        let attrs = db.attrs(AttrDefId::ModuleId(self.root_module(db).into()));
+        let doc_attr_q = attrs.by_key("doc");
+
+        if !doc_attr_q.exists() {
+            return None;
+        }
+
+        let doc_url = doc_attr_q.tt_values().map(|tt| {
+            let name = tt.token_trees.iter()
+                .skip_while(|tt| !matches!(tt, TokenTree::Leaf(Leaf::Ident(Ident{text: ref ident, ..})) if ident == "html_root_url"))
+                .skip(2)
+                .next();
+
+            match name {
+                Some(TokenTree::Leaf(Leaf::Literal(Literal{ref text, ..}))) => Some(text),
+                _ => None
+            }
+        }).flat_map(|t| t).next();
+
+        doc_url.map(|s| s.trim_matches('"').trim_end_matches('/').to_owned() + "/")
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Module {
+    pub(crate) id: ModuleId,
+}
+
+/// The defs which can be visible in the module.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ModuleDef {
+    Module(Module),
+    Function(Function),
+    Adt(Adt),
+    // Can't be directly declared, but can be imported.
+    Variant(Variant),
+    Const(Const),
+    Static(Static),
+    Trait(Trait),
+    TypeAlias(TypeAlias),
+    BuiltinType(BuiltinType),
+}
+impl_from!(
+    Module,
+    Function,
+    Adt(Struct, Enum, Union),
+    Variant,
+    Const,
+    Static,
+    Trait,
+    TypeAlias,
+    BuiltinType
+    for ModuleDef
+);
+
+impl From<VariantDef> for ModuleDef {
+    fn from(var: VariantDef) -> Self {
+        match var {
+            VariantDef::Struct(t) => Adt::from(t).into(),
+            VariantDef::Union(t) => Adt::from(t).into(),
+            VariantDef::Variant(t) => t.into(),
+        }
+    }
+}
+
+impl ModuleDef {
+    pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
+        match self {
+            ModuleDef::Module(it) => it.parent(db),
+            ModuleDef::Function(it) => Some(it.module(db)),
+            ModuleDef::Adt(it) => Some(it.module(db)),
+            ModuleDef::Variant(it) => Some(it.module(db)),
+            ModuleDef::Const(it) => Some(it.module(db)),
+            ModuleDef::Static(it) => Some(it.module(db)),
+            ModuleDef::Trait(it) => Some(it.module(db)),
+            ModuleDef::TypeAlias(it) => Some(it.module(db)),
+            ModuleDef::BuiltinType(_) => None,
+        }
+    }
+
+    pub fn canonical_path(&self, db: &dyn HirDatabase) -> Option<String> {
+        let mut segments = Vec::new();
+        segments.push(self.name(db)?.to_string());
+        for m in self.module(db)?.path_to_root(db) {
+            segments.extend(m.name(db).map(|it| it.to_string()))
+        }
+        segments.reverse();
+        Some(segments.join("::"))
+    }
+
+    pub fn definition_visibility(&self, db: &dyn HirDatabase) -> Option<Visibility> {
+        let module = match self {
+            ModuleDef::Module(it) => it.parent(db)?,
+            ModuleDef::Function(it) => return Some(it.visibility(db)),
+            ModuleDef::Adt(it) => it.module(db),
+            ModuleDef::Variant(it) => {
+                let parent = it.parent_enum(db);
+                let module = it.module(db);
+                return module.visibility_of(db, &ModuleDef::Adt(Adt::Enum(parent)));
+            }
+            ModuleDef::Const(it) => return Some(it.visibility(db)),
+            ModuleDef::Static(it) => it.module(db),
+            ModuleDef::Trait(it) => it.module(db),
+            ModuleDef::TypeAlias(it) => return Some(it.visibility(db)),
+            ModuleDef::BuiltinType(_) => return None,
+        };
+
+        module.visibility_of(db, self)
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        match self {
+            ModuleDef::Adt(it) => Some(it.name(db)),
+            ModuleDef::Trait(it) => Some(it.name(db)),
+            ModuleDef::Function(it) => Some(it.name(db)),
+            ModuleDef::Variant(it) => Some(it.name(db)),
+            ModuleDef::TypeAlias(it) => Some(it.name(db)),
+            ModuleDef::Module(it) => it.name(db),
+            ModuleDef::Const(it) => it.name(db),
+            ModuleDef::Static(it) => it.name(db),
+            ModuleDef::BuiltinType(it) => Some(it.name()),
+        }
+    }
+
+    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+        let id = match self {
+            ModuleDef::Adt(it) => match it {
+                Adt::Struct(it) => it.id.into(),
+                Adt::Enum(it) => it.id.into(),
+                Adt::Union(it) => it.id.into(),
+            },
+            ModuleDef::Trait(it) => it.id.into(),
+            ModuleDef::Function(it) => it.id.into(),
+            ModuleDef::TypeAlias(it) => it.id.into(),
+            ModuleDef::Module(it) => it.id.into(),
+            ModuleDef::Const(it) => it.id.into(),
+            ModuleDef::Static(it) => it.id.into(),
+            _ => return,
+        };
+
+        let module = match self.module(db) {
+            Some(it) => it,
+            None => return,
+        };
+
+        hir_ty::diagnostics::validate_module_item(db, module.id.krate(), id, sink)
+    }
+}
+
+impl Module {
+    /// Name of this module.
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        let def_map = self.id.def_map(db.upcast());
+        let parent = def_map[self.id.local_id].parent?;
+        def_map[parent].children.iter().find_map(|(name, module_id)| {
+            if *module_id == self.id.local_id {
+                Some(name.clone())
+            } else {
+                None
+            }
+        })
+    }
+
+    /// Returns the crate this module is part of.
+    pub fn krate(self) -> Crate {
+        Crate { id: self.id.krate() }
+    }
+
+    /// Topmost parent of this module. Every module has a `crate_root`, but some
+    /// might be missing `krate`. This can happen if a module's file is not included
+    /// in the module tree of any target in `Cargo.toml`.
+    pub fn crate_root(self, db: &dyn HirDatabase) -> Module {
+        let def_map = db.crate_def_map(self.id.krate());
+        Module { id: def_map.module_id(def_map.root()) }
+    }
+
+    /// Iterates over all child modules.
+    pub fn children(self, db: &dyn HirDatabase) -> impl Iterator<Item = Module> {
+        let def_map = self.id.def_map(db.upcast());
+        let children = def_map[self.id.local_id]
+            .children
+            .iter()
+            .map(|(_, module_id)| Module { id: def_map.module_id(*module_id) })
+            .collect::<Vec<_>>();
+        children.into_iter()
+    }
+
+    /// Finds a parent module.
+    pub fn parent(self, db: &dyn HirDatabase) -> Option<Module> {
+        // FIXME: handle block expressions as modules (their parent is in a different DefMap)
+        let def_map = self.id.def_map(db.upcast());
+        let parent_id = def_map[self.id.local_id].parent?;
+        Some(Module { id: def_map.module_id(parent_id) })
+    }
+
+    pub fn path_to_root(self, db: &dyn HirDatabase) -> Vec<Module> {
+        let mut res = vec![self];
+        let mut curr = self;
+        while let Some(next) = curr.parent(db) {
+            res.push(next);
+            curr = next
+        }
+        res
+    }
+
+    /// Returns a `ModuleScope`: a set of items, visible in this module.
+    pub fn scope(
+        self,
+        db: &dyn HirDatabase,
+        visible_from: Option<Module>,
+    ) -> Vec<(Name, ScopeDef)> {
+        self.id.def_map(db.upcast())[self.id.local_id]
+            .scope
+            .entries()
+            .filter_map(|(name, def)| {
+                if let Some(m) = visible_from {
+                    let filtered =
+                        def.filter_visibility(|vis| vis.is_visible_from(db.upcast(), m.id));
+                    if filtered.is_none() && !def.is_none() {
+                        None
+                    } else {
+                        Some((name, filtered))
+                    }
+                } else {
+                    Some((name, def))
+                }
+            })
+            .flat_map(|(name, def)| {
+                ScopeDef::all_items(def).into_iter().map(move |item| (name.clone(), item))
+            })
+            .collect()
+    }
+
+    pub fn visibility_of(self, db: &dyn HirDatabase, def: &ModuleDef) -> Option<Visibility> {
+        self.id.def_map(db.upcast())[self.id.local_id].scope.visibility_of(def.clone().into())
+    }
+
+    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+        let _p = profile::span("Module::diagnostics").detail(|| {
+            format!("{:?}", self.name(db).map_or("<unknown>".into(), |name| name.to_string()))
+        });
+        let def_map = self.id.def_map(db.upcast());
+        def_map.add_diagnostics(db.upcast(), self.id.local_id, sink);
+        for decl in self.declarations(db) {
+            match decl {
+                crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
+                crate::ModuleDef::Module(m) => {
+                    // Only add diagnostics from inline modules
+                    if def_map[m.id.local_id].origin.is_inline() {
+                        m.diagnostics(db, sink)
+                    }
+                }
+                _ => {
+                    decl.diagnostics(db, sink);
+                }
+            }
+        }
+
+        for impl_def in self.impl_defs(db) {
+            for item in impl_def.items(db) {
+                if let AssocItem::Function(f) = item {
+                    f.diagnostics(db, sink);
+                }
+            }
+        }
+    }
+
+    pub fn declarations(self, db: &dyn HirDatabase) -> Vec<ModuleDef> {
+        let def_map = self.id.def_map(db.upcast());
+        def_map[self.id.local_id].scope.declarations().map(ModuleDef::from).collect()
+    }
+
+    pub fn impl_defs(self, db: &dyn HirDatabase) -> Vec<Impl> {
+        let def_map = self.id.def_map(db.upcast());
+        def_map[self.id.local_id].scope.impls().map(Impl::from).collect()
+    }
+
+    /// Finds a path that can be used to refer to the given item from within
+    /// this module, if possible.
+    pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
+        hir_def::find_path::find_path(db, item.into(), self.into())
+    }
+
+    /// Finds a path that can be used to refer to the given item from within
+    /// this module, if possible. This is used for returning import paths for use-statements.
+    pub fn find_use_path_prefixed(
+        self,
+        db: &dyn DefDatabase,
+        item: impl Into<ItemInNs>,
+        prefix_kind: PrefixKind,
+    ) -> Option<ModPath> {
+        hir_def::find_path::find_path_prefixed(db, item.into(), self.into(), prefix_kind)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Field {
+    pub(crate) parent: VariantDef,
+    pub(crate) id: LocalFieldId,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum FieldSource {
+    Named(ast::RecordField),
+    Pos(ast::TupleField),
+}
+
+impl Field {
+    pub fn name(&self, db: &dyn HirDatabase) -> Name {
+        self.parent.variant_data(db).fields()[self.id].name.clone()
+    }
+
+    /// Returns the type as in the signature of the struct (i.e., with
+    /// placeholder types for type parameters). This is good for showing
+    /// signature help, but not so good to actually get the type of the field
+    /// when you actually have a variable of the struct.
+    pub fn signature_ty(&self, db: &dyn HirDatabase) -> Type {
+        let var_id = self.parent.into();
+        let generic_def_id: GenericDefId = match self.parent {
+            VariantDef::Struct(it) => it.id.into(),
+            VariantDef::Union(it) => it.id.into(),
+            VariantDef::Variant(it) => it.parent.id.into(),
+        };
+        let substs = Substs::type_params(db, generic_def_id);
+        let ty = db.field_types(var_id)[self.id].clone().subst(&substs);
+        Type::new(db, self.parent.module(db).id.krate(), var_id, ty)
+    }
+
+    pub fn parent_def(&self, _db: &dyn HirDatabase) -> VariantDef {
+        self.parent
+    }
+}
+
+impl HasVisibility for Field {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        let variant_data = self.parent.variant_data(db);
+        let visibility = &variant_data.fields()[self.id].visibility;
+        let parent_id: hir_def::VariantId = self.parent.into();
+        visibility.resolve(db.upcast(), &parent_id.resolver(db.upcast()))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Struct {
+    pub(crate) id: StructId,
+}
+
+impl Struct {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).container }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.struct_data(self.id).name.clone()
+    }
+
+    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
+        db.struct_data(self.id)
+            .variant_data
+            .fields()
+            .iter()
+            .map(|(id, _)| Field { parent: self.into(), id })
+            .collect()
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        Type::from_def(db, self.id.lookup(db.upcast()).container.krate(), self.id)
+    }
+
+    pub fn repr(self, db: &dyn HirDatabase) -> Option<ReprKind> {
+        db.struct_data(self.id).repr.clone()
+    }
+
+    pub fn kind(self, db: &dyn HirDatabase) -> StructKind {
+        self.variant_data(db).kind()
+    }
+
+    fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
+        db.struct_data(self.id).variant_data.clone()
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Union {
+    pub(crate) id: UnionId,
+}
+
+impl Union {
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.union_data(self.id).name.clone()
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).container }
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        Type::from_def(db, self.id.lookup(db.upcast()).container.krate(), self.id)
+    }
+
+    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
+        db.union_data(self.id)
+            .variant_data
+            .fields()
+            .iter()
+            .map(|(id, _)| Field { parent: self.into(), id })
+            .collect()
+    }
+
+    fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
+        db.union_data(self.id).variant_data.clone()
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Enum {
+    pub(crate) id: EnumId,
+}
+
+impl Enum {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).container }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.enum_data(self.id).name.clone()
+    }
+
+    pub fn variants(self, db: &dyn HirDatabase) -> Vec<Variant> {
+        db.enum_data(self.id).variants.iter().map(|(id, _)| Variant { parent: self, id }).collect()
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        Type::from_def(db, self.id.lookup(db.upcast()).container.krate(), self.id)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Variant {
+    pub(crate) parent: Enum,
+    pub(crate) id: LocalEnumVariantId,
+}
+
+impl Variant {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.parent.module(db)
+    }
+    pub fn parent_enum(self, _db: &dyn HirDatabase) -> Enum {
+        self.parent
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.enum_data(self.parent.id).variants[self.id].name.clone()
+    }
+
+    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
+        self.variant_data(db)
+            .fields()
+            .iter()
+            .map(|(id, _)| Field { parent: self.into(), id })
+            .collect()
+    }
+
+    pub fn kind(self, db: &dyn HirDatabase) -> StructKind {
+        self.variant_data(db).kind()
+    }
+
+    pub(crate) fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
+        db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
+    }
+}
+
+/// A Data Type
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum Adt {
+    Struct(Struct),
+    Union(Union),
+    Enum(Enum),
+}
+impl_from!(Struct, Union, Enum for Adt);
+
+impl Adt {
+    pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
+        let subst = db.generic_defaults(self.into());
+        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
+    }
+
+    /// Turns this ADT into a type. Any type parameters of the ADT will be
+    /// turned into unknown types, which is good for e.g. finding the most
+    /// general set of completions, but will not look very nice when printed.
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let id = AdtId::from(self);
+        Type::from_def(db, id.module(db.upcast()).krate(), id)
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            Adt::Struct(s) => s.module(db),
+            Adt::Union(s) => s.module(db),
+            Adt::Enum(e) => e.module(db),
+        }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        match self {
+            Adt::Struct(s) => s.name(db),
+            Adt::Union(u) => u.name(db),
+            Adt::Enum(e) => e.name(db),
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum VariantDef {
+    Struct(Struct),
+    Union(Union),
+    Variant(Variant),
+}
+impl_from!(Struct, Union, Variant for VariantDef);
+
+impl VariantDef {
+    pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
+        match self {
+            VariantDef::Struct(it) => it.fields(db),
+            VariantDef::Union(it) => it.fields(db),
+            VariantDef::Variant(it) => it.fields(db),
+        }
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            VariantDef::Struct(it) => it.module(db),
+            VariantDef::Union(it) => it.module(db),
+            VariantDef::Variant(it) => it.module(db),
+        }
+    }
+
+    pub fn name(&self, db: &dyn HirDatabase) -> Name {
+        match self {
+            VariantDef::Struct(s) => s.name(db),
+            VariantDef::Union(u) => u.name(db),
+            VariantDef::Variant(e) => e.name(db),
+        }
+    }
+
+    pub(crate) fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
+        match self {
+            VariantDef::Struct(it) => it.variant_data(db),
+            VariantDef::Union(it) => it.variant_data(db),
+            VariantDef::Variant(it) => it.variant_data(db),
+        }
+    }
+}
+
+/// The defs which have a body.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum DefWithBody {
+    Function(Function),
+    Static(Static),
+    Const(Const),
+}
+impl_from!(Function, Const, Static for DefWithBody);
+
+impl DefWithBody {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            DefWithBody::Const(c) => c.module(db),
+            DefWithBody::Function(f) => f.module(db),
+            DefWithBody::Static(s) => s.module(db),
+        }
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        match self {
+            DefWithBody::Function(f) => Some(f.name(db)),
+            DefWithBody::Static(s) => s.name(db),
+            DefWithBody::Const(c) => c.name(db),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Function {
+    pub(crate) id: FunctionId,
+}
+
+impl Function {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.id.lookup(db.upcast()).module(db.upcast()).into()
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.function_data(self.id).name.clone()
+    }
+
+    /// Get this function's return type
+    pub fn ret_type(self, db: &dyn HirDatabase) -> Type {
+        let resolver = self.id.resolver(db.upcast());
+        let krate = self.id.lookup(db.upcast()).container.module(db.upcast()).krate();
+        let ret_type = &db.function_data(self.id).ret_type;
+        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
+        let ty = Ty::from_hir_ext(&ctx, ret_type).0;
+        Type::new_with_resolver_inner(db, krate, &resolver, ty)
+    }
+
+    pub fn self_param(self, db: &dyn HirDatabase) -> Option<SelfParam> {
+        if !db.function_data(self.id).has_self_param {
+            return None;
+        }
+        Some(SelfParam { func: self.id })
+    }
+
+    pub fn assoc_fn_params(self, db: &dyn HirDatabase) -> Vec<Param> {
+        let resolver = self.id.resolver(db.upcast());
+        let krate = self.id.lookup(db.upcast()).container.module(db.upcast()).krate();
+        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
+        let environment = TraitEnvironment::lower(db, &resolver);
+        db.function_data(self.id)
+            .params
+            .iter()
+            .map(|type_ref| {
+                let ty = Type {
+                    krate,
+                    ty: InEnvironment {
+                        value: Ty::from_hir_ext(&ctx, type_ref).0,
+                        environment: environment.clone(),
+                    },
+                };
+                Param { ty }
+            })
+            .collect()
+    }
+    pub fn method_params(self, db: &dyn HirDatabase) -> Option<Vec<Param>> {
+        if self.self_param(db).is_none() {
+            return None;
+        }
+        let mut res = self.assoc_fn_params(db);
+        res.remove(0);
+        Some(res)
+    }
+
+    pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
+        db.function_data(self.id).is_unsafe
+    }
+
+    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+        let krate = self.module(db).id.krate();
+        hir_def::diagnostics::validate_body(db.upcast(), self.id.into(), sink);
+        hir_ty::diagnostics::validate_module_item(db, krate, self.id.into(), sink);
+        hir_ty::diagnostics::validate_body(db, self.id.into(), sink);
+    }
+
+    /// Whether this function declaration has a definition.
+    ///
+    /// This is false in the case of required (not provided) trait methods.
+    pub fn has_body(self, db: &dyn HirDatabase) -> bool {
+        db.function_data(self.id).has_body
+    }
+
+    /// A textual representation of the HIR of this function for debugging purposes.
+    pub fn debug_hir(self, db: &dyn HirDatabase) -> String {
+        let body = db.body(self.id.into());
+
+        let mut result = String::new();
+        format_to!(result, "HIR expressions in the body of `{}`:\n", self.name(db));
+        for (id, expr) in body.exprs.iter() {
+            format_to!(result, "{:?}: {:?}\n", id, expr);
+        }
+
+        result
+    }
+}
+
+// Note: logically, this belongs to `hir_ty`, but we are not using it there yet.
+pub enum Access {
+    Shared,
+    Exclusive,
+    Owned,
+}
+
+impl From<hir_ty::Mutability> for Access {
+    fn from(mutability: hir_ty::Mutability) -> Access {
+        match mutability {
+            hir_ty::Mutability::Not => Access::Shared,
+            hir_ty::Mutability::Mut => Access::Exclusive,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Param {
+    ty: Type,
+}
+
+impl Param {
+    pub fn ty(&self) -> &Type {
+        &self.ty
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct SelfParam {
+    func: FunctionId,
+}
+
+impl SelfParam {
+    pub fn access(self, db: &dyn HirDatabase) -> Access {
+        let func_data = db.function_data(self.func);
+        func_data
+            .params
+            .first()
+            .map(|param| match *param {
+                TypeRef::Reference(.., mutability) => match mutability {
+                    hir_def::type_ref::Mutability::Shared => Access::Shared,
+                    hir_def::type_ref::Mutability::Mut => Access::Exclusive,
+                },
+                _ => Access::Owned,
+            })
+            .unwrap_or(Access::Owned)
+    }
+}
+
+impl HasVisibility for Function {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        let function_data = db.function_data(self.id);
+        let visibility = &function_data.visibility;
+        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Const {
+    pub(crate) id: ConstId,
+}
+
+impl Const {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        db.const_data(self.id).name.clone()
+    }
+}
+
+impl HasVisibility for Const {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        let function_data = db.const_data(self.id);
+        let visibility = &function_data.visibility;
+        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Static {
+    pub(crate) id: StaticId,
+}
+
+impl Static {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        db.static_data(self.id).name.clone()
+    }
+
+    pub fn is_mut(self, db: &dyn HirDatabase) -> bool {
+        db.static_data(self.id).mutable
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Trait {
+    pub(crate) id: TraitId,
+}
+
+impl Trait {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).container }
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.trait_data(self.id).name.clone()
+    }
+
+    pub fn items(self, db: &dyn HirDatabase) -> Vec<AssocItem> {
+        db.trait_data(self.id).items.iter().map(|(_name, it)| (*it).into()).collect()
+    }
+
+    pub fn is_auto(self, db: &dyn HirDatabase) -> bool {
+        db.trait_data(self.id).auto
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct TypeAlias {
+    pub(crate) id: TypeAliasId,
+}
+
+impl TypeAlias {
+    pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
+        let subst = db.generic_defaults(self.id.into());
+        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        Module { id: self.id.lookup(db.upcast()).module(db.upcast()) }
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Option<Crate> {
+        Some(self.module(db).krate())
+    }
+
+    pub fn type_ref(self, db: &dyn HirDatabase) -> Option<TypeRef> {
+        db.type_alias_data(self.id).type_ref.clone()
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        Type::from_def(db, self.id.lookup(db.upcast()).module(db.upcast()).krate(), self.id)
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        db.type_alias_data(self.id).name.clone()
+    }
+}
+
+impl HasVisibility for TypeAlias {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        let function_data = db.type_alias_data(self.id);
+        let visibility = &function_data.visibility;
+        visibility.resolve(db.upcast(), &self.id.resolver(db.upcast()))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct BuiltinType {
+    pub(crate) inner: hir_def::builtin_type::BuiltinType,
+}
+
+impl BuiltinType {
+    pub fn ty(self, db: &dyn HirDatabase, module: Module) -> Type {
+        let resolver = module.id.resolver(db.upcast());
+        Type::new_with_resolver(db, &resolver, Ty::builtin(self.inner))
+            .expect("crate not present in resolver")
+    }
+
+    pub fn name(self) -> Name {
+        self.inner.as_name()
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct MacroDef {
+    pub(crate) id: MacroDefId,
+}
+
+impl MacroDef {
+    /// FIXME: right now, this just returns the root module of the crate that
+    /// defines this macro. The reasons for this is that macros are expanded
+    /// early, in `hir_expand`, where modules simply do not exist yet.
+    pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
+        let krate = self.id.krate;
+        let def_map = db.crate_def_map(krate);
+        let module_id = def_map.root();
+        Some(Module { id: def_map.module_id(module_id) })
+    }
+
+    /// XXX: this parses the file
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        self.source(db)?.value.name().map(|it| it.as_name())
+    }
+
+    /// Indicate it is a proc-macro
+    pub fn is_proc_macro(&self) -> bool {
+        matches!(self.id.kind, MacroDefKind::ProcMacro(_))
+    }
+
+    /// Indicate it is a derive macro
+    pub fn is_derive_macro(&self) -> bool {
+        matches!(self.id.kind, MacroDefKind::ProcMacro(_) | MacroDefKind::BuiltInDerive(_))
+    }
+}
+
+/// Invariant: `inner.as_assoc_item(db).is_some()`
+/// We do not actively enforce this invariant.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub enum AssocItem {
+    Function(Function),
+    Const(Const),
+    TypeAlias(TypeAlias),
+}
+#[derive(Debug)]
+pub enum AssocItemContainer {
+    Trait(Trait),
+    Impl(Impl),
+}
+pub trait AsAssocItem {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem>;
+}
+
+impl AsAssocItem for Function {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::Function, self.id)
+    }
+}
+impl AsAssocItem for Const {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::Const, self.id)
+    }
+}
+impl AsAssocItem for TypeAlias {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        as_assoc_item(db, AssocItem::TypeAlias, self.id)
+    }
+}
+impl AsAssocItem for ModuleDef {
+    fn as_assoc_item(self, db: &dyn HirDatabase) -> Option<AssocItem> {
+        match self {
+            ModuleDef::Function(it) => it.as_assoc_item(db),
+            ModuleDef::Const(it) => it.as_assoc_item(db),
+            ModuleDef::TypeAlias(it) => it.as_assoc_item(db),
+            _ => None,
+        }
+    }
+}
+fn as_assoc_item<ID, DEF, CTOR, AST>(db: &dyn HirDatabase, ctor: CTOR, id: ID) -> Option<AssocItem>
+where
+    ID: Lookup<Data = AssocItemLoc<AST>>,
+    DEF: From<ID>,
+    CTOR: FnOnce(DEF) -> AssocItem,
+    AST: ItemTreeNode,
+{
+    match id.lookup(db.upcast()).container {
+        AssocContainerId::TraitId(_) | AssocContainerId::ImplId(_) => Some(ctor(DEF::from(id))),
+        AssocContainerId::ModuleId(_) => None,
+    }
+}
+
+impl AssocItem {
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        match self {
+            AssocItem::Function(it) => Some(it.name(db)),
+            AssocItem::Const(it) => it.name(db),
+            AssocItem::TypeAlias(it) => Some(it.name(db)),
+        }
+    }
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            AssocItem::Function(f) => f.module(db),
+            AssocItem::Const(c) => c.module(db),
+            AssocItem::TypeAlias(t) => t.module(db),
+        }
+    }
+    pub fn container(self, db: &dyn HirDatabase) -> AssocItemContainer {
+        let container = match self {
+            AssocItem::Function(it) => it.id.lookup(db.upcast()).container,
+            AssocItem::Const(it) => it.id.lookup(db.upcast()).container,
+            AssocItem::TypeAlias(it) => it.id.lookup(db.upcast()).container,
+        };
+        match container {
+            AssocContainerId::TraitId(id) => AssocItemContainer::Trait(id.into()),
+            AssocContainerId::ImplId(id) => AssocItemContainer::Impl(id.into()),
+            AssocContainerId::ModuleId(_) => panic!("invalid AssocItem"),
+        }
+    }
+
+    pub fn containing_trait(self, db: &dyn HirDatabase) -> Option<Trait> {
+        match self.container(db) {
+            AssocItemContainer::Trait(t) => Some(t),
+            _ => None,
+        }
+    }
+}
+
+impl HasVisibility for AssocItem {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        match self {
+            AssocItem::Function(f) => f.visibility(db),
+            AssocItem::Const(c) => c.visibility(db),
+            AssocItem::TypeAlias(t) => t.visibility(db),
+        }
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
+pub enum GenericDef {
+    Function(Function),
+    Adt(Adt),
+    Trait(Trait),
+    TypeAlias(TypeAlias),
+    Impl(Impl),
+    // enum variants cannot have generics themselves, but their parent enums
+    // can, and this makes some code easier to write
+    Variant(Variant),
+    // consts can have type parameters from their parents (i.e. associated consts of traits)
+    Const(Const),
+}
+impl_from!(
+    Function,
+    Adt(Struct, Enum, Union),
+    Trait,
+    TypeAlias,
+    Impl,
+    Variant,
+    Const
+    for GenericDef
+);
+
+impl GenericDef {
+    pub fn params(self, db: &dyn HirDatabase) -> Vec<GenericParam> {
+        let generics = db.generic_params(self.into());
+        let ty_params = generics
+            .types
+            .iter()
+            .map(|(local_id, _)| TypeParam { id: TypeParamId { parent: self.into(), local_id } })
+            .map(GenericParam::TypeParam);
+        let lt_params = generics
+            .lifetimes
+            .iter()
+            .map(|(local_id, _)| LifetimeParam {
+                id: LifetimeParamId { parent: self.into(), local_id },
+            })
+            .map(GenericParam::LifetimeParam);
+        let const_params = generics
+            .consts
+            .iter()
+            .map(|(local_id, _)| ConstParam { id: ConstParamId { parent: self.into(), local_id } })
+            .map(GenericParam::ConstParam);
+        ty_params.chain(lt_params).chain(const_params).collect()
+    }
+
+    pub fn type_params(self, db: &dyn HirDatabase) -> Vec<TypeParam> {
+        let generics = db.generic_params(self.into());
+        generics
+            .types
+            .iter()
+            .map(|(local_id, _)| TypeParam { id: TypeParamId { parent: self.into(), local_id } })
+            .collect()
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct Local {
+    pub(crate) parent: DefWithBodyId,
+    pub(crate) pat_id: PatId,
+}
+
+impl Local {
+    pub fn is_param(self, db: &dyn HirDatabase) -> bool {
+        let src = self.source(db);
+        match src.value {
+            Either::Left(bind_pat) => {
+                bind_pat.syntax().ancestors().any(|it| ast::Param::can_cast(it.kind()))
+            }
+            Either::Right(_self_param) => true,
+        }
+    }
+
+    // FIXME: why is this an option? It shouldn't be?
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        let body = db.body(self.parent.into());
+        match &body[self.pat_id] {
+            Pat::Bind { name, .. } => Some(name.clone()),
+            _ => None,
+        }
+    }
+
+    pub fn is_self(self, db: &dyn HirDatabase) -> bool {
+        self.name(db) == Some(name![self])
+    }
+
+    pub fn is_mut(self, db: &dyn HirDatabase) -> bool {
+        let body = db.body(self.parent.into());
+        matches!(&body[self.pat_id], Pat::Bind { mode: BindingAnnotation::Mutable, .. })
+    }
+
+    pub fn parent(self, _db: &dyn HirDatabase) -> DefWithBody {
+        self.parent.into()
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.parent(db).module(db)
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let def = DefWithBodyId::from(self.parent);
+        let infer = db.infer(def);
+        let ty = infer[self.pat_id].clone();
+        let krate = def.module(db.upcast()).krate();
+        Type::new(db, krate, def, ty)
+    }
+
+    pub fn source(self, db: &dyn HirDatabase) -> InFile<Either<ast::IdentPat, ast::SelfParam>> {
+        let (_body, source_map) = db.body_with_source_map(self.parent.into());
+        let src = source_map.pat_syntax(self.pat_id).unwrap(); // Hmm...
+        let root = src.file_syntax(db.upcast());
+        src.map(|ast| {
+            ast.map_left(|it| it.cast().unwrap().to_node(&root)).map_right(|it| it.to_node(&root))
+        })
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct Label {
+    pub(crate) parent: DefWithBodyId,
+    pub(crate) label_id: LabelId,
+}
+
+impl Label {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.parent(db).module(db)
+    }
+
+    pub fn parent(self, _db: &dyn HirDatabase) -> DefWithBody {
+        self.parent.into()
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        let body = db.body(self.parent.into());
+        body[self.label_id].name.clone()
+    }
+
+    pub fn source(self, db: &dyn HirDatabase) -> InFile<ast::Label> {
+        let (_body, source_map) = db.body_with_source_map(self.parent.into());
+        let src = source_map.label_syntax(self.label_id);
+        let root = src.file_syntax(db.upcast());
+        src.map(|ast| ast.to_node(&root))
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum GenericParam {
+    TypeParam(TypeParam),
+    LifetimeParam(LifetimeParam),
+    ConstParam(ConstParam),
+}
+impl_from!(TypeParam, LifetimeParam, ConstParam for GenericParam);
+
+impl GenericParam {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            GenericParam::TypeParam(it) => it.module(db),
+            GenericParam::LifetimeParam(it) => it.module(db),
+            GenericParam::ConstParam(it) => it.module(db),
+        }
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        match self {
+            GenericParam::TypeParam(it) => it.name(db),
+            GenericParam::LifetimeParam(it) => it.name(db),
+            GenericParam::ConstParam(it) => it.name(db),
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct TypeParam {
+    pub(crate) id: TypeParamId,
+}
+
+impl TypeParam {
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        let params = db.generic_params(self.id.parent);
+        params.types[self.id.local_id].name.clone().unwrap_or_else(Name::missing)
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.id.parent.module(db.upcast()).into()
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let resolver = self.id.parent.resolver(db.upcast());
+        let krate = self.id.parent.module(db.upcast()).krate();
+        let ty = Ty::Placeholder(self.id);
+        Type::new_with_resolver_inner(db, krate, &resolver, ty)
+    }
+
+    pub fn trait_bounds(self, db: &dyn HirDatabase) -> Vec<Trait> {
+        db.generic_predicates_for_param(self.id)
+            .into_iter()
+            .filter_map(|pred| match &pred.value {
+                hir_ty::GenericPredicate::Implemented(trait_ref) => {
+                    Some(Trait::from(trait_ref.trait_))
+                }
+                _ => None,
+            })
+            .collect()
+    }
+
+    pub fn default(self, db: &dyn HirDatabase) -> Option<Type> {
+        let params = db.generic_defaults(self.id.parent);
+        let local_idx = hir_ty::param_idx(db, self.id)?;
+        let resolver = self.id.parent.resolver(db.upcast());
+        let krate = self.id.parent.module(db.upcast()).krate();
+        let ty = params.get(local_idx)?.clone();
+        let subst = Substs::type_params(db, self.id.parent);
+        let ty = ty.subst(&subst.prefix(local_idx));
+        Some(Type::new_with_resolver_inner(db, krate, &resolver, ty))
+    }
+}
+
+impl HirDisplay for TypeParam {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        write!(f, "{}", self.name(f.db))?;
+        let bounds = f.db.generic_predicates_for_param(self.id);
+        let substs = Substs::type_params(f.db, self.id.parent);
+        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
+        if !(predicates.is_empty() || f.omit_verbose_types()) {
+            write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;
+        }
+        Ok(())
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct LifetimeParam {
+    pub(crate) id: LifetimeParamId,
+}
+
+impl LifetimeParam {
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        let params = db.generic_params(self.id.parent);
+        params.lifetimes[self.id.local_id].name.clone()
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.id.parent.module(db.upcast()).into()
+    }
+
+    pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
+        self.id.parent.into()
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct ConstParam {
+    pub(crate) id: ConstParamId,
+}
+
+impl ConstParam {
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        let params = db.generic_params(self.id.parent);
+        params.consts[self.id.local_id].name.clone()
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.id.parent.module(db.upcast()).into()
+    }
+
+    pub fn parent(self, _db: &dyn HirDatabase) -> GenericDef {
+        self.id.parent.into()
+    }
+
+    pub fn ty(self, db: &dyn HirDatabase) -> Type {
+        let def = self.id.parent;
+        let krate = def.module(db.upcast()).krate();
+        Type::new(db, krate, def, db.const_param_ty(self.id))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Impl {
+    pub(crate) id: ImplId,
+}
+
+impl Impl {
+    pub fn all_in_crate(db: &dyn HirDatabase, krate: Crate) -> Vec<Impl> {
+        let inherent = db.inherent_impls_in_crate(krate.id);
+        let trait_ = db.trait_impls_in_crate(krate.id);
+
+        inherent.all_impls().chain(trait_.all_impls()).map(Self::from).collect()
+    }
+    pub fn for_trait(db: &dyn HirDatabase, krate: Crate, trait_: Trait) -> Vec<Impl> {
+        let impls = db.trait_impls_in_crate(krate.id);
+        impls.for_trait(trait_.id).map(Self::from).collect()
+    }
+
+    // FIXME: the return type is wrong. This should be a hir version of
+    // `TraitRef` (ie, resolved `TypeRef`).
+    pub fn target_trait(self, db: &dyn HirDatabase) -> Option<TypeRef> {
+        db.impl_data(self.id).target_trait.clone()
+    }
+
+    pub fn target_ty(self, db: &dyn HirDatabase) -> Type {
+        let impl_data = db.impl_data(self.id);
+        let resolver = self.id.resolver(db.upcast());
+        let krate = self.id.lookup(db.upcast()).container.krate();
+        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
+        let ty = Ty::from_hir(&ctx, &impl_data.target_type);
+        Type::new_with_resolver_inner(db, krate, &resolver, ty)
+    }
+
+    pub fn items(self, db: &dyn HirDatabase) -> Vec<AssocItem> {
+        db.impl_data(self.id).items.iter().map(|it| (*it).into()).collect()
+    }
+
+    pub fn is_negative(self, db: &dyn HirDatabase) -> bool {
+        db.impl_data(self.id).is_negative
+    }
+
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        self.id.lookup(db.upcast()).container.into()
+    }
+
+    pub fn krate(self, db: &dyn HirDatabase) -> Crate {
+        Crate { id: self.module(db).id.krate() }
+    }
+
+    pub fn is_builtin_derive(self, db: &dyn HirDatabase) -> Option<InFile<ast::Attr>> {
+        let src = self.source(db)?;
+        let item = src.file_id.is_builtin_derive(db.upcast())?;
+        let hygenic = hir_expand::hygiene::Hygiene::new(db.upcast(), item.file_id);
+
+        // FIXME: handle `cfg_attr`
+        let attr = item
+            .value
+            .attrs()
+            .filter_map(|it| {
+                let path = ModPath::from_src(it.path()?, &hygenic)?;
+                if path.as_ident()?.to_string() == "derive" {
+                    Some(it)
+                } else {
+                    None
+                }
+            })
+            .last()?;
+
+        Some(item.with_value(attr))
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Type {
+    krate: CrateId,
+    ty: InEnvironment<Ty>,
+}
+
+impl Type {
+    pub(crate) fn new_with_resolver(
+        db: &dyn HirDatabase,
+        resolver: &Resolver,
+        ty: Ty,
+    ) -> Option<Type> {
+        let krate = resolver.krate()?;
+        Some(Type::new_with_resolver_inner(db, krate, resolver, ty))
+    }
+    pub(crate) fn new_with_resolver_inner(
+        db: &dyn HirDatabase,
+        krate: CrateId,
+        resolver: &Resolver,
+        ty: Ty,
+    ) -> Type {
+        let environment = TraitEnvironment::lower(db, &resolver);
+        Type { krate, ty: InEnvironment { value: ty, environment } }
+    }
+
+    fn new(db: &dyn HirDatabase, krate: CrateId, lexical_env: impl HasResolver, ty: Ty) -> Type {
+        let resolver = lexical_env.resolver(db.upcast());
+        let environment = TraitEnvironment::lower(db, &resolver);
+        Type { krate, ty: InEnvironment { value: ty, environment } }
+    }
+
+    fn from_def(
+        db: &dyn HirDatabase,
+        krate: CrateId,
+        def: impl HasResolver + Into<TyDefId> + Into<GenericDefId>,
+    ) -> Type {
+        let substs = Substs::build_for_def(db, def).fill_with_unknown().build();
+        let ty = db.ty(def.into()).subst(&substs);
+        Type::new(db, krate, def, ty)
+    }
+
+    pub fn is_unit(&self) -> bool {
+        matches!(self.ty.value, Ty::Tuple(0, ..))
+    }
+    pub fn is_bool(&self) -> bool {
+        matches!(self.ty.value, Ty::Scalar(Scalar::Bool))
+    }
+
+    pub fn is_mutable_reference(&self) -> bool {
+        matches!(self.ty.value, Ty::Ref(hir_ty::Mutability::Mut, ..))
+    }
+
+    pub fn remove_ref(&self) -> Option<Type> {
+        match &self.ty.value {
+            Ty::Ref(.., substs) => Some(self.derived(substs[0].clone())),
+            _ => None,
+        }
+    }
+
+    pub fn is_unknown(&self) -> bool {
+        matches!(self.ty.value, Ty::Unknown)
+    }
+
+    /// Checks that particular type `ty` implements `std::future::Future`.
+    /// This function is used in `.await` syntax completion.
+    pub fn impls_future(&self, db: &dyn HirDatabase) -> bool {
+        // No special case for the type of async block, since Chalk can figure it out.
+
+        let krate = self.krate;
+
+        let std_future_trait =
+            db.lang_item(krate, "future_trait".into()).and_then(|it| it.as_trait());
+        let std_future_trait = match std_future_trait {
+            Some(it) => it,
+            None => return false,
+        };
+
+        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
+        method_resolution::implements_trait(
+            &canonical_ty,
+            db,
+            self.ty.environment.clone(),
+            krate,
+            std_future_trait,
+        )
+    }
+
+    /// Checks that particular type `ty` implements `std::ops::FnOnce`.
+    ///
+    /// This function can be used to check if a particular type is callable, since FnOnce is a
+    /// supertrait of Fn and FnMut, so all callable types implements at least FnOnce.
+    pub fn impls_fnonce(&self, db: &dyn HirDatabase) -> bool {
+        let krate = self.krate;
+
+        let fnonce_trait = match FnTrait::FnOnce.get_id(db, krate) {
+            Some(it) => it,
+            None => return false,
+        };
+
+        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
+        method_resolution::implements_trait_unique(
+            &canonical_ty,
+            db,
+            self.ty.environment.clone(),
+            krate,
+            fnonce_trait,
+        )
+    }
+
+    pub fn impls_trait(&self, db: &dyn HirDatabase, trait_: Trait, args: &[Type]) -> bool {
+        let trait_ref = hir_ty::TraitRef {
+            trait_: trait_.id,
+            substs: Substs::build_for_def(db, trait_.id)
+                .push(self.ty.value.clone())
+                .fill(args.iter().map(|t| t.ty.value.clone()))
+                .build(),
+        };
+
+        let goal = Canonical {
+            value: hir_ty::InEnvironment::new(
+                self.ty.environment.clone(),
+                hir_ty::Obligation::Trait(trait_ref),
+            ),
+            kinds: Arc::new([]),
+        };
+
+        db.trait_solve(self.krate, goal).is_some()
+    }
+
+    pub fn normalize_trait_assoc_type(
+        &self,
+        db: &dyn HirDatabase,
+        trait_: Trait,
+        args: &[Type],
+        alias: TypeAlias,
+    ) -> Option<Type> {
+        let subst = Substs::build_for_def(db, trait_.id)
+            .push(self.ty.value.clone())
+            .fill(args.iter().map(|t| t.ty.value.clone()))
+            .build();
+        let predicate = ProjectionPredicate {
+            projection_ty: ProjectionTy { associated_ty: alias.id, parameters: subst },
+            ty: Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)),
+        };
+        let goal = Canonical {
+            value: InEnvironment::new(
+                self.ty.environment.clone(),
+                Obligation::Projection(predicate),
+            ),
+            kinds: Arc::new([TyVariableKind::General]),
+        };
+
+        match db.trait_solve(self.krate, goal)? {
+            Solution::Unique(SolutionVariables(subst)) => {
+                subst.value.first().map(|ty| self.derived(ty.clone()))
+            }
+            Solution::Ambig(_) => None,
+        }
+    }
+
+    pub fn is_copy(&self, db: &dyn HirDatabase) -> bool {
+        let lang_item = db.lang_item(self.krate, SmolStr::new("copy"));
+        let copy_trait = match lang_item {
+            Some(LangItemTarget::TraitId(it)) => it,
+            _ => return false,
+        };
+        self.impls_trait(db, copy_trait.into(), &[])
+    }
+
+    pub fn as_callable(&self, db: &dyn HirDatabase) -> Option<Callable> {
+        let def = match self.ty.value {
+            Ty::FnDef(def, _) => Some(def),
+            _ => None,
+        };
+
+        let sig = self.ty.value.callable_sig(db)?;
+        Some(Callable { ty: self.clone(), sig, def, is_bound_method: false })
+    }
+
+    pub fn is_closure(&self) -> bool {
+        matches!(&self.ty.value, Ty::Closure { .. })
+    }
+
+    pub fn is_fn(&self) -> bool {
+        matches!(&self.ty.value, Ty::FnDef(..) | Ty::Function { .. })
+    }
+
+    pub fn is_packed(&self, db: &dyn HirDatabase) -> bool {
+        let adt_id = match self.ty.value {
+            Ty::Adt(hir_ty::AdtId(adt_id), ..) => adt_id,
+            _ => return false,
+        };
+
+        let adt = adt_id.into();
+        match adt {
+            Adt::Struct(s) => matches!(s.repr(db), Some(ReprKind::Packed)),
+            _ => false,
+        }
+    }
+
+    pub fn is_raw_ptr(&self) -> bool {
+        matches!(&self.ty.value, Ty::Raw(..))
+    }
+
+    pub fn contains_unknown(&self) -> bool {
+        return go(&self.ty.value);
+
+        fn go(ty: &Ty) -> bool {
+            match ty {
+                Ty::Unknown => true,
+                _ => ty.substs().map_or(false, |substs| substs.iter().any(go)),
+            }
+        }
+    }
+
+    pub fn fields(&self, db: &dyn HirDatabase) -> Vec<(Field, Type)> {
+        let (variant_id, substs) = match self.ty.value {
+            Ty::Adt(hir_ty::AdtId(AdtId::StructId(s)), ref substs) => (s.into(), substs),
+            Ty::Adt(hir_ty::AdtId(AdtId::UnionId(u)), ref substs) => (u.into(), substs),
+            _ => return Vec::new(),
+        };
+
+        db.field_types(variant_id)
+            .iter()
+            .map(|(local_id, ty)| {
+                let def = Field { parent: variant_id.into(), id: local_id };
+                let ty = ty.clone().subst(substs);
+                (def, self.derived(ty))
+            })
+            .collect()
+    }
+
+    pub fn tuple_fields(&self, _db: &dyn HirDatabase) -> Vec<Type> {
+        if let Ty::Tuple(_, substs) = &self.ty.value {
+            substs.iter().map(|ty| self.derived(ty.clone())).collect()
+        } else {
+            Vec::new()
+        }
+    }
+
+    pub fn autoderef<'a>(&'a self, db: &'a dyn HirDatabase) -> impl Iterator<Item = Type> + 'a {
+        // There should be no inference vars in types passed here
+        // FIXME check that?
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
+        let environment = self.ty.environment.clone();
+        let ty = InEnvironment { value: canonical, environment };
+        autoderef(db, Some(self.krate), ty)
+            .map(|canonical| canonical.value)
+            .map(move |ty| self.derived(ty))
+    }
+
+    // This would be nicer if it just returned an iterator, but that runs into
+    // lifetime problems, because we need to borrow temp `CrateImplDefs`.
+    pub fn iterate_assoc_items<T>(
+        self,
+        db: &dyn HirDatabase,
+        krate: Crate,
+        mut callback: impl FnMut(AssocItem) -> Option<T>,
+    ) -> Option<T> {
+        for krate in self.ty.value.def_crates(db, krate.id)? {
+            let impls = db.inherent_impls_in_crate(krate);
+
+            for impl_def in impls.for_self_ty(&self.ty.value) {
+                for &item in db.impl_data(*impl_def).items.iter() {
+                    if let Some(result) = callback(item.into()) {
+                        return Some(result);
+                    }
+                }
+            }
+        }
+        None
+    }
+
+    pub fn type_parameters(&self) -> impl Iterator<Item = Type> + '_ {
+        self.ty
+            .value
+            .strip_references()
+            .substs()
+            .into_iter()
+            .flat_map(|substs| substs.iter())
+            .map(move |ty| self.derived(ty.clone()))
+    }
+
+    pub fn iterate_method_candidates<T>(
+        &self,
+        db: &dyn HirDatabase,
+        krate: Crate,
+        traits_in_scope: &FxHashSet<TraitId>,
+        name: Option<&Name>,
+        mut callback: impl FnMut(&Ty, Function) -> Option<T>,
+    ) -> Option<T> {
+        // There should be no inference vars in types passed here
+        // FIXME check that?
+        // FIXME replace Unknown by bound vars here
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
+
+        let env = self.ty.environment.clone();
+        let krate = krate.id;
+
+        method_resolution::iterate_method_candidates(
+            &canonical,
+            db,
+            env,
+            krate,
+            traits_in_scope,
+            name,
+            method_resolution::LookupMode::MethodCall,
+            |ty, it| match it {
+                AssocItemId::FunctionId(f) => callback(ty, f.into()),
+                _ => None,
+            },
+        )
+    }
+
+    pub fn iterate_path_candidates<T>(
+        &self,
+        db: &dyn HirDatabase,
+        krate: Crate,
+        traits_in_scope: &FxHashSet<TraitId>,
+        name: Option<&Name>,
+        mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
+    ) -> Option<T> {
+        // There should be no inference vars in types passed here
+        // FIXME check that?
+        // FIXME replace Unknown by bound vars here
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
+
+        let env = self.ty.environment.clone();
+        let krate = krate.id;
+
+        method_resolution::iterate_method_candidates(
+            &canonical,
+            db,
+            env,
+            krate,
+            traits_in_scope,
+            name,
+            method_resolution::LookupMode::Path,
+            |ty, it| callback(ty, it.into()),
+        )
+    }
+
+    pub fn as_adt(&self) -> Option<Adt> {
+        let (adt, _subst) = self.ty.value.as_adt()?;
+        Some(adt.into())
+    }
+
+    pub fn as_dyn_trait(&self) -> Option<Trait> {
+        self.ty.value.dyn_trait().map(Into::into)
+    }
+
+    pub fn as_impl_traits(&self, db: &dyn HirDatabase) -> Option<Vec<Trait>> {
+        self.ty.value.impl_trait_bounds(db).map(|it| {
+            it.into_iter()
+                .filter_map(|pred| match pred {
+                    hir_ty::GenericPredicate::Implemented(trait_ref) => {
+                        Some(Trait::from(trait_ref.trait_))
+                    }
+                    _ => None,
+                })
+                .collect()
+        })
+    }
+
+    pub fn as_associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<Trait> {
+        self.ty.value.associated_type_parent_trait(db).map(Into::into)
+    }
+
+    // FIXME: provide required accessors such that it becomes implementable from outside.
+    pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
+        let rref = other.remove_ref();
+        self.ty.value.equals_ctor(rref.as_ref().map_or(&other.ty.value, |it| &it.ty.value))
+    }
+
+    fn derived(&self, ty: Ty) -> Type {
+        Type {
+            krate: self.krate,
+            ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
+        }
+    }
+
+    pub fn walk(&self, db: &dyn HirDatabase, mut cb: impl FnMut(Type)) {
+        // TypeWalk::walk for a Ty at first visits parameters and only after that the Ty itself.
+        // We need a different order here.
+
+        fn walk_substs(
+            db: &dyn HirDatabase,
+            type_: &Type,
+            substs: &Substs,
+            cb: &mut impl FnMut(Type),
+        ) {
+            for ty in substs.iter() {
+                walk_type(db, &type_.derived(ty.clone()), cb);
+            }
+        }
+
+        fn walk_bounds(
+            db: &dyn HirDatabase,
+            type_: &Type,
+            bounds: &[GenericPredicate],
+            cb: &mut impl FnMut(Type),
+        ) {
+            for pred in bounds {
+                match pred {
+                    GenericPredicate::Implemented(trait_ref) => {
+                        cb(type_.clone());
+                        walk_substs(db, type_, &trait_ref.substs, cb);
+                    }
+                    _ => (),
+                }
+            }
+        }
+
+        fn walk_type(db: &dyn HirDatabase, type_: &Type, cb: &mut impl FnMut(Type)) {
+            let ty = type_.ty.value.strip_references();
+            match ty {
+                Ty::Adt(..) => {
+                    cb(type_.derived(ty.clone()));
+                }
+                Ty::AssociatedType(..) => {
+                    if let Some(_) = ty.associated_type_parent_trait(db) {
+                        cb(type_.derived(ty.clone()));
+                    }
+                }
+                Ty::OpaqueType(..) => {
+                    if let Some(bounds) = ty.impl_trait_bounds(db) {
+                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
+                    }
+                }
+                Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
+                    if let Some(bounds) = ty.impl_trait_bounds(db) {
+                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
+                    }
+
+                    walk_substs(db, type_, &opaque_ty.parameters, cb);
+                }
+                Ty::Placeholder(_) => {
+                    if let Some(bounds) = ty.impl_trait_bounds(db) {
+                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
+                    }
+                }
+                Ty::Dyn(bounds) => {
+                    walk_bounds(db, &type_.derived(ty.clone()), bounds.as_ref(), cb);
+                }
+
+                _ => {}
+            }
+            if let Some(substs) = ty.substs() {
+                walk_substs(db, type_, &substs, cb);
+            }
+        }
+
+        walk_type(db, self, &mut cb);
+    }
+}
+
+impl HirDisplay for Type {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        self.ty.value.hir_fmt(f)
+    }
+}
+
+// FIXME: closures
+#[derive(Debug)]
+pub struct Callable {
+    ty: Type,
+    sig: CallableSig,
+    def: Option<CallableDefId>,
+    pub(crate) is_bound_method: bool,
+}
+
+pub enum CallableKind {
+    Function(Function),
+    TupleStruct(Struct),
+    TupleEnumVariant(Variant),
+    Closure,
+}
+
+impl Callable {
+    pub fn kind(&self) -> CallableKind {
+        match self.def {
+            Some(CallableDefId::FunctionId(it)) => CallableKind::Function(it.into()),
+            Some(CallableDefId::StructId(it)) => CallableKind::TupleStruct(it.into()),
+            Some(CallableDefId::EnumVariantId(it)) => CallableKind::TupleEnumVariant(it.into()),
+            None => CallableKind::Closure,
+        }
+    }
+    pub fn receiver_param(&self, db: &dyn HirDatabase) -> Option<ast::SelfParam> {
+        let func = match self.def {
+            Some(CallableDefId::FunctionId(it)) if self.is_bound_method => it,
+            _ => return None,
+        };
+        let src = func.lookup(db.upcast()).source(db.upcast());
+        let param_list = src.value.param_list()?;
+        param_list.self_param()
+    }
+    pub fn n_params(&self) -> usize {
+        self.sig.params().len() - if self.is_bound_method { 1 } else { 0 }
+    }
+    pub fn params(
+        &self,
+        db: &dyn HirDatabase,
+    ) -> Vec<(Option<Either<ast::SelfParam, ast::Pat>>, Type)> {
+        let types = self
+            .sig
+            .params()
+            .iter()
+            .skip(if self.is_bound_method { 1 } else { 0 })
+            .map(|ty| self.ty.derived(ty.clone()));
+        let patterns = match self.def {
+            Some(CallableDefId::FunctionId(func)) => {
+                let src = func.lookup(db.upcast()).source(db.upcast());
+                src.value.param_list().map(|param_list| {
+                    param_list
+                        .self_param()
+                        .map(|it| Some(Either::Left(it)))
+                        .filter(|_| !self.is_bound_method)
+                        .into_iter()
+                        .chain(param_list.params().map(|it| it.pat().map(Either::Right)))
+                })
+            }
+            _ => None,
+        };
+        patterns.into_iter().flatten().chain(iter::repeat(None)).zip(types).collect()
+    }
+    pub fn return_type(&self) -> Type {
+        self.ty.derived(self.sig.ret().clone())
+    }
+}
+
+/// For IDE only
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub enum ScopeDef {
+    ModuleDef(ModuleDef),
+    MacroDef(MacroDef),
+    GenericParam(GenericParam),
+    ImplSelfType(Impl),
+    AdtSelfType(Adt),
+    Local(Local),
+    Unknown,
+}
+
+impl ScopeDef {
+    pub fn all_items(def: PerNs) -> ArrayVec<[Self; 3]> {
+        let mut items = ArrayVec::new();
+
+        match (def.take_types(), def.take_values()) {
+            (Some(m1), None) => items.push(ScopeDef::ModuleDef(m1.into())),
+            (None, Some(m2)) => items.push(ScopeDef::ModuleDef(m2.into())),
+            (Some(m1), Some(m2)) => {
+                // Some items, like unit structs and enum variants, are
+                // returned as both a type and a value. Here we want
+                // to de-duplicate them.
+                if m1 != m2 {
+                    items.push(ScopeDef::ModuleDef(m1.into()));
+                    items.push(ScopeDef::ModuleDef(m2.into()));
+                } else {
+                    items.push(ScopeDef::ModuleDef(m1.into()));
+                }
+            }
+            (None, None) => {}
+        };
+
+        if let Some(macro_def_id) = def.take_macros() {
+            items.push(ScopeDef::MacroDef(macro_def_id.into()));
+        }
+
+        if items.is_empty() {
+            items.push(ScopeDef::Unknown);
+        }
+
+        items
+    }
+}
+
+impl From<ItemInNs> for ScopeDef {
+    fn from(item: ItemInNs) -> Self {
+        match item {
+            ItemInNs::Types(id) => ScopeDef::ModuleDef(id.into()),
+            ItemInNs::Values(id) => ScopeDef::ModuleDef(id.into()),
+            ItemInNs::Macros(id) => ScopeDef::MacroDef(id.into()),
+        }
+    }
+}
+
+pub trait HasVisibility {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility;
+    fn is_visible_from(&self, db: &dyn HirDatabase, module: Module) -> bool {
+        let vis = self.visibility(db);
+        vis.is_visible_from(db.upcast(), module.id)
+    }
+}
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 144851f83..945638cc5 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -20,12 +20,11 @@ use syntax::{
 };
 
 use crate::{
-    code_model::Access,
     db::HirDatabase,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, SourceAnalyzer},
-    AssocItem, Callable, ConstParam, Crate, Field, Function, HirFileId, Impl, InFile, Label,
-    LifetimeParam, Local, MacroDef, Module, ModuleDef, Name, Path, ScopeDef, Trait, Type,
+    Access, AssocItem, Callable, ConstParam, Crate, Field, Function, HirFileId, Impl, InFile,
+    Label, LifetimeParam, Local, MacroDef, Module, ModuleDef, Name, Path, ScopeDef, Trait, Type,
     TypeAlias, TypeParam, VariantDef,
 };
 
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 64ce4add1..d546512cb 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -28,9 +28,8 @@ use syntax::{
 };
 
 use crate::{
-    code_model::BuiltinType, db::HirDatabase, semantics::PathResolution, Adt, Const, Field,
-    Function, Local, MacroDef, ModuleDef, Static, Struct, Trait, Type, TypeAlias, TypeParam,
-    Variant,
+    db::HirDatabase, semantics::PathResolution, Adt, BuiltinType, Const, Field, Function, Local,
+    MacroDef, ModuleDef, Static, Struct, Trait, Type, TypeAlias, TypeParam, Variant,
 };
 use base_db::CrateId;
 
diff --git a/crates/hir_def/Cargo.toml b/crates/hir_def/Cargo.toml
index 535221294..c2d99280f 100644
--- a/crates/hir_def/Cargo.toml
+++ b/crates/hir_def/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 log = "0.4.8"
 once_cell = "1.3.1"
 rustc-hash = "1.1.0"
@@ -27,10 +28,10 @@ base_db = { path = "../base_db", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 hir_expand = { path = "../hir_expand", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 mbe = { path = "../mbe", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index ed36c3109..efbde17d8 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -21,8 +21,7 @@ use crate::{
     trace::Trace,
     type_ref::TypeRef,
     visibility::RawVisibility,
-    EnumId, HasModule, LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StructId, UnionId,
-    VariantId,
+    EnumId, LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StructId, UnionId, VariantId,
 };
 use cfg::CfgOptions;
 
@@ -92,10 +91,10 @@ fn parse_repr_tt(tt: &Subtree) -> Option<ReprKind> {
 impl StructData {
     pub(crate) fn struct_data_query(db: &dyn DefDatabase, id: StructId) -> Arc<StructData> {
         let loc = id.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let repr = repr_from_value(db, krate, &item_tree, ModItem::from(loc.id.value).into());
-        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+        let cfg_options = db.crate_graph()[loc.container.krate].cfg_options.clone();
 
         let strukt = &item_tree[loc.id.value];
         let variant_data = lower_fields(db, krate, &item_tree, &cfg_options, &strukt.fields, None);
@@ -107,10 +106,10 @@ impl StructData {
     }
     pub(crate) fn union_data_query(db: &dyn DefDatabase, id: UnionId) -> Arc<StructData> {
         let loc = id.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let repr = repr_from_value(db, krate, &item_tree, ModItem::from(loc.id.value).into());
-        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+        let cfg_options = db.crate_graph()[loc.container.krate].cfg_options.clone();
 
         let union = &item_tree[loc.id.value];
         let variant_data = lower_fields(db, krate, &item_tree, &cfg_options, &union.fields, None);
@@ -126,7 +125,7 @@ impl StructData {
 impl EnumData {
     pub(crate) fn enum_data_query(db: &dyn DefDatabase, e: EnumId) -> Arc<EnumData> {
         let loc = e.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let cfg_options = db.crate_graph()[krate].cfg_options.clone();
 
@@ -168,7 +167,7 @@ impl HasChildSource<LocalEnumVariantId> for EnumId {
     ) -> InFile<ArenaMap<LocalEnumVariantId, Self::Value>> {
         let src = self.lookup(db).source(db);
         let mut trace = Trace::new_for_map();
-        lower_enum(db, &mut trace, &src, self.lookup(db).container.module(db));
+        lower_enum(db, &mut trace, &src, self.lookup(db).container);
         src.with_value(trace.into_map())
     }
 }
@@ -238,10 +237,10 @@ impl HasChildSource<LocalFieldId> for VariantId {
                 // I don't really like the fact that we call into parent source
                 // here, this might add to more queries then necessary.
                 let src = it.parent.child_source(db);
-                (src.map(|map| map[it.local_id].kind()), it.parent.lookup(db).container.module(db))
+                (src.map(|map| map[it.local_id].kind()), it.parent.lookup(db).container)
             }
             VariantId::StructId(it) => {
-                (it.lookup(db).source(db).map(|it| it.kind()), it.lookup(db).container.module(db))
+                (it.lookup(db).source(db).map(|it| it.kind()), it.lookup(db).container)
             }
             VariantId::UnionId(it) => (
                 it.lookup(db).source(db).map(|it| {
@@ -249,7 +248,7 @@ impl HasChildSource<LocalFieldId> for VariantId {
                         .map(ast::StructKind::Record)
                         .unwrap_or(ast::StructKind::Unit)
                 }),
-                it.lookup(db).container.module(db),
+                it.lookup(db).container,
             ),
         };
         let mut expander = CfgExpander::new(db, src.file_id, module_id.krate);
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 24ffa6c3a..97cdbbb9e 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -13,7 +13,6 @@ use syntax::{
     ast::{self, AstNode, AttrsOwner},
     match_ast, AstToken, SmolStr, SyntaxNode,
 };
-use test_utils::mark;
 use tt::Subtree;
 
 use crate::{
@@ -177,7 +176,7 @@ impl RawAttrs {
                 if cfg_options.check(&cfg) == Some(false) {
                     None
                 } else {
-                    mark::hit!(cfg_attr_active);
+                    cov_mark::hit!(cfg_attr_active);
 
                     let attr = ast::Attr::parse(&format!("#[{}]", attr)).ok()?;
                     let hygiene = Hygiene::new_unhygienic(); // FIXME
@@ -268,7 +267,7 @@ impl Attrs {
         db: &dyn DefDatabase,
         e: EnumId,
     ) -> Arc<ArenaMap<LocalEnumVariantId, Attrs>> {
-        let krate = e.lookup(db).container.module(db).krate;
+        let krate = e.lookup(db).container.krate;
         let src = e.child_source(db);
         let mut res = ArenaMap::default();
 
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 16e1bac40..19c4eb521 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -20,7 +20,6 @@ use la_arena::{Arena, ArenaMap};
 use profile::Count;
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, AstPtr};
-use test_utils::mark;
 
 pub(crate) use lower::LowerCtx;
 
@@ -29,11 +28,10 @@ use crate::{
     db::DefDatabase,
     expr::{Expr, ExprId, Label, LabelId, Pat, PatId},
     item_scope::BuiltinShadowMode,
-    item_scope::ItemScope,
     nameres::DefMap,
     path::{ModPath, Path},
     src::HasSource,
-    AsMacroCall, DefWithBodyId, HasModule, LocalModuleId, Lookup, ModuleId,
+    AsMacroCall, BlockId, DefWithBodyId, HasModule, LocalModuleId, Lookup, ModuleId,
 };
 
 /// A subset of Expander that only deals with cfg attributes. We only need it to
@@ -105,7 +103,7 @@ impl Expander {
         macro_call: ast::MacroCall,
     ) -> ExpandResult<Option<(Mark, T)>> {
         if self.recursion_limit + 1 > EXPANSION_RECURSION_LIMIT {
-            mark::hit!(your_stack_belongs_to_me);
+            cov_mark::hit!(your_stack_belongs_to_me);
             return ExpandResult::str_err("reached recursion limit during macro expansion".into());
         }
 
@@ -227,7 +225,8 @@ pub struct Body {
     pub params: Vec<PatId>,
     /// The `ExprId` of the actual body expression.
     pub body_expr: ExprId,
-    pub item_scope: ItemScope,
+    /// Block expressions in this body that may contain inner items.
+    pub block_scopes: Vec<BlockId>,
     _c: Count<Self>,
 }
 
@@ -296,7 +295,7 @@ impl Body {
             }
         };
         let expander = Expander::new(db, file_id, module);
-        let (body, source_map) = Body::new(db, def, expander, params, body);
+        let (body, source_map) = Body::new(db, expander, params, body);
         (Arc::new(body), Arc::new(source_map))
     }
 
@@ -306,12 +305,11 @@ impl Body {
 
     fn new(
         db: &dyn DefDatabase,
-        def: DefWithBodyId,
         expander: Expander,
         params: Option<ast::ParamList>,
         body: Option<ast::Expr>,
     ) -> (Body, BodySourceMap) {
-        lower::lower(db, def, expander, params, body)
+        lower::lower(db, expander, params, body)
     }
 }
 
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index 40beb2f7a..8c8eb8007 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -1,17 +1,16 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
 
-use std::{any::type_name, mem, sync::Arc};
+use std::mem;
 
 use either::Either;
 use hir_expand::{
     hygiene::Hygiene,
     name::{name, AsName, Name},
-    ExpandError, HirFileId, MacroDefId, MacroDefKind,
+    ExpandError, HirFileId,
 };
 use la_arena::Arena;
 use profile::Count;
-use rustc_hash::FxHashMap;
 use syntax::{
     ast::{
         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
@@ -19,7 +18,6 @@ use syntax::{
     },
     AstNode, AstPtr, SyntaxNodePtr,
 };
-use test_utils::mark;
 
 use crate::{
     adt::StructKind,
@@ -33,11 +31,9 @@ use crate::{
         Statement,
     },
     item_scope::BuiltinShadowMode,
-    item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
-    AdtId, BlockLoc, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern,
-    ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    AdtId, BlockLoc, ModuleDefId,
 };
 
 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
@@ -61,15 +57,12 @@ impl LowerCtx {
 
 pub(super) fn lower(
     db: &dyn DefDatabase,
-    def: DefWithBodyId,
     expander: Expander,
     params: Option<ast::ParamList>,
     body: Option<ast::Expr>,
 ) -> (Body, BodySourceMap) {
-    let item_tree = db.item_tree(expander.current_file_id);
     ExprCollector {
         db,
-        def,
         source_map: BodySourceMap::default(),
         body: Body {
             exprs: Arena::default(),
@@ -77,14 +70,9 @@ pub(super) fn lower(
             labels: Arena::default(),
             params: Vec::new(),
             body_expr: dummy_expr_id(),
-            item_scope: Default::default(),
+            block_scopes: Vec::new(),
             _c: Count::new(),
         },
-        item_trees: {
-            let mut map = FxHashMap::default();
-            map.insert(expander.current_file_id, item_tree);
-            map
-        },
         expander,
     }
     .collect(params, body)
@@ -92,12 +80,9 @@ pub(super) fn lower(
 
 struct ExprCollector<'a> {
     db: &'a dyn DefDatabase,
-    def: DefWithBodyId,
     expander: Expander,
     body: Body,
     source_map: BodySourceMap,
-
-    item_trees: FxHashMap<HirFileId, Arc<ItemTree>>,
 }
 
 impl ExprCollector<'_> {
@@ -286,7 +271,7 @@ impl ExprCollector<'_> {
                         None => self.collect_expr_opt(condition.expr()),
                         // if let -- desugar to match
                         Some(pat) => {
-                            mark::hit!(infer_resolve_while_let);
+                            cov_mark::hit!(infer_resolve_while_let);
                             let pat = self.collect_pat(pat);
                             let match_expr = self.collect_expr_opt(condition.expr());
                             let placeholder_pat = self.missing_pat();
@@ -594,9 +579,6 @@ impl ExprCollector<'_> {
                 } else {
                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 
-                    let item_tree = self.db.item_tree(self.expander.current_file_id);
-                    self.item_trees.insert(self.expander.current_file_id, item_tree);
-
                     let id = collector(self, Some(expansion));
                     self.expander.exit(self.db, mark);
                     id
@@ -606,32 +588,6 @@ impl ExprCollector<'_> {
         }
     }
 
-    fn find_inner_item<N: ItemTreeNode>(&self, ast: &N::Source) -> Option<ItemTreeId<N>> {
-        let id = self.expander.ast_id(ast);
-        let tree = &self.item_trees[&id.file_id];
-
-        // FIXME: This probably breaks with `use` items, since they produce multiple item tree nodes
-
-        // Root file (non-macro).
-        let item_tree_id = tree
-            .all_inner_items()
-            .chain(tree.top_level_items().iter().copied())
-            .filter_map(|mod_item| mod_item.downcast::<N>())
-            .find(|tree_id| tree[*tree_id].ast_id().upcast() == id.value.upcast())
-            .or_else(|| {
-                log::debug!(
-                    "couldn't find inner {} item for {:?} (AST: `{}` - {:?})",
-                    type_name::<N>(),
-                    id,
-                    ast.syntax(),
-                    ast.syntax(),
-                );
-                None
-            })?;
-
-        Some(ItemTreeId::new(id.file_id, item_tree_id))
-    }
-
     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
         if let Some(expr) = expr {
             self.collect_expr(expr)
@@ -663,7 +619,6 @@ impl ExprCollector<'_> {
                             match expansion {
                                 Some(expansion) => {
                                     let statements: ast::MacroStmts = expansion;
-                                    this.collect_stmts_items(statements.statements());
 
                                     statements.statements().for_each(|stmt| {
                                         if let Some(mut r) = this.collect_stmt(stmt) {
@@ -701,6 +656,8 @@ impl ExprCollector<'_> {
         let block_loc =
             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
         let block_id = self.db.intern_block(block_loc);
+        self.body.block_scopes.push(block_id);
+
         let opt_def_map = self.db.block_def_map(block_id);
         let has_def_map = opt_def_map.is_some();
         let def_map = opt_def_map.unwrap_or_else(|| self.expander.def_map.clone());
@@ -708,7 +665,6 @@ impl ExprCollector<'_> {
         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
         let prev_local_module = mem::replace(&mut self.expander.module, module);
 
-        self.collect_stmts_items(block.statements());
         let statements =
             block.statements().filter_map(|s| self.collect_stmt(s)).flatten().collect();
         let tail = block.tail_expr().map(|e| self.collect_expr(e));
@@ -723,108 +679,6 @@ impl ExprCollector<'_> {
         expr_id
     }
 
-    fn collect_stmts_items(&mut self, stmts: ast::AstChildren<ast::Stmt>) {
-        let container = ContainerId::DefWithBodyId(self.def);
-
-        let items = stmts
-            .filter_map(|stmt| match stmt {
-                ast::Stmt::Item(it) => Some(it),
-                ast::Stmt::LetStmt(_) | ast::Stmt::ExprStmt(_) => None,
-            })
-            .filter_map(|item| {
-                let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
-                    ast::Item::Fn(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            FunctionLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::TypeAlias(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            TypeAliasLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::Const(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            ConstLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::Static(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (StaticLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Struct(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (StructLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Enum(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (EnumLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Union(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (UnionLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Trait(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (TraitLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::ExternBlock(_) => return None, // FIXME: collect from extern blocks
-                    ast::Item::Impl(_)
-                    | ast::Item::Use(_)
-                    | ast::Item::ExternCrate(_)
-                    | ast::Item::Module(_)
-                    | ast::Item::MacroCall(_) => return None,
-                    ast::Item::MacroRules(def) => {
-                        return Some(Either::Right(ast::Macro::from(def)));
-                    }
-                    ast::Item::MacroDef(def) => {
-                        return Some(Either::Right(ast::Macro::from(def)));
-                    }
-                };
-
-                Some(Either::Left((def, name)))
-            })
-            .collect::<Vec<_>>();
-
-        for either in items {
-            match either {
-                Either::Left((def, name)) => {
-                    self.body.item_scope.define_def(def);
-                    if let Some(name) = name {
-                        let vis = crate::visibility::Visibility::Public; // FIXME determine correctly
-                        let has_constructor = match def {
-                            ModuleDefId::AdtId(AdtId::StructId(s)) => {
-                                self.db.struct_data(s).variant_data.kind() != StructKind::Record
-                            }
-                            _ => true,
-                        };
-                        self.body.item_scope.push_res(
-                            name.as_name(),
-                            crate::per_ns::PerNs::from_def(def, vis, has_constructor),
-                        );
-                    }
-                }
-                Either::Right(e) => {
-                    let mac = MacroDefId {
-                        krate: self.expander.def_map.krate(),
-                        ast_id: Some(self.expander.ast_id(&e)),
-                        kind: MacroDefKind::Declarative,
-                        local_inner: false,
-                    };
-                    if let Some(name) = e.name() {
-                        self.body.item_scope.define_legacy_macro(name.as_name(), mac);
-                    }
-                }
-            }
-        }
-    }
-
     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
         if let Some(block) = expr {
             self.collect_block(block)
diff --git a/crates/hir_def/src/body/scope.rs b/crates/hir_def/src/body/scope.rs
index 210b4a617..1bbb54fc6 100644
--- a/crates/hir_def/src/body/scope.rs
+++ b/crates/hir_def/src/body/scope.rs
@@ -186,7 +186,7 @@ mod tests {
     use base_db::{fixture::WithFixture, FileId, SourceDatabase};
     use hir_expand::{name::AsName, InFile};
     use syntax::{algo::find_node_at_offset, ast, AstNode};
-    use test_utils::{assert_eq_text, extract_offset, mark};
+    use test_utils::{assert_eq_text, extract_offset};
 
     use crate::{db::DefDatabase, test_db::TestDB, FunctionId, ModuleDefId};
 
@@ -454,7 +454,7 @@ fn foo() {
 
     #[test]
     fn while_let_desugaring() {
-        mark::check!(infer_resolve_while_let);
+        cov_mark::check!(infer_resolve_while_let);
         do_check_local_name(
             r#"
 fn test() {
diff --git a/crates/hir_def/src/body/tests.rs b/crates/hir_def/src/body/tests.rs
index bb43569d7..991a32b15 100644
--- a/crates/hir_def/src/body/tests.rs
+++ b/crates/hir_def/src/body/tests.rs
@@ -2,7 +2,6 @@ mod block;
 
 use base_db::{fixture::WithFixture, SourceDatabase};
 use expect_test::Expect;
-use test_utils::mark;
 
 use crate::{test_db::TestDB, ModuleDefId};
 
@@ -48,7 +47,7 @@ fn check_at(ra_fixture: &str, expect: Expect) {
 
 #[test]
 fn your_stack_belongs_to_me() {
-    mark::check!(your_stack_belongs_to_me);
+    cov_mark::check!(your_stack_belongs_to_me);
     lower(
         "
 macro_rules! n_nuple {
diff --git a/crates/hir_def/src/body/tests/block.rs b/crates/hir_def/src/body/tests/block.rs
index 8bca72a17..3b6ba4cde 100644
--- a/crates/hir_def/src/body/tests/block.rs
+++ b/crates/hir_def/src/body/tests/block.rs
@@ -165,16 +165,16 @@ fn macro_resolve() {
     check_at(
         r#"
 //- /lib.rs crate:lib deps:core
-use core::mark;
+use core::cov_mark;
 
 fn f() {
     fn nested() {
-        mark::hit!(Hit);
+        cov_mark::hit!(Hit);
         $0
     }
 }
 //- /core.rs crate:core
-pub mod mark {
+pub mod cov_mark {
     #[macro_export]
     macro_rules! _hit {
         ($name:ident) => {
@@ -193,8 +193,8 @@ pub mod mark {
             nested: v
 
             crate
+            cov_mark: t
             f: v
-            mark: t
         "#]],
     );
 }
@@ -264,7 +264,7 @@ fn main() {
 fn underscore_import() {
     // This used to panic, because the default (private) visibility inside block expressions would
     // point into the containing `DefMap`, which visibilities should never be able to do.
-    mark::check!(adjust_vis_in_block_def_map);
+    cov_mark::check!(adjust_vis_in_block_def_map);
     check_at(
         r#"
 mod m {
diff --git a/crates/hir_def/src/child_by_source.rs b/crates/hir_def/src/child_by_source.rs
index 75c2d756b..2a331dcaf 100644
--- a/crates/hir_def/src/child_by_source.rs
+++ b/crates/hir_def/src/child_by_source.rs
@@ -17,13 +17,16 @@ use crate::{
 };
 
 pub trait ChildBySource {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap;
-}
-
-impl ChildBySource for TraitId {
     fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
         let mut res = DynMap::default();
+        self.child_by_source_to(db, &mut res);
+        res
+    }
+    fn child_by_source_to(&self, db: &dyn DefDatabase, map: &mut DynMap);
+}
 
+impl ChildBySource for TraitId {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let data = db.trait_data(*self);
         for (_name, item) in data.items.iter() {
             match *item {
@@ -41,15 +44,11 @@ impl ChildBySource for TraitId {
                 }
             }
         }
-
-        res
     }
 }
 
 impl ChildBySource for ImplId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let data = db.impl_data(*self);
         for &item in data.items.iter() {
             match item {
@@ -67,25 +66,21 @@ impl ChildBySource for ImplId {
                 }
             }
         }
-
-        res
     }
 }
 
 impl ChildBySource for ModuleId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let def_map = self.def_map(db);
         let module_data = &def_map[self.local_id];
-        module_data.scope.child_by_source(db)
+        module_data.scope.child_by_source_to(db, res);
     }
 }
 
 impl ChildBySource for ItemScope {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-        self.declarations().for_each(|item| add_module_def(db, &mut res, item));
-        self.impls().for_each(|imp| add_impl(db, &mut res, imp));
-        return res;
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
+        self.declarations().for_each(|item| add_module_def(db, res, item));
+        self.impls().for_each(|imp| add_impl(db, res, imp));
 
         fn add_module_def(db: &dyn DefDatabase, map: &mut DynMap, item: ModuleDefId) {
             match item {
@@ -134,9 +129,7 @@ impl ChildBySource for ItemScope {
 }
 
 impl ChildBySource for VariantId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let arena_map = self.child_source(db);
         let arena_map = arena_map.as_ref();
         for (local_id, source) in arena_map.value.iter() {
@@ -150,28 +143,27 @@ impl ChildBySource for VariantId {
                 }
             }
         }
-        res
     }
 }
 
 impl ChildBySource for EnumId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let arena_map = self.child_source(db);
         let arena_map = arena_map.as_ref();
         for (local_id, source) in arena_map.value.iter() {
             let id = EnumVariantId { parent: *self, local_id };
             res[keys::VARIANT].insert(arena_map.with_value(source.clone()), id)
         }
-
-        res
     }
 }
 
 impl ChildBySource for DefWithBodyId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let body = db.body(*self);
-        body.item_scope.child_by_source(db)
+        for def_map in body.block_scopes.iter().filter_map(|block| db.block_def_map(*block)) {
+            // All block expressions are merged into the same map, because they logically all add
+            // inner items to the containing `DefWithBodyId`.
+            def_map[def_map.root()].scope.child_by_source_to(db, res);
+        }
     }
 }
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index d3380e0f4..aea53d527 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -97,7 +97,7 @@ impl TraitData {
         let tr_def = &item_tree[tr_loc.id.value];
         let name = tr_def.name.clone();
         let auto = tr_def.auto;
-        let module_id = tr_loc.container.module(db);
+        let module_id = tr_loc.container;
         let container = AssocContainerId::TraitId(tr);
         let mut expander = Expander::new(db, tr_loc.id.file_id, module_id);
 
@@ -147,7 +147,7 @@ impl ImplData {
         let target_trait = impl_def.target_trait.map(|id| item_tree[id].clone());
         let target_type = item_tree[impl_def.target_type].clone();
         let is_negative = impl_def.is_negative;
-        let module_id = impl_loc.container.module(db);
+        let module_id = impl_loc.container;
         let container = AssocContainerId::ImplId(id);
         let mut expander = Expander::new(db, impl_loc.id.file_id, module_id);
 
diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index 3a98ffbaa..de08e2737 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -4,7 +4,6 @@ use std::iter;
 
 use hir_expand::name::{known, AsName, Name};
 use rustc_hash::FxHashSet;
-use test_utils::mark;
 
 use crate::nameres::DefMap;
 use crate::{
@@ -215,7 +214,7 @@ fn find_path_inner(
                     best_path_len - 1,
                     prefixed,
                 )?;
-                mark::hit!(partially_imported);
+                cov_mark::hit!(partially_imported);
                 path.push_segment(info.path.segments.last().unwrap().clone());
                 Some(path)
             })
@@ -235,7 +234,7 @@ fn find_path_inner(
     // that correctly (FIXME).
     if let Some(item_module) = item.as_module_def_id().and_then(|did| did.module(db)) {
         if item_module.def_map(db).block_id().is_some() && prefixed.is_some() {
-            mark::hit!(prefixed_in_block_expression);
+            cov_mark::hit!(prefixed_in_block_expression);
             prefixed = Some(PrefixKind::Plain);
         }
     }
@@ -252,18 +251,18 @@ fn find_path_inner(
 fn select_best_path(old_path: ModPath, new_path: ModPath, prefer_no_std: bool) -> ModPath {
     if old_path.starts_with_std() && new_path.can_start_with_std() {
         if prefer_no_std {
-            mark::hit!(prefer_no_std_paths);
+            cov_mark::hit!(prefer_no_std_paths);
             new_path
         } else {
-            mark::hit!(prefer_std_paths);
+            cov_mark::hit!(prefer_std_paths);
             old_path
         }
     } else if new_path.starts_with_std() && old_path.can_start_with_std() {
         if prefer_no_std {
-            mark::hit!(prefer_no_std_paths);
+            cov_mark::hit!(prefer_no_std_paths);
             old_path
         } else {
-            mark::hit!(prefer_std_paths);
+            cov_mark::hit!(prefer_std_paths);
             new_path
         }
     } else if new_path.len() < old_path.len() {
@@ -364,7 +363,6 @@ mod tests {
     use base_db::fixture::WithFixture;
     use hir_expand::hygiene::Hygiene;
     use syntax::ast::AstNode;
-    use test_utils::mark;
 
     use crate::test_db::TestDB;
 
@@ -522,7 +520,7 @@ mod tests {
 
     #[test]
     fn partially_imported() {
-        mark::check!(partially_imported);
+        cov_mark::check!(partially_imported);
         // Tests that short paths are used even for external items, when parts of the path are
         // already in scope.
         let code = r#"
@@ -686,7 +684,7 @@ mod tests {
 
     #[test]
     fn prefer_std_paths_over_alloc() {
-        mark::check!(prefer_std_paths);
+        cov_mark::check!(prefer_std_paths);
         let code = r#"
         //- /main.rs crate:main deps:alloc,std
         $0
@@ -712,7 +710,7 @@ mod tests {
 
     #[test]
     fn prefer_core_paths_over_std() {
-        mark::check!(prefer_no_std_paths);
+        cov_mark::check!(prefer_no_std_paths);
         let code = r#"
         //- /main.rs crate:main deps:core,std
         #![no_std]
@@ -842,7 +840,7 @@ mod tests {
 
     #[test]
     fn inner_items_from_inner_module() {
-        mark::check!(prefixed_in_block_expression);
+        cov_mark::check!(prefixed_in_block_expression);
         check_found_path(
             r#"
             fn main() {
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 3ace3be1f..a056ab797 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -421,8 +421,7 @@ impl HasChildSource<LocalConstParamId> for GenericDefId {
 }
 
 impl ChildBySource for GenericDefId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let (_, sm) = GenericParams::new(db, *self);
 
         let sm = sm.as_ref();
@@ -440,6 +439,5 @@ impl ChildBySource for GenericDefId {
             let id = ConstParamId { parent: *self, local_id };
             res[keys::CONST_PARAM].insert(sm.with_value(src.clone()), id);
         }
-        res
     }
 }
diff --git a/crates/hir_def/src/import_map.rs b/crates/hir_def/src/import_map.rs
index 0a3dc7956..369bc3350 100644
--- a/crates/hir_def/src/import_map.rs
+++ b/crates/hir_def/src/import_map.rs
@@ -8,7 +8,6 @@ use hir_expand::name::Name;
 use indexmap::{map::Entry, IndexMap};
 use itertools::Itertools;
 use rustc_hash::{FxHashSet, FxHasher};
-use test_utils::mark;
 
 use crate::{
     db::DefDatabase, item_scope::ItemInNs, visibility::Visibility, AssocItemId, ModuleDefId,
@@ -193,7 +192,7 @@ impl ImportMap {
                 // cannot use associated type aliases directly: need a `<Struct as Trait>::TypeAlias`
                 // qualifier, ergo no need to store it for imports in import_map
                 AssocItemId::TypeAliasId(_) => {
-                    mark::hit!(type_aliases_ignored);
+                    cov_mark::hit!(type_aliases_ignored);
                     continue;
                 }
             };
@@ -388,7 +387,7 @@ pub fn search_dependencies<'a>(
     db: &'a dyn DefDatabase,
     krate: CrateId,
     query: Query,
-) -> Vec<ItemInNs> {
+) -> FxHashSet<ItemInNs> {
     let _p = profile::span("search_dependencies").detail(|| format!("{:?}", query));
 
     let graph = db.crate_graph();
@@ -403,41 +402,42 @@ pub fn search_dependencies<'a>(
     }
 
     let mut stream = op.union();
-    let mut res = Vec::new();
+
+    let mut all_indexed_values = FxHashSet::default();
     while let Some((_, indexed_values)) = stream.next() {
-        for indexed_value in indexed_values {
-            let import_map = &import_maps[indexed_value.index];
-            let importables = &import_map.importables[indexed_value.value as usize..];
+        all_indexed_values.extend(indexed_values.iter().copied());
+    }
 
-            let common_importable_data = &import_map.map[&importables[0]];
-            if !query.import_matches(common_importable_data, true) {
-                continue;
-            }
+    let mut res = FxHashSet::default();
+    for indexed_value in all_indexed_values {
+        let import_map = &import_maps[indexed_value.index];
+        let importables = &import_map.importables[indexed_value.value as usize..];
 
-            // Path shared by the importable items in this group.
-            let common_importables_path_fst = fst_path(&common_importable_data.path);
-            // Add the items from this `ModPath` group. Those are all subsequent items in
-            // `importables` whose paths match `path`.
-            let iter = importables
-                .iter()
-                .copied()
-                .take_while(|item| {
-                    common_importables_path_fst == fst_path(&import_map.map[item].path)
-                })
-                .filter(|&item| match item_import_kind(item) {
-                    Some(import_kind) => !query.exclude_import_kinds.contains(&import_kind),
-                    None => true,
-                })
-                .filter(|item| {
-                    !query.case_sensitive // we've already checked the common importables path case-insensitively
+        let common_importable_data = &import_map.map[&importables[0]];
+        if !query.import_matches(common_importable_data, true) {
+            continue;
+        }
+
+        // Path shared by the importable items in this group.
+        let common_importables_path_fst = fst_path(&common_importable_data.path);
+        // Add the items from this `ModPath` group. Those are all subsequent items in
+        // `importables` whose paths match `path`.
+        let iter = importables
+            .iter()
+            .copied()
+            .take_while(|item| common_importables_path_fst == fst_path(&import_map.map[item].path))
+            .filter(|&item| match item_import_kind(item) {
+                Some(import_kind) => !query.exclude_import_kinds.contains(&import_kind),
+                None => true,
+            })
+            .filter(|item| {
+                !query.case_sensitive // we've already checked the common importables path case-insensitively
                         || query.import_matches(&import_map.map[item], false)
-                });
-            res.extend(iter);
+            });
+        res.extend(iter);
 
-            if res.len() >= query.limit {
-                res.truncate(query.limit);
-                return res;
-            }
+        if res.len() >= query.limit {
+            return res;
         }
     }
 
@@ -462,7 +462,6 @@ fn item_import_kind(item: ItemInNs) -> Option<ImportKind> {
 mod tests {
     use base_db::{fixture::WithFixture, SourceDatabase, Upcast};
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{test_db::TestDB, AssocContainerId, Lookup};
 
@@ -800,7 +799,7 @@ mod tests {
 
     #[test]
     fn fuzzy_import_trait_and_assoc_items() {
-        mark::check!(type_aliases_ignored);
+        cov_mark::check!(type_aliases_ignored);
         let ra_fixture = r#"
         //- /main.rs crate:main deps:dep
         //- /dep.rs crate:dep
@@ -821,10 +820,10 @@ mod tests {
             Query::new("fmt".to_string()).search_mode(SearchMode::Fuzzy),
             expect![[r#"
                 dep::fmt (t)
+                dep::fmt::Display::format_method (a)
                 dep::fmt::Display (t)
                 dep::fmt::Display::FMT_CONST (a)
                 dep::fmt::Display::format_function (a)
-                dep::fmt::Display::format_method (a)
             "#]],
         );
     }
@@ -850,9 +849,9 @@ mod tests {
             "main",
             Query::new("fmt".to_string()).search_mode(SearchMode::Fuzzy).assoc_items_only(),
             expect![[r#"
+            dep::fmt::Display::format_method (a)
             dep::fmt::Display::FMT_CONST (a)
             dep::fmt::Display::format_function (a)
-            dep::fmt::Display::format_method (a)
         "#]],
         );
 
@@ -911,12 +910,12 @@ mod tests {
             Query::new("fmt".to_string()).search_mode(SearchMode::Fuzzy),
             expect![[r#"
                 dep::fmt (t)
-                dep::Fmt (t)
+                dep::format (f)
                 dep::Fmt (v)
-                dep::Fmt (m)
                 dep::fmt::Display (t)
+                dep::Fmt (t)
                 dep::fmt::Display::fmt (a)
-                dep::format (f)
+                dep::Fmt (m)
             "#]],
         );
 
@@ -926,10 +925,10 @@ mod tests {
             Query::new("fmt".to_string()).search_mode(SearchMode::Equals),
             expect![[r#"
                 dep::fmt (t)
-                dep::Fmt (t)
                 dep::Fmt (v)
-                dep::Fmt (m)
+                dep::Fmt (t)
                 dep::fmt::Display::fmt (a)
+                dep::Fmt (m)
             "#]],
         );
 
@@ -939,11 +938,11 @@ mod tests {
             Query::new("fmt".to_string()).search_mode(SearchMode::Contains),
             expect![[r#"
                 dep::fmt (t)
-                dep::Fmt (t)
                 dep::Fmt (v)
-                dep::Fmt (m)
                 dep::fmt::Display (t)
+                dep::Fmt (t)
                 dep::fmt::Display::fmt (a)
+                dep::Fmt (m)
             "#]],
         );
     }
@@ -980,11 +979,11 @@ mod tests {
             Query::new("fmt".to_string()),
             expect![[r#"
                 dep::fmt (t)
-                dep::Fmt (t)
                 dep::Fmt (v)
-                dep::Fmt (m)
                 dep::fmt::Display (t)
+                dep::Fmt (t)
                 dep::fmt::Display::fmt (a)
+                dep::Fmt (m)
             "#]],
         );
 
@@ -994,10 +993,10 @@ mod tests {
             Query::new("fmt".to_string()).name_only(),
             expect![[r#"
                 dep::fmt (t)
-                dep::Fmt (t)
                 dep::Fmt (v)
-                dep::Fmt (m)
+                dep::Fmt (t)
                 dep::fmt::Display::fmt (a)
+                dep::Fmt (m)
             "#]],
         );
     }
@@ -1018,9 +1017,9 @@ mod tests {
             Query::new("FMT".to_string()),
             expect![[r#"
                 dep::fmt (t)
+                dep::FMT (v)
                 dep::fmt (v)
                 dep::FMT (t)
-                dep::FMT (v)
             "#]],
         );
 
@@ -1060,6 +1059,8 @@ mod tests {
             expect![[r#"
                 dep::fmt (t)
                 dep::Fmt (t)
+                dep::Fmt (m)
+                dep::Fmt (v)
             "#]],
         );
     }
@@ -1080,9 +1081,9 @@ mod tests {
             Query::new("FMT".to_string()),
             expect![[r#"
                 dep::fmt (t)
+                dep::FMT (v)
                 dep::fmt (v)
                 dep::FMT (t)
-                dep::FMT (v)
             "#]],
         );
 
diff --git a/crates/hir_def/src/item_scope.rs b/crates/hir_def/src/item_scope.rs
index 4e5daa2ff..aafd73b60 100644
--- a/crates/hir_def/src/item_scope.rs
+++ b/crates/hir_def/src/item_scope.rs
@@ -9,7 +9,6 @@ use hir_expand::MacroDefKind;
 use once_cell::sync::Lazy;
 use rustc_hash::{FxHashMap, FxHashSet};
 use stdx::format_to;
-use test_utils::mark;
 
 use crate::{
     db::DefDatabase, per_ns::PerNs, visibility::Visibility, AdtId, BuiltinType, ImplId,
@@ -169,37 +168,6 @@ impl ItemScope {
         self.unnamed_trait_imports.insert(tr, vis);
     }
 
-    pub(crate) fn push_res(&mut self, name: Name, def: PerNs) -> bool {
-        let mut changed = false;
-
-        if let Some(types) = def.types {
-            self.types.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                types
-            });
-        }
-        if let Some(values) = def.values {
-            self.values.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                values
-            });
-        }
-        if let Some(macros) = def.macros {
-            self.macros.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                macros
-            });
-        }
-
-        if def.is_none() {
-            if self.unresolved.insert(name) {
-                changed = true;
-            }
-        }
-
-        changed
-    }
-
     pub(crate) fn push_res_with_import(
         &mut self,
         glob_imports: &mut PerNsGlobImports,
@@ -237,7 +205,7 @@ impl ItemScope {
                         if $glob_imports.$field.contains(&$lookup)
                             && matches!($def_import_type, ImportType::Named) =>
                     {
-                        mark::hit!(import_shadowed);
+                        cov_mark::hit!(import_shadowed);
                         $glob_imports.$field.remove(&$lookup);
                         if let Some(fld) = $def.$field {
                             entry.insert(fld);
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 3233b1957..09bcb10dc 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -25,7 +25,6 @@ use profile::Count;
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use syntax::{ast, match_ast, SyntaxKind};
-use test_utils::mark;
 
 use crate::{
     attr::{Attrs, RawAttrs},
@@ -210,18 +209,6 @@ impl ItemTree {
         }
     }
 
-    pub fn source<S: ItemTreeNode>(&self, db: &dyn DefDatabase, of: ItemTreeId<S>) -> S::Source {
-        // This unwrap cannot fail, since it has either succeeded above, or resulted in an empty
-        // ItemTree (in which case there is no valid `FileItemTreeId` to call this method with).
-        let root =
-            db.parse_or_expand(of.file_id).expect("parse_or_expand failed on constructed ItemTree");
-
-        let id = self[of.value].ast_id();
-        let map = db.ast_id_map(of.file_id);
-        let ptr = map.get(id);
-        ptr.to_node(&root)
-    }
-
     fn data(&self) -> &ItemTreeData {
         self.data.as_ref().expect("attempted to access data of empty ItemTree")
     }
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 8f2f0b340..240fdacf9 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -466,7 +466,7 @@ impl Ctx {
                             .collect()
                     })
                     .unwrap_or_else(|| {
-                        mark::hit!(name_res_works_for_broken_modules);
+                        cov_mark::hit!(name_res_works_for_broken_modules);
                         Box::new([]) as Box<[_]>
                     }),
             }
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index 4498d94bb..6d11c5be4 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -108,7 +108,7 @@ pub type LocalModuleId = Idx<nameres::ModuleData>;
 
 #[derive(Debug)]
 pub struct ItemLoc<N: ItemTreeNode> {
-    pub container: ContainerId,
+    pub container: ModuleId,
     pub id: ItemTreeId<N>,
 }
 
@@ -279,18 +279,12 @@ pub struct ConstParamId {
 pub type LocalConstParamId = Idx<generics::ConstParamData>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum ContainerId {
-    ModuleId(ModuleId),
-    DefWithBodyId(DefWithBodyId),
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum AssocContainerId {
-    ContainerId(ContainerId),
+    ModuleId(ModuleId),
     ImplId(ImplId),
     TraitId(TraitId),
 }
-impl_from!(ContainerId for AssocContainerId);
+impl_from!(ModuleId for AssocContainerId);
 
 /// A Data Type
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -447,21 +441,12 @@ pub trait HasModule {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId;
 }
 
-impl HasModule for ContainerId {
-    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
-        match *self {
-            ContainerId::ModuleId(it) => it,
-            ContainerId::DefWithBodyId(it) => it.module(db),
-        }
-    }
-}
-
 impl HasModule for AssocContainerId {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         match *self {
-            AssocContainerId::ContainerId(it) => it.module(db),
-            AssocContainerId::ImplId(it) => it.lookup(db).container.module(db),
-            AssocContainerId::TraitId(it) => it.lookup(db).container.module(db),
+            AssocContainerId::ModuleId(it) => it,
+            AssocContainerId::ImplId(it) => it.lookup(db).container,
+            AssocContainerId::TraitId(it) => it.lookup(db).container,
         }
     }
 }
@@ -479,16 +464,15 @@ impl HasModule for AdtId {
             AdtId::UnionId(it) => it.lookup(db).container,
             AdtId::EnumId(it) => it.lookup(db).container,
         }
-        .module(db)
     }
 }
 
 impl HasModule for VariantId {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         match self {
-            VariantId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
-            VariantId::StructId(it) => it.lookup(db).container.module(db),
-            VariantId::UnionId(it) => it.lookup(db).container.module(db),
+            VariantId::EnumVariantId(it) => it.parent.lookup(db).container,
+            VariantId::StructId(it) => it.lookup(db).container,
+            VariantId::UnionId(it) => it.lookup(db).container,
         }
     }
 }
@@ -518,18 +502,18 @@ impl HasModule for GenericDefId {
         match self {
             GenericDefId::FunctionId(it) => it.lookup(db).module(db),
             GenericDefId::AdtId(it) => it.module(db),
-            GenericDefId::TraitId(it) => it.lookup(db).container.module(db),
+            GenericDefId::TraitId(it) => it.lookup(db).container,
             GenericDefId::TypeAliasId(it) => it.lookup(db).module(db),
-            GenericDefId::ImplId(it) => it.lookup(db).container.module(db),
-            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
+            GenericDefId::ImplId(it) => it.lookup(db).container,
+            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container,
             GenericDefId::ConstId(it) => it.lookup(db).module(db),
         }
     }
 }
 
 impl HasModule for StaticLoc {
-    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
-        self.container.module(db)
+    fn module(&self, _db: &dyn db::DefDatabase) -> ModuleId {
+        self.container
     }
 }
 
@@ -542,10 +526,10 @@ impl ModuleDefId {
             ModuleDefId::ModuleId(id) => *id,
             ModuleDefId::FunctionId(id) => id.lookup(db).module(db),
             ModuleDefId::AdtId(id) => id.module(db),
-            ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container.module(db),
+            ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container,
             ModuleDefId::ConstId(id) => id.lookup(db).container.module(db),
-            ModuleDefId::StaticId(id) => id.lookup(db).container.module(db),
-            ModuleDefId::TraitId(id) => id.lookup(db).container.module(db),
+            ModuleDefId::StaticId(id) => id.lookup(db).container,
+            ModuleDefId::TraitId(id) => id.lookup(db).container,
             ModuleDefId::TypeAliasId(id) => id.lookup(db).module(db),
             ModuleDefId::BuiltinType(_) => return None,
         })
@@ -559,12 +543,12 @@ impl AttrDefId {
             AttrDefId::FieldId(it) => it.parent.module(db).krate,
             AttrDefId::AdtId(it) => it.module(db).krate,
             AttrDefId::FunctionId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db).krate,
+            AttrDefId::EnumVariantId(it) => it.parent.lookup(db).container.krate,
             AttrDefId::StaticId(it) => it.lookup(db).module(db).krate,
             AttrDefId::ConstId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::TraitId(it) => it.lookup(db).container.module(db).krate,
+            AttrDefId::TraitId(it) => it.lookup(db).container.krate,
             AttrDefId::TypeAliasId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::ImplId(it) => it.lookup(db).container.module(db).krate,
+            AttrDefId::ImplId(it) => it.lookup(db).container.krate,
             AttrDefId::GenericParamId(it) => {
                 match it {
                     GenericParamId::TypeParamId(it) => it.parent,
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index e51d89b43..9ed48c506 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -18,7 +18,6 @@ use hir_expand::{
 use hir_expand::{InFile, MacroCallLoc};
 use rustc_hash::{FxHashMap, FxHashSet};
 use syntax::ast;
-use test_utils::mark;
 use tt::{Leaf, TokenTree};
 
 use crate::{
@@ -38,9 +37,9 @@ use crate::{
     path::{ImportAlias, ModPath, PathKind},
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
-    AdtId, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc,
-    ImplLoc, Intern, LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc,
-    UnionLoc, UnresolvedMacro,
+    AdtId, AstId, AstIdWithPath, ConstLoc, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
+    LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    UnresolvedMacro,
 };
 
 const GLOB_RECURSION_LIMIT: usize = 100;
@@ -462,7 +461,7 @@ impl DefCollector<'_> {
         let res = self.def_map.resolve_name_in_extern_prelude(&extern_crate.name);
 
         if let Some(ModuleDefId::ModuleId(m)) = res.take_types() {
-            mark::hit!(macro_rules_from_other_crates_are_visible_with_macro_use);
+            cov_mark::hit!(macro_rules_from_other_crates_are_visible_with_macro_use);
             self.import_all_macros_exported(current_module_id, m.krate);
         }
     }
@@ -571,10 +570,10 @@ impl DefCollector<'_> {
             match def.take_types() {
                 Some(ModuleDefId::ModuleId(m)) => {
                     if import.is_prelude {
-                        mark::hit!(std_prelude);
+                        cov_mark::hit!(std_prelude);
                         self.def_map.prelude = Some(m);
                     } else if m.krate != self.def_map.krate {
-                        mark::hit!(glob_across_crates);
+                        cov_mark::hit!(glob_across_crates);
                         // glob import from other crate => we can just import everything once
                         let item_map = m.def_map(self.db);
                         let scope = &item_map[m.local_id].scope;
@@ -626,7 +625,7 @@ impl DefCollector<'_> {
                     }
                 }
                 Some(ModuleDefId::AdtId(AdtId::EnumId(e))) => {
-                    mark::hit!(glob_enum);
+                    cov_mark::hit!(glob_enum);
                     // glob import from enum => just import all the variants
 
                     // XXX: urgh, so this works by accident! Here, we look at
@@ -675,7 +674,7 @@ impl DefCollector<'_> {
 
                     self.update(module_id, &[(name, def)], vis, ImportType::Named);
                 }
-                None => mark::hit!(bogus_paths),
+                None => cov_mark::hit!(bogus_paths),
             }
         }
     }
@@ -738,7 +737,7 @@ impl DefCollector<'_> {
                             if max_vis == old_vis {
                                 false
                             } else {
-                                mark::hit!(upgrade_underscore_visibility);
+                                cov_mark::hit!(upgrade_underscore_visibility);
                                 true
                             }
                         }
@@ -866,7 +865,7 @@ impl DefCollector<'_> {
         depth: usize,
     ) {
         if depth > EXPANSION_DEPTH_LIMIT {
-            mark::hit!(macro_expansion_overflow);
+            cov_mark::hit!(macro_expansion_overflow);
             log::warn!("macro expansion is too deep");
             return;
         }
@@ -1009,7 +1008,7 @@ impl ModCollector<'_, '_> {
         // Prelude module is always considered to be `#[macro_use]`.
         if let Some(prelude_module) = self.def_collector.def_map.prelude {
             if prelude_module.krate != self.def_collector.def_map.krate {
-                mark::hit!(prelude_is_macro_use);
+                cov_mark::hit!(prelude_is_macro_use);
                 self.def_collector.import_all_macros_exported(self.module_id, prelude_module.krate);
             }
         }
@@ -1043,7 +1042,6 @@ impl ModCollector<'_, '_> {
                 }
             }
             let module = self.def_collector.def_map.module_id(self.module_id);
-            let container = ContainerId::ModuleId(module);
 
             let mut def = None;
             match item {
@@ -1110,9 +1108,9 @@ impl ModCollector<'_, '_> {
                 }
                 ModItem::Impl(imp) => {
                     let module = self.def_collector.def_map.module_id(self.module_id);
-                    let container = ContainerId::ModuleId(module);
-                    let impl_id = ImplLoc { container, id: ItemTreeId::new(self.file_id, imp) }
-                        .intern(self.def_collector.db);
+                    let impl_id =
+                        ImplLoc { container: module, id: ItemTreeId::new(self.file_id, imp) }
+                            .intern(self.def_collector.db);
                     self.def_collector.def_map.modules[self.module_id].scope.define_impl(impl_id)
                 }
                 ModItem::Function(id) => {
@@ -1122,7 +1120,7 @@ impl ModCollector<'_, '_> {
 
                     def = Some(DefData {
                         id: FunctionLoc {
-                            container: container.into(),
+                            container: module.into(),
                             id: ItemTreeId::new(self.file_id, id),
                         }
                         .intern(self.def_collector.db)
@@ -1141,7 +1139,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: StructLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: StructLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1158,7 +1156,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: UnionLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: UnionLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1175,7 +1173,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: EnumLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: EnumLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1189,7 +1187,7 @@ impl ModCollector<'_, '_> {
                     if let Some(name) = &it.name {
                         def = Some(DefData {
                             id: ConstLoc {
-                                container: container.into(),
+                                container: module.into(),
                                 id: ItemTreeId::new(self.file_id, id),
                             }
                             .intern(self.def_collector.db)
@@ -1204,7 +1202,7 @@ impl ModCollector<'_, '_> {
                     let it = &self.item_tree[id];
 
                     def = Some(DefData {
-                        id: StaticLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: StaticLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1216,7 +1214,7 @@ impl ModCollector<'_, '_> {
                     let it = &self.item_tree[id];
 
                     def = Some(DefData {
-                        id: TraitLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: TraitLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1229,7 +1227,7 @@ impl ModCollector<'_, '_> {
 
                     def = Some(DefData {
                         id: TypeAliasLoc {
-                            container: container.into(),
+                            container: module.into(),
                             id: ItemTreeId::new(self.file_id, id),
                         }
                         .intern(self.def_collector.db)
diff --git a/crates/hir_def/src/nameres/mod_resolution.rs b/crates/hir_def/src/nameres/mod_resolution.rs
index af3262439..d5de9899c 100644
--- a/crates/hir_def/src/nameres/mod_resolution.rs
+++ b/crates/hir_def/src/nameres/mod_resolution.rs
@@ -2,7 +2,6 @@
 use base_db::{AnchoredPath, FileId};
 use hir_expand::name::Name;
 use syntax::SmolStr;
-use test_utils::mark;
 
 use crate::{db::DefDatabase, HirFileId};
 
@@ -28,7 +27,7 @@ impl ModDir {
         let depth = self.depth + 1;
         if depth > MOD_DEPTH_LIMIT {
             log::error!("MOD_DEPTH_LIMIT exceeded");
-            mark::hit!(circular_mods);
+            cov_mark::hit!(circular_mods);
             return None;
         }
         Some(ModDir { dir_path, root_non_dir_owner, depth })
diff --git a/crates/hir_def/src/nameres/path_resolution.rs b/crates/hir_def/src/nameres/path_resolution.rs
index dd1db0094..db459b1ed 100644
--- a/crates/hir_def/src/nameres/path_resolution.rs
+++ b/crates/hir_def/src/nameres/path_resolution.rs
@@ -13,7 +13,6 @@
 use base_db::Edition;
 use hir_expand::name;
 use hir_expand::name::Name;
-use test_utils::mark;
 
 use crate::{
     db::DefDatabase,
@@ -63,7 +62,7 @@ impl ResolvePathResult {
 impl DefMap {
     pub(super) fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs {
         if name == &name!(self) {
-            mark::hit!(extern_crate_self_as);
+            cov_mark::hit!(extern_crate_self_as);
             return PerNs::types(self.module_id(self.root).into(), Visibility::Public);
         }
         self.extern_prelude
@@ -101,7 +100,7 @@ impl DefMap {
         // DefMap they're written in, so we restrict them when that happens.
         if let Visibility::Module(m) = vis {
             if self.block_id() != m.block {
-                mark::hit!(adjust_vis_in_block_def_map);
+                cov_mark::hit!(adjust_vis_in_block_def_map);
                 vis = Visibility::Module(self.module_id(self.root()));
                 log::debug!("visibility {:?} points outside DefMap, adjusting to {:?}", m, vis);
             }
@@ -157,7 +156,7 @@ impl DefMap {
         }
     }
 
-    pub(super) fn resolve_path_fp_with_macro_single(
+    fn resolve_path_fp_with_macro_single(
         &self,
         db: &dyn DefDatabase,
         mode: ResolveMode,
@@ -169,12 +168,12 @@ impl DefMap {
         let mut curr_per_ns: PerNs = match path.kind {
             PathKind::DollarCrate(krate) => {
                 if krate == self.krate {
-                    mark::hit!(macro_dollar_crate_self);
+                    cov_mark::hit!(macro_dollar_crate_self);
                     PerNs::types(self.crate_root(db).into(), Visibility::Public)
                 } else {
                     let def_map = db.crate_def_map(krate);
                     let module = def_map.module_id(def_map.root);
-                    mark::hit!(macro_dollar_crate_other);
+                    cov_mark::hit!(macro_dollar_crate_other);
                     PerNs::types(module.into(), Visibility::Public)
                 }
             }
@@ -310,7 +309,7 @@ impl DefMap {
                 }
                 ModuleDefId::AdtId(AdtId::EnumId(e)) => {
                     // enum variant
-                    mark::hit!(can_import_enum_variant);
+                    cov_mark::hit!(can_import_enum_variant);
                     let enum_data = db.enum_data(e);
                     match enum_data.variant(&segment) {
                         Some(local_id) => {
@@ -385,10 +384,16 @@ impl DefMap {
                 }
             }
         };
-        let from_extern_prelude = self
-            .extern_prelude
-            .get(name)
-            .map_or(PerNs::none(), |&it| PerNs::types(it, Visibility::Public));
+        // Give precedence to names in outer `DefMap`s over the extern prelude; only check prelude
+        // from the crate DefMap.
+        let from_extern_prelude = match self.block {
+            Some(_) => PerNs::none(),
+            None => self
+                .extern_prelude
+                .get(name)
+                .map_or(PerNs::none(), |&it| PerNs::types(it, Visibility::Public)),
+        };
+
         let from_prelude = self.resolve_in_prelude(db, name);
 
         from_legacy_macro.or(from_scope_or_builtin).or(from_extern_prelude).or(from_prelude)
diff --git a/crates/hir_def/src/nameres/tests.rs b/crates/hir_def/src/nameres/tests.rs
index bd3e2701b..de3aa4f9a 100644
--- a/crates/hir_def/src/nameres/tests.rs
+++ b/crates/hir_def/src/nameres/tests.rs
@@ -9,7 +9,6 @@ use std::sync::Arc;
 
 use base_db::{fixture::WithFixture, SourceDatabase};
 use expect_test::{expect, Expect};
-use test_utils::mark;
 
 use crate::{db::DefDatabase, test_db::TestDB};
 
@@ -136,7 +135,7 @@ mod m {
 
 #[test]
 fn bogus_paths() {
-    mark::check!(bogus_paths);
+    cov_mark::check!(bogus_paths);
     check(
         r#"
 //- /lib.rs
@@ -243,7 +242,7 @@ pub struct Baz;
 
 #[test]
 fn std_prelude() {
-    mark::check!(std_prelude);
+    cov_mark::check!(std_prelude);
     check(
         r#"
 //- /main.rs crate:main deps:test_crate
@@ -267,7 +266,7 @@ pub enum Foo { Bar, Baz };
 
 #[test]
 fn can_import_enum_variant() {
-    mark::check!(can_import_enum_variant);
+    cov_mark::check!(can_import_enum_variant);
     check(
         r#"
 enum E { V }
@@ -628,7 +627,7 @@ use crate::reex::*;
 
 #[test]
 fn underscore_pub_crate_reexport() {
-    mark::check!(upgrade_underscore_visibility);
+    cov_mark::check!(upgrade_underscore_visibility);
     check(
         r#"
 //- /main.rs crate:main deps:lib
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
index e8e72e5ef..d5ef8ceb5 100644
--- a/crates/hir_def/src/nameres/tests/diagnostics.rs
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -1,5 +1,4 @@
 use base_db::fixture::WithFixture;
-use test_utils::mark;
 
 use crate::test_db::TestDB;
 
@@ -63,7 +62,7 @@ fn unresolved_extern_crate() {
 
 #[test]
 fn extern_crate_self_as() {
-    mark::check!(extern_crate_self_as);
+    cov_mark::check!(extern_crate_self_as);
     check_diagnostics(
         r"
         //- /lib.rs
@@ -140,7 +139,7 @@ fn inactive_item() {
 /// Tests that `cfg` attributes behind `cfg_attr` is handled properly.
 #[test]
 fn inactive_via_cfg_attr() {
-    mark::check!(cfg_attr_active);
+    cov_mark::check!(cfg_attr_active);
     check_diagnostics(
         r#"
         //- /lib.rs
diff --git a/crates/hir_def/src/nameres/tests/globs.rs b/crates/hir_def/src/nameres/tests/globs.rs
index 2ae836e3c..17426d54d 100644
--- a/crates/hir_def/src/nameres/tests/globs.rs
+++ b/crates/hir_def/src/nameres/tests/globs.rs
@@ -148,7 +148,7 @@ pub(crate) struct PubCrateStruct;
 
 #[test]
 fn glob_across_crates() {
-    mark::check!(glob_across_crates);
+    cov_mark::check!(glob_across_crates);
     check(
         r#"
 //- /main.rs crate:main deps:test_crate
@@ -184,7 +184,7 @@ struct Foo;
 
 #[test]
 fn glob_enum() {
-    mark::check!(glob_enum);
+    cov_mark::check!(glob_enum);
     check(
         r#"
 enum Foo { Bar, Baz }
@@ -201,7 +201,7 @@ use self::Foo::*;
 
 #[test]
 fn glob_enum_group() {
-    mark::check!(glob_enum_group);
+    cov_mark::check!(glob_enum_group);
     check(
         r#"
 enum Foo { Bar, Baz }
@@ -218,7 +218,7 @@ use self::Foo::{*};
 
 #[test]
 fn glob_shadowed_def() {
-    mark::check!(import_shadowed);
+    cov_mark::check!(import_shadowed);
     check(
         r#"
 //- /lib.rs
diff --git a/crates/hir_def/src/nameres/tests/macros.rs b/crates/hir_def/src/nameres/tests/macros.rs
index 36ed5e8ce..f65a655bf 100644
--- a/crates/hir_def/src/nameres/tests/macros.rs
+++ b/crates/hir_def/src/nameres/tests/macros.rs
@@ -210,7 +210,7 @@ macro_rules! bar {
 
 #[test]
 fn macro_rules_from_other_crates_are_visible_with_macro_use() {
-    mark::check!(macro_rules_from_other_crates_are_visible_with_macro_use);
+    cov_mark::check!(macro_rules_from_other_crates_are_visible_with_macro_use);
     check(
         r#"
 //- /main.rs crate:main deps:foo
@@ -260,7 +260,7 @@ mod priv_mod {
 
 #[test]
 fn prelude_is_macro_use() {
-    mark::check!(prelude_is_macro_use);
+    cov_mark::check!(prelude_is_macro_use);
     check(
         r#"
 //- /main.rs crate:main deps:foo
@@ -550,7 +550,7 @@ mod m {
 
 #[test]
 fn macro_dollar_crate_is_correct_in_item() {
-    mark::check!(macro_dollar_crate_self);
+    cov_mark::check!(macro_dollar_crate_self);
     check(
         r#"
 //- /main.rs crate:main deps:foo
@@ -608,7 +608,7 @@ struct Baz;
 
 #[test]
 fn macro_dollar_crate_is_correct_in_indirect_deps() {
-    mark::check!(macro_dollar_crate_other);
+    cov_mark::check!(macro_dollar_crate_other);
     // From std
     check(
         r#"
@@ -686,7 +686,7 @@ pub trait Clone {}
 
 #[test]
 fn macro_expansion_overflow() {
-    mark::check!(macro_expansion_overflow);
+    cov_mark::check!(macro_expansion_overflow);
     check(
         r#"
 macro_rules! a {
diff --git a/crates/hir_def/src/nameres/tests/mod_resolution.rs b/crates/hir_def/src/nameres/tests/mod_resolution.rs
index e80b593aa..dfbbad1f9 100644
--- a/crates/hir_def/src/nameres/tests/mod_resolution.rs
+++ b/crates/hir_def/src/nameres/tests/mod_resolution.rs
@@ -2,7 +2,7 @@ use super::*;
 
 #[test]
 fn name_res_works_for_broken_modules() {
-    mark::check!(name_res_works_for_broken_modules);
+    cov_mark::check!(name_res_works_for_broken_modules);
     check(
         r"
 //- /lib.rs
@@ -774,7 +774,7 @@ struct X;
 
 #[test]
 fn circular_mods() {
-    mark::check!(circular_mods);
+    cov_mark::check!(circular_mods);
     compute_crate_def_map(
         r#"
 //- /lib.rs
diff --git a/crates/hir_def/src/path/lower/lower_use.rs b/crates/hir_def/src/path/lower/lower_use.rs
index d584b0b70..e2965b033 100644
--- a/crates/hir_def/src/path/lower/lower_use.rs
+++ b/crates/hir_def/src/path/lower/lower_use.rs
@@ -6,7 +6,6 @@ use std::iter;
 use either::Either;
 use hir_expand::{hygiene::Hygiene, name::AsName};
 use syntax::ast::{self, NameOwner};
-use test_utils::mark;
 
 use crate::path::{ImportAlias, ModPath, PathKind};
 
@@ -54,7 +53,7 @@ pub(crate) fn lower_use_tree(
         // FIXME: report errors somewhere
         // We get here if we do
         } else if is_glob {
-            mark::hit!(glob_enum_group);
+            cov_mark::hit!(glob_enum_group);
             if let Some(prefix) = prefix {
                 cb(prefix, &tree, is_glob, None)
             }
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 77ff21739..42736171e 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -19,10 +19,10 @@ use crate::{
     path::{ModPath, PathKind},
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
-    AdtId, AssocContainerId, ConstId, ConstParamId, ContainerId, DefWithBodyId, EnumId,
-    EnumVariantId, FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId,
-    LocalModuleId, Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
-    TypeParamId, VariantId,
+    AdtId, AssocContainerId, ConstId, ConstParamId, DefWithBodyId, EnumId, EnumVariantId,
+    FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId, LocalModuleId,
+    Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
+    VariantId,
 };
 
 #[derive(Debug, Clone, Default)]
@@ -342,6 +342,16 @@ impl Resolver {
                     traits.extend(prelude_def_map[prelude.local_id].scope.traits());
                 }
                 traits.extend(m.def_map[m.module_id].scope.traits());
+
+                // Add all traits that are in scope because of the containing DefMaps
+                m.def_map.with_ancestor_maps(db, m.module_id, &mut |def_map, module| {
+                    if let Some(prelude) = def_map.prelude() {
+                        let prelude_def_map = prelude.def_map(db);
+                        traits.extend(prelude_def_map[prelude.local_id].scope.traits());
+                    }
+                    traits.extend(def_map[module].scope.traits());
+                    None::<()>
+                });
             }
         }
         traits
@@ -678,19 +688,10 @@ impl HasResolver for DefWithBodyId {
     }
 }
 
-impl HasResolver for ContainerId {
-    fn resolver(self, db: &dyn DefDatabase) -> Resolver {
-        match self {
-            ContainerId::ModuleId(it) => it.resolver(db),
-            ContainerId::DefWithBodyId(it) => it.module(db).resolver(db),
-        }
-    }
-}
-
 impl HasResolver for AssocContainerId {
     fn resolver(self, db: &dyn DefDatabase) -> Resolver {
         match self {
-            AssocContainerId::ContainerId(it) => it.resolver(db),
+            AssocContainerId::ModuleId(it) => it.resolver(db),
             AssocContainerId::TraitId(it) => it.resolver(db),
             AssocContainerId::ImplId(it) => it.resolver(db),
         }
diff --git a/crates/hir_def/src/test_db.rs b/crates/hir_def/src/test_db.rs
index eda982c85..10977761c 100644
--- a/crates/hir_def/src/test_db.rs
+++ b/crates/hir_def/src/test_db.rs
@@ -15,7 +15,7 @@ use rustc_hash::FxHashSet;
 use syntax::{algo, ast, AstNode, TextRange, TextSize};
 use test_utils::extract_annotations;
 
-use crate::{db::DefDatabase, nameres::DefMap, Lookup, ModuleDefId, ModuleId};
+use crate::{db::DefDatabase, nameres::DefMap, src::HasSource, Lookup, ModuleDefId, ModuleId};
 
 #[salsa::database(
     base_db::SourceDatabaseExtStorage,
@@ -115,14 +115,9 @@ impl TestDB {
             if file_id != position.file_id.into() {
                 continue;
             }
-            let root = self.parse_or_expand(file_id).unwrap();
-            let ast_map = self.ast_id_map(file_id);
-            let item_tree = self.item_tree(file_id);
             for decl in module.scope.declarations() {
                 if let ModuleDefId::FunctionId(it) = decl {
-                    let ast =
-                        ast_map.get(item_tree[it.lookup(self).id.value].ast_id).to_node(&root);
-                    let range = ast.syntax().text_range();
+                    let range = it.lookup(self).source(self).value.syntax().text_range();
 
                     if !range.contains(position.offset) {
                         continue;
diff --git a/crates/hir_expand/Cargo.toml b/crates/hir_expand/Cargo.toml
index 5271110d2..f649ab925 100644
--- a/crates/hir_expand/Cargo.toml
+++ b/crates/hir_expand/Cargo.toml
@@ -16,9 +16,13 @@ rustc-hash = "1.0.0"
 la-arena = { version = "0.2.0", path = "../../lib/arena" }
 
 base_db = { path = "../base_db", version = "0.0.0" }
+cfg = { path = "../cfg", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 parser = { path = "../parser", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
 mbe = { path = "../mbe", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
+
+[dev-dependencies]
+test_utils = { path = "../test_utils" }
+expect-test = "1.1"
diff --git a/crates/hir_expand/src/builtin_derive.rs b/crates/hir_expand/src/builtin_derive.rs
index b7f1aae8f..dfdb9cf59 100644
--- a/crates/hir_expand/src/builtin_derive.rs
+++ b/crates/hir_expand/src/builtin_derive.rs
@@ -267,13 +267,14 @@ fn partial_ord_expand(
 #[cfg(test)]
 mod tests {
     use base_db::{fixture::WithFixture, CrateId, SourceDatabase};
+    use expect_test::{expect, Expect};
     use name::{known, Name};
 
     use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
 
     use super::*;
 
-    fn expand_builtin_derive(s: &str, name: Name) -> String {
+    fn expand_builtin_derive(ra_fixture: &str, name: Name) -> String {
         let expander = BuiltinDeriveExpander::find_by_name(&name).unwrap();
         let fixture = format!(
             r#"//- /main.rs crate:main deps:core
@@ -282,7 +283,7 @@ $0
 //- /lib.rs crate:core
 // empty
 "#,
-            s
+            ra_fixture
         );
 
         let (db, file_pos) = TestDB::with_position(&fixture);
@@ -314,66 +315,57 @@ $0
         parsed.text().to_string()
     }
 
+    fn check_derive(ra_fixture: &str, name: Name, expected: Expect) {
+        let expanded = expand_builtin_derive(ra_fixture, name);
+        expected.assert_eq(&expanded);
+    }
+
     #[test]
     fn test_copy_expand_simple() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo;
-"#,
+            #[derive(Copy)]
+            struct Foo;
+            "#,
             known::Copy,
+            expect![["impl< >core::marker::CopyforFoo< >{}"]],
         );
-
-        assert_eq!(expanded, "impl< >core::marker::CopyforFoo< >{}");
     }
 
     #[test]
     fn test_copy_expand_with_type_params() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo<A, B>;
-"#,
+            #[derive(Copy)]
+            struct Foo<A, B>;
+            "#,
             known::Copy,
-        );
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
+            expect![["impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"]],
         );
     }
 
     #[test]
     fn test_copy_expand_with_lifetimes() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Copy)]
-        struct Foo<A, B, 'a, 'b>;
-"#,
+            #[derive(Copy)]
+            struct Foo<A, B, 'a, 'b>;
+            "#,
             known::Copy,
-        );
-
-        // We currently just ignore lifetimes
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
+            // We currently just ignore lifetimes
+            expect![["impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"]],
         );
     }
 
     #[test]
     fn test_clone_expand() {
-        let expanded = expand_builtin_derive(
+        check_derive(
             r#"
-        #[derive(Clone)]
-        struct Foo<A, B>;
-"#,
+            #[derive(Clone)]
+            struct Foo<A, B>;
+            "#,
             known::Clone,
-        );
-
-        assert_eq!(
-            expanded,
-            "impl<T0:core::clone::Clone,T1:core::clone::Clone>core::clone::CloneforFoo<T0,T1>{}"
+            expect![["impl<T0:core::clone::Clone,T1:core::clone::Clone>core::clone::CloneforFoo<T0,T1>{}"]],
         );
     }
 }
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index eb57ea7d6..2a79c892b 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -5,6 +5,7 @@ use crate::{
 };
 
 use base_db::{AnchoredPath, FileId};
+use cfg::CfgExpr;
 use either::Either;
 use mbe::{parse_exprs_with_sep, parse_to_token_tree, ExpandResult};
 use parser::FragmentKind;
@@ -97,6 +98,7 @@ register_builtin! {
     (format_args_nl, FormatArgsNl) => format_args_expand,
     (llvm_asm, LlvmAsm) => asm_expand,
     (asm, Asm) => asm_expand,
+    (cfg, Cfg) => cfg_expand,
 
     EAGER:
     (compile_error, CompileError) => compile_error_expand,
@@ -258,6 +260,18 @@ fn asm_expand(
     ExpandResult::ok(expanded)
 }
 
+fn cfg_expand(
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
+    tt: &tt::Subtree,
+) -> ExpandResult<tt::Subtree> {
+    let loc = db.lookup_intern_macro(id);
+    let expr = CfgExpr::parse(tt);
+    let enabled = db.crate_graph()[loc.krate].cfg_options.check(&expr) != Some(false);
+    let expanded = if enabled { quote!(true) } else { quote!(false) };
+    ExpandResult::ok(expanded)
+}
+
 fn unquote_str(lit: &tt::Literal) -> Option<String> {
     let lit = ast::make::tokens::literal(&lit.to_string());
     let token = ast::String::cast(lit)?;
@@ -477,6 +491,7 @@ mod tests {
         MacroCallLoc,
     };
     use base_db::{fixture::WithFixture, SourceDatabase};
+    use expect_test::{expect, Expect};
     use std::sync::Arc;
     use syntax::ast::NameOwner;
 
@@ -560,87 +575,86 @@ mod tests {
         db.parse_or_expand(file_id).unwrap().to_string()
     }
 
+    fn check_expansion(ra_fixture: &str, expect: Expect) {
+        let expansion = expand_builtin_macro(ra_fixture);
+        expect.assert_eq(&expansion);
+    }
+
     #[test]
     fn test_column_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! column {() => {}}
             column!()
             "#,
+            expect![["0"]],
         );
-
-        assert_eq!(expanded, "0");
     }
 
     #[test]
     fn test_line_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! line {() => {}}
             line!()
             "#,
+            expect![["0"]],
         );
-
-        assert_eq!(expanded, "0");
     }
 
     #[test]
     fn test_stringify_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! stringify {() => {}}
             stringify!(a b c)
             "#,
+            expect![["\"a b c\""]],
         );
-
-        assert_eq!(expanded, "\"a b c\"");
     }
 
     #[test]
     fn test_env_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! env {() => {}}
             env!("TEST_ENV_VAR")
             "#,
+            expect![["\"__RA_UNIMPLEMENTED__\""]],
         );
-
-        assert_eq!(expanded, "\"__RA_UNIMPLEMENTED__\"");
     }
 
     #[test]
     fn test_option_env_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! option_env {() => {}}
             option_env!("TEST_ENV_VAR")
             "#,
+            expect![["std::option::Option::None:: < &str>"]],
         );
-
-        assert_eq!(expanded, "std::option::Option::None:: < &str>");
     }
 
     #[test]
     fn test_file_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! file {() => {}}
             file!()
             "#,
+            expect![[r#""""#]],
         );
-
-        assert_eq!(expanded, "\"\"");
     }
 
     #[test]
     fn test_assert_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! assert {
@@ -649,14 +663,13 @@ mod tests {
             }
             assert!(true, "{} {:?}", arg1(a, b, c), arg2);
             "#,
+            expect![["{{(&(true), &(\"{} {:?}\"), &(arg1(a,b,c)), &(arg2),);}}"]],
         );
-
-        assert_eq!(expanded, "{{(&(true), &(\"{} {:?}\"), &(arg1(a,b,c)), &(arg2),);}}");
     }
 
     #[test]
     fn test_compile_error_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! compile_error {
@@ -665,15 +678,14 @@ mod tests {
             }
             compile_error!("error!");
             "#,
+            // This expands to nothing (since it's in item position), but emits an error.
+            expect![[""]],
         );
-
-        // This expands to nothing (since it's in item position), but emits an error.
-        assert_eq!(expanded, "");
     }
 
     #[test]
     fn test_format_args_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! format_args {
@@ -682,17 +694,15 @@ mod tests {
             }
             format_args!("{} {:?}", arg1(a, b, c), arg2);
             "#,
-        );
-
-        assert_eq!(
-            expanded,
-            r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+            expect![[
+                r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+            ]],
         );
     }
 
     #[test]
     fn test_format_args_expand_with_comma_exprs() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! format_args {
@@ -701,17 +711,15 @@ mod tests {
             }
             format_args!("{} {:?}", a::<A,B>(), b);
             "#,
-        );
-
-        assert_eq!(
-            expanded,
-            r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(a::<A,B>()),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(b),std::fmt::Display::fmt),])"#
+            expect![[
+                r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(a::<A,B>()),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(b),std::fmt::Display::fmt),])"#
+            ]],
         );
     }
 
     #[test]
     fn test_include_bytes_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r#"
             #[rustc_builtin_macro]
             macro_rules! include_bytes {
@@ -720,21 +728,19 @@ mod tests {
             }
             include_bytes("foo");
             "#,
+            expect![[r#"b"""#]],
         );
-
-        assert_eq!(expanded, r#"b"""#);
     }
 
     #[test]
     fn test_concat_expand() {
-        let expanded = expand_builtin_macro(
+        check_expansion(
             r##"
             #[rustc_builtin_macro]
             macro_rules! concat {}
             concat!("foo", "r", 0, r#"bar"#, false);
             "##,
+            expect![[r#""foor0barfalse""#]],
         );
-
-        assert_eq!(expanded, r#""foor0barfalse""#);
     }
 }
diff --git a/crates/hir_expand/src/name.rs b/crates/hir_expand/src/name.rs
index c94fb580a..e833e032c 100644
--- a/crates/hir_expand/src/name.rs
+++ b/crates/hir_expand/src/name.rs
@@ -154,6 +154,7 @@ pub mod known {
         macro_rules,
         derive,
         doc,
+        cfg,
         cfg_attr,
         // Components of known path (value or mod name)
         std,
diff --git a/crates/hir_expand/src/quote.rs b/crates/hir_expand/src/quote.rs
index 219bc2097..08bc5aa49 100644
--- a/crates/hir_expand/src/quote.rs
+++ b/crates/hir_expand/src/quote.rs
@@ -188,8 +188,9 @@ macro_rules! impl_to_to_tokentrees {
 
 impl_to_to_tokentrees! {
     u32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
-    usize => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
-    i32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
+    usize => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
+    i32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
+    bool => self { tt::Ident{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
     tt::Leaf => self { self };
     tt::Literal => self { self };
     tt::Ident => self { self };
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index d1302d749..b9c93f56f 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 itertools = "0.10.0"
 arrayvec = "0.5.1"
 smallvec = "1.2.0"
@@ -17,9 +18,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.59", default-features = false }
-chalk-ir = "0.59"
-chalk-recursive = "0.59"
+chalk-solve = { version = "0.60", default-features = false }
+chalk-ir = "0.60"
+chalk-recursive = "0.60"
 la-arena = { version = "0.2.0", path = "../../lib/arena" }
 
 stdx = { path = "../stdx", version = "0.0.0" }
@@ -28,9 +29,9 @@ hir_expand = { path = "../hir_expand", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils"  }
 expect-test = "1.1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.2", default-features = false, features = ["env-filter", "registry"] }
diff --git a/crates/hir_ty/src/diagnostics.rs b/crates/hir_ty/src/diagnostics.rs
index 6bca7aa0d..86f937e1d 100644
--- a/crates/hir_ty/src/diagnostics.rs
+++ b/crates/hir_ty/src/diagnostics.rs
@@ -706,6 +706,35 @@ fn x(a: S) {
     }
 
     #[test]
+    fn import_extern_crate_clash_with_inner_item() {
+        // This is more of a resolver test, but doesn't really work with the hir_def testsuite.
+
+        check_diagnostics(
+            r#"
+//- /lib.rs crate:lib deps:jwt
+mod permissions;
+
+use permissions::jwt;
+
+fn f() {
+    fn inner() {}
+    jwt::Claims {}; // should resolve to the local one with 0 fields, and not get a diagnostic
+}
+
+//- /permissions.rs
+pub mod jwt  {
+    pub struct Claims {}
+}
+
+//- /jwt/lib.rs crate:jwt
+pub struct Claims {
+    field: u8,
+}
+        "#,
+        );
+    }
+
+    #[test]
     fn break_outside_of_loop() {
         check_diagnostics(
             r#"
diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 6773ddea3..3605ca581 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -28,7 +28,6 @@ use syntax::{
     ast::{self, NameOwner},
     AstNode, AstPtr,
 };
-use test_utils::mark;
 
 use crate::{
     db::HirDatabase,
@@ -93,16 +92,21 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_func(&mut self, func: FunctionId) {
         let data = self.db.function_data(func);
         if data.is_extern {
-            mark::hit!(extern_func_incorrect_case_ignored);
+            cov_mark::hit!(extern_func_incorrect_case_ignored);
             return;
         }
 
         let body = self.db.body(func.into());
 
         // Recursively validate inner scope items, such as static variables and constants.
-        for (item_id, _) in body.item_scope.values() {
-            let mut validator = DeclValidator::new(self.db, self.krate, self.sink);
-            validator.validate_item(item_id);
+        let db = self.db;
+        for block_def_map in body.block_scopes.iter().filter_map(|block| db.block_def_map(*block)) {
+            for (_, module) in block_def_map.modules() {
+                for (def_id, _) in module.scope.values() {
+                    let mut validator = DeclValidator::new(self.db, self.krate, self.sink);
+                    validator.validate_item(def_id);
+                }
+            }
         }
 
         // Check whether non-snake case identifiers are allowed for this function.
@@ -625,7 +629,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_static(&mut self, static_id: StaticId) {
         let data = self.db.static_data(static_id);
         if data.is_extern {
-            mark::hit!(extern_static_incorrect_case_ignored);
+            cov_mark::hit!(extern_static_incorrect_case_ignored);
             return;
         }
 
@@ -673,8 +677,6 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::diagnostics::tests::check_diagnostics;
 
     #[test]
@@ -889,8 +891,8 @@ fn main() {
 
     #[test]
     fn ignores_extern_items() {
-        mark::check!(extern_func_incorrect_case_ignored);
-        mark::check!(extern_static_incorrect_case_ignored);
+        cov_mark::check!(extern_func_incorrect_case_ignored);
+        cov_mark::check!(extern_static_incorrect_case_ignored);
         check_diagnostics(
             r#"
 extern {
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index a0882a2a1..ab51cb0a6 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -6,7 +6,7 @@ use arrayvec::ArrayVec;
 use chalk_ir::Mutability;
 use hir_def::{
     db::DefDatabase, find_path, generics::TypeParamProvenance, item_scope::ItemInNs,
-    AssocContainerId, HasModule, Lookup, ModuleId, TraitId,
+    AssocContainerId, Lookup, ModuleId, TraitId,
 };
 use hir_expand::name::Name;
 
@@ -611,7 +611,7 @@ impl HirDisplay for CallableSig {
 }
 
 fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator<Item = TraitId> {
-    let krate = trait_.lookup(db).container.module(db).krate();
+    let krate = trait_.lookup(db).container.krate();
     let fn_traits = [
         db.lang_item(krate, "fn".into()),
         db.lang_item(krate, "fn_mut".into()),
diff --git a/crates/hir_ty/src/infer/coerce.rs b/crates/hir_ty/src/infer/coerce.rs
index cf0a3add4..7e8846f27 100644
--- a/crates/hir_ty/src/infer/coerce.rs
+++ b/crates/hir_ty/src/infer/coerce.rs
@@ -6,7 +6,6 @@
 
 use chalk_ir::{Mutability, TyVariableKind};
 use hir_def::lang_item::LangItemTarget;
-use test_utils::mark;
 
 use crate::{autoderef, traits::Solution, Obligation, Substs, TraitRef, Ty};
 
@@ -35,7 +34,7 @@ impl<'a> InferenceContext<'a> {
             ty1.clone()
         } else {
             if let (Ty::FnDef(..), Ty::FnDef(..)) = (ty1, ty2) {
-                mark::hit!(coerce_fn_reification);
+                cov_mark::hit!(coerce_fn_reification);
                 // Special case: two function types. Try to coerce both to
                 // pointers to have a chance at getting a match. See
                 // https://github.com/rust-lang/rust/blob/7b805396bf46dce972692a6846ce2ad8481c5f85/src/librustc_typeck/check/coercion.rs#L877-L916
@@ -45,7 +44,7 @@ impl<'a> InferenceContext<'a> {
                 let ptr_ty2 = Ty::fn_ptr(sig2);
                 self.coerce_merge_branch(&ptr_ty1, &ptr_ty2)
             } else {
-                mark::hit!(coerce_merge_fail_fallback);
+                cov_mark::hit!(coerce_merge_fail_fallback);
                 ty1.clone()
             }
         }
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index ec2c13154..262177ffb 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -12,7 +12,6 @@ use hir_def::{
 };
 use hir_expand::name::{name, Name};
 use syntax::ast::RangeOp;
-use test_utils::mark;
 
 use crate::{
     autoderef,
@@ -565,7 +564,7 @@ impl<'a> InferenceContext<'a> {
                     let ret = op::binary_op_return_ty(*op, lhs_ty.clone(), rhs_ty.clone());
 
                     if ret == Ty::Unknown {
-                        mark::hit!(infer_expr_inner_binary_operator_overload);
+                        cov_mark::hit!(infer_expr_inner_binary_operator_overload);
 
                         self.resolve_associated_type_with_params(
                             lhs_ty,
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
index 987793e2e..a0ac8d80f 100644
--- a/crates/hir_ty/src/infer/pat.rs
+++ b/crates/hir_ty/src/infer/pat.rs
@@ -10,7 +10,6 @@ use hir_def::{
     FieldId,
 };
 use hir_expand::name::Name;
-use test_utils::mark;
 
 use super::{BindingMode, Expectation, InferenceContext};
 use crate::{lower::lower_to_chalk_mutability, utils::variant_data, Substs, Ty};
@@ -108,7 +107,7 @@ impl<'a> InferenceContext<'a> {
                 }
             }
         } else if let Pat::Ref { .. } = &body[pat] {
-            mark::hit!(match_ergonomics_ref);
+            cov_mark::hit!(match_ergonomics_ref);
             // When you encounter a `&pat` pattern, reset to Move.
             // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
             default_bm = BindingMode::Move;
diff --git a/crates/hir_ty/src/infer/path.rs b/crates/hir_ty/src/infer/path.rs
index 5d541104e..ae3554bac 100644
--- a/crates/hir_ty/src/infer/path.rs
+++ b/crates/hir_ty/src/infer/path.rs
@@ -260,7 +260,7 @@ impl<'a> InferenceContext<'a> {
                         }));
                         Some(trait_substs)
                     }
-                    AssocContainerId::ContainerId(_) => None,
+                    AssocContainerId::ModuleId(_) => None,
                 };
 
                 self.write_assoc_resolution(id, item);
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 99a89a7f3..54fcfed10 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -5,8 +5,6 @@ use std::borrow::Cow;
 use chalk_ir::{FloatTy, IntTy, TyVariableKind};
 use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
 
-use test_utils::mark;
-
 use super::{InferenceContext, Obligation};
 use crate::{
     BoundVar, Canonical, DebruijnIndex, GenericPredicate, InEnvironment, InferenceVar, Scalar,
@@ -387,7 +385,7 @@ impl InferenceTable {
         // more than once
         for i in 0..3 {
             if i > 0 {
-                mark::hit!(type_var_resolves_to_int_var);
+                cov_mark::hit!(type_var_resolves_to_int_var);
             }
             match &*ty {
                 Ty::InferenceVar(tv, _) => {
@@ -416,7 +414,7 @@ impl InferenceTable {
             Ty::InferenceVar(tv, kind) => {
                 let inner = tv.to_inner();
                 if tv_stack.contains(&inner) {
-                    mark::hit!(type_var_cycles_resolve_as_possible);
+                    cov_mark::hit!(type_var_cycles_resolve_as_possible);
                     // recursive type
                     return self.type_variable_table.fallback_value(tv, kind);
                 }
@@ -443,7 +441,7 @@ impl InferenceTable {
             Ty::InferenceVar(tv, kind) => {
                 let inner = tv.to_inner();
                 if tv_stack.contains(&inner) {
-                    mark::hit!(type_var_cycles_resolve_completely);
+                    cov_mark::hit!(type_var_cycles_resolve_completely);
                     // recursive type
                     return self.type_variable_table.fallback_value(tv, kind);
                 }
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 5fe5b8ad1..d84ec9b7a 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -8,7 +8,7 @@
 use std::{iter, sync::Arc};
 
 use base_db::CrateId;
-use chalk_ir::Mutability;
+use chalk_ir::{cast::Cast, Mutability};
 use hir_def::{
     adt::StructKind,
     builtin_type::BuiltinType,
@@ -24,10 +24,10 @@ use hir_expand::name::Name;
 use la_arena::ArenaMap;
 use smallvec::SmallVec;
 use stdx::impl_from;
-use test_utils::mark;
 
 use crate::{
     db::HirDatabase,
+    traits::chalk::{Interner, ToChalk},
     utils::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
         make_mut_slice, variant_data,
@@ -760,7 +760,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
 
 impl ReturnTypeImplTrait {
     fn from_hir(ctx: &TyLoweringContext, bounds: &[TypeBound]) -> Self {
-        mark::hit!(lower_rpit);
+        cov_mark::hit!(lower_rpit);
         let self_ty = Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0));
         let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
             bounds
@@ -915,10 +915,21 @@ impl TraitEnvironment {
     pub fn lower(db: &dyn HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
         let ctx = TyLoweringContext::new(db, &resolver)
             .with_type_param_mode(TypeParamLoweringMode::Placeholder);
-        let mut predicates = resolver
-            .where_predicates_in_scope()
-            .flat_map(|pred| GenericPredicate::from_where_predicate(&ctx, pred))
-            .collect::<Vec<_>>();
+        let mut traits_in_scope = Vec::new();
+        let mut clauses = Vec::new();
+        for pred in resolver.where_predicates_in_scope() {
+            for pred in GenericPredicate::from_where_predicate(&ctx, pred) {
+                if pred.is_error() {
+                    continue;
+                }
+                if let GenericPredicate::Implemented(tr) = &pred {
+                    traits_in_scope.push((tr.self_ty().clone(), tr.trait_));
+                }
+                let program_clause: chalk_ir::ProgramClause<Interner> =
+                    pred.clone().to_chalk(db).cast(&Interner);
+                clauses.push(program_clause.into_from_env_clause(&Interner));
+            }
+        }
 
         if let Some(def) = resolver.generic_def() {
             let container: Option<AssocContainerId> = match def {
@@ -935,16 +946,19 @@ impl TraitEnvironment {
                 // add `Self: Trait<T1, T2, ...>` to the environment in trait
                 // function default implementations (and hypothetical code
                 // inside consts or type aliases)
-                test_utils::mark::hit!(trait_self_implements_self);
+                cov_mark::hit!(trait_self_implements_self);
                 let substs = Substs::type_params(db, trait_id);
                 let trait_ref = TraitRef { trait_: trait_id, substs };
                 let pred = GenericPredicate::Implemented(trait_ref);
-
-                predicates.push(pred);
+                let program_clause: chalk_ir::ProgramClause<Interner> =
+                    pred.clone().to_chalk(db).cast(&Interner);
+                clauses.push(program_clause.into_from_env_clause(&Interner));
             }
         }
 
-        Arc::new(TraitEnvironment { predicates })
+        let env = chalk_ir::Environment::new(&Interner).add_clauses(&Interner, clauses);
+
+        Arc::new(TraitEnvironment { traits_from_clauses: traits_in_scope, env })
     }
 }
 
@@ -1131,8 +1145,8 @@ impl CallableDefId {
         let db = db.upcast();
         match self {
             CallableDefId::FunctionId(f) => f.lookup(db).module(db),
-            CallableDefId::StructId(s) => s.lookup(db).container.module(db),
-            CallableDefId::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
+            CallableDefId::StructId(s) => s.lookup(db).container,
+            CallableDefId::EnumVariantId(e) => e.parent.lookup(db).container,
         }
         .krate()
     }
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index dfcf346fb..d57c6de70 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -267,7 +267,7 @@ impl Ty {
                 LangItemTarget::ImplDefId(it) => Some(it),
                 _ => None,
             })
-            .map(|it| it.lookup(db.upcast()).container.module(db.upcast()).krate())
+            .map(|it| it.lookup(db.upcast()).container.krate())
             .collect();
         Some(res)
     }
@@ -528,8 +528,7 @@ fn iterate_trait_method_candidates(
         self_ty.value.dyn_trait().into_iter().flat_map(|t| all_super_traits(db.upcast(), t));
     let env_traits = if let Ty::Placeholder(_) = self_ty.value {
         // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
-        env.trait_predicates_for_self_ty(&self_ty.value)
-            .map(|tr| tr.trait_)
+        env.traits_in_scope_from_clauses(&self_ty.value)
             .flat_map(|t| all_super_traits(db.upcast(), t))
             .collect()
     } else {
@@ -588,7 +587,7 @@ fn iterate_inherent_methods(
                 // already happens in `is_valid_candidate` above; if not, we
                 // check it here
                 if receiver_ty.is_none() && inherent_impl_substs(db, impl_def, self_ty).is_none() {
-                    test_utils::mark::hit!(impl_self_type_match_without_receiver);
+                    cov_mark::hit!(impl_self_type_match_without_receiver);
                     continue;
                 }
                 if callback(&self_ty.value, item) {
@@ -715,7 +714,7 @@ fn transform_receiver_ty(
                 .fill_with_unknown()
                 .build()
         }
-        AssocContainerId::ContainerId(_) => unreachable!(),
+        AssocContainerId::ModuleId(_) => unreachable!(),
     };
     let sig = db.callable_item_signature(function_id.into());
     Some(sig.value.params()[0].clone().subst_bound_vars(&substs))
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index 7386a4e7b..0a4141e69 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -13,12 +13,13 @@ use std::{env, sync::Arc};
 use base_db::{fixture::WithFixture, FileRange, SourceDatabase, SourceDatabaseExt};
 use expect_test::Expect;
 use hir_def::{
-    body::{BodySourceMap, SyntheticSyntax},
+    body::{Body, BodySourceMap, SyntheticSyntax},
     child_by_source::ChildBySource,
     db::DefDatabase,
     item_scope::ItemScope,
     keys,
     nameres::DefMap,
+    src::HasSource,
     AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
 use hir_expand::{db::AstDatabase, InFile};
@@ -195,18 +196,15 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
     defs.sort_by_key(|def| match def {
         DefWithBodyId::FunctionId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
         DefWithBodyId::ConstId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
         DefWithBodyId::StaticId(it) => {
             let loc = it.lookup(&db);
-            let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id).syntax().text_range().start()
+            loc.source(&db).value.syntax().text_range().start()
         }
     });
     for def in defs {
@@ -234,13 +232,13 @@ fn visit_module(
                     let def = it.into();
                     cb(def);
                     let body = db.body(def);
-                    visit_scope(db, crate_def_map, &body.item_scope, cb);
+                    visit_body(db, &body, cb);
                 }
                 AssocItemId::ConstId(it) => {
                     let def = it.into();
                     cb(def);
                     let body = db.body(def);
-                    visit_scope(db, crate_def_map, &body.item_scope, cb);
+                    visit_body(db, &body, cb);
                 }
                 AssocItemId::TypeAliasId(_) => (),
             }
@@ -259,19 +257,19 @@ fn visit_module(
                     let def = it.into();
                     cb(def);
                     let body = db.body(def);
-                    visit_scope(db, crate_def_map, &body.item_scope, cb);
+                    visit_body(db, &body, cb);
                 }
                 ModuleDefId::ConstId(it) => {
                     let def = it.into();
                     cb(def);
                     let body = db.body(def);
-                    visit_scope(db, crate_def_map, &body.item_scope, cb);
+                    visit_body(db, &body, cb);
                 }
                 ModuleDefId::StaticId(it) => {
                     let def = it.into();
                     cb(def);
                     let body = db.body(def);
-                    visit_scope(db, crate_def_map, &body.item_scope, cb);
+                    visit_body(db, &body, cb);
                 }
                 ModuleDefId::TraitId(it) => {
                     let trait_data = db.trait_data(it);
@@ -288,6 +286,14 @@ fn visit_module(
             }
         }
     }
+
+    fn visit_body(db: &TestDB, body: &Body, cb: &mut dyn FnMut(DefWithBodyId)) {
+        for def_map in body.block_scopes.iter().filter_map(|block| db.block_def_map(*block)) {
+            for (mod_id, _) in def_map.modules() {
+                visit_module(db, &def_map, mod_id, cb);
+            }
+        }
+    }
 }
 
 fn ellipsize(mut text: String, max_len: usize) -> String {
diff --git a/crates/hir_ty/src/tests/coercion.rs b/crates/hir_ty/src/tests/coercion.rs
index 7bc6c79f3..63d9d4e0b 100644
--- a/crates/hir_ty/src/tests/coercion.rs
+++ b/crates/hir_ty/src/tests/coercion.rs
@@ -1,5 +1,4 @@
 use expect_test::expect;
-use test_utils::mark;
 
 use super::{check_infer, check_infer_with_mismatches};
 
@@ -381,7 +380,7 @@ fn infer_match_second_coerce() {
 
 #[test]
 fn coerce_merge_one_by_one1() {
-    mark::check!(coerce_merge_fail_fallback);
+    cov_mark::check!(coerce_merge_fail_fallback);
 
     check_infer(
         r"
@@ -589,7 +588,7 @@ fn coerce_fn_item_to_fn_ptr() {
 
 #[test]
 fn coerce_fn_items_in_match_arms() {
-    mark::check!(coerce_fn_reification);
+    cov_mark::check!(coerce_fn_reification);
 
     check_infer_with_mismatches(
         r"
diff --git a/crates/hir_ty/src/tests/method_resolution.rs b/crates/hir_ty/src/tests/method_resolution.rs
index a9901d7b8..4e3f9a9b6 100644
--- a/crates/hir_ty/src/tests/method_resolution.rs
+++ b/crates/hir_ty/src/tests/method_resolution.rs
@@ -913,7 +913,7 @@ fn test() { S2.into(); }
 
 #[test]
 fn method_resolution_overloaded_method() {
-    test_utils::mark::check!(impl_self_type_match_without_receiver);
+    cov_mark::check!(impl_self_type_match_without_receiver);
     check_types(
         r#"
 struct Wrapper<T>(T);
diff --git a/crates/hir_ty/src/tests/patterns.rs b/crates/hir_ty/src/tests/patterns.rs
index 2053d8f56..5da19ba5f 100644
--- a/crates/hir_ty/src/tests/patterns.rs
+++ b/crates/hir_ty/src/tests/patterns.rs
@@ -1,5 +1,4 @@
 use expect_test::expect;
-use test_utils::mark;
 
 use super::{check_infer, check_infer_with_mismatches};
 
@@ -197,7 +196,7 @@ fn infer_pattern_match_ergonomics() {
 
 #[test]
 fn infer_pattern_match_ergonomics_ref() {
-    mark::check!(match_ergonomics_ref);
+    cov_mark::check!(match_ergonomics_ref);
     check_infer(
         r#"
         fn test() {
diff --git a/crates/hir_ty/src/tests/regression.rs b/crates/hir_ty/src/tests/regression.rs
index cffe8630b..69314e245 100644
--- a/crates/hir_ty/src/tests/regression.rs
+++ b/crates/hir_ty/src/tests/regression.rs
@@ -1,5 +1,4 @@
 use expect_test::expect;
-use test_utils::mark;
 
 use super::{check_infer, check_types};
 
@@ -87,8 +86,8 @@ fn bug_651() {
 
 #[test]
 fn recursive_vars() {
-    mark::check!(type_var_cycles_resolve_completely);
-    mark::check!(type_var_cycles_resolve_as_possible);
+    cov_mark::check!(type_var_cycles_resolve_completely);
+    cov_mark::check!(type_var_cycles_resolve_as_possible);
     check_infer(
         r#"
         fn test() {
@@ -166,7 +165,7 @@ fn infer_std_crash_1() {
 
 #[test]
 fn infer_std_crash_2() {
-    mark::check!(type_var_resolves_to_int_var);
+    cov_mark::check!(type_var_resolves_to_int_var);
     // caused "equating two type variables, ...", taken from std
     check_infer(
         r#"
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 2947857a5..f5069eba5 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -1,5 +1,4 @@
 use expect_test::expect;
-use test_utils::mark;
 
 use super::{check_infer, check_types};
 
@@ -2314,7 +2313,7 @@ fn generic_default_depending_on_other_type_arg_forward() {
 
 #[test]
 fn infer_operator_overload() {
-    mark::check!(infer_expr_inner_binary_operator_overload);
+    cov_mark::check!(infer_expr_inner_binary_operator_overload);
 
     check_infer(
         r#"
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index 1298e5a88..e185b1c0a 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -1,5 +1,4 @@
 use expect_test::expect;
-use test_utils::mark;
 
 use super::{check_infer, check_infer_with_mismatches, check_types};
 
@@ -319,7 +318,7 @@ fn infer_from_bound_2() {
 
 #[test]
 fn trait_default_method_self_bound_implements_trait() {
-    mark::check!(trait_self_implements_self);
+    cov_mark::check!(trait_self_implements_self);
     check_infer(
         r#"
         trait Trait {
@@ -1189,7 +1188,7 @@ fn impl_trait() {
 
 #[test]
 fn simple_return_pos_impl_trait() {
-    mark::check!(lower_rpit);
+    cov_mark::check!(lower_rpit);
     check_infer(
         r#"
         trait Trait<T> {
@@ -3175,6 +3174,39 @@ fn f() {
 }
 
 #[test]
+fn trait_in_scope_with_inner_item() {
+    check_infer(
+        r#"
+mod m {
+    pub trait Tr {
+        fn method(&self) -> u8 { 0 }
+    }
+
+    impl Tr for () {}
+}
+
+use m::Tr;
+
+fn f() {
+    fn inner() {
+        ().method();
+      //^^^^^^^^^^^ u8
+    }
+}
+        "#,
+        expect![[r#"
+            46..50 'self': &Self
+            58..63 '{ 0 }': u8
+            60..61 '0': u8
+            115..185 '{     ...   } }': ()
+            132..183 '{     ...     }': ()
+            142..144 '()': ()
+            142..153 '().method()': u8
+        "#]],
+    );
+}
+
+#[test]
 fn inner_use_in_block() {
     check_types(
         r#"
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index e4cdb6d53..27f350f70 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -38,22 +38,25 @@ fn create_chalk_solver() -> chalk_recursive::RecursiveSolver<Interner> {
 /// fn foo<T: Default>(t: T) {}
 /// ```
 /// we assume that `T: Default`.
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct TraitEnvironment {
-    pub predicates: Vec<GenericPredicate>,
+    // When we're using Chalk's Ty we can make this a BTreeMap since it's Ord,
+    // but for now it's too annoying...
+    pub(crate) traits_from_clauses: Vec<(Ty, TraitId)>,
+    pub(crate) env: chalk_ir::Environment<Interner>,
 }
 
 impl TraitEnvironment {
-    /// Returns trait refs with the given self type which are supposed to hold
-    /// in this trait env. E.g. if we are in `foo<T: SomeTrait>()`, this will
-    /// find that `T: SomeTrait` if we call it for `T`.
-    pub(crate) fn trait_predicates_for_self_ty<'a>(
+    pub(crate) fn traits_in_scope_from_clauses<'a>(
         &'a self,
         ty: &'a Ty,
-    ) -> impl Iterator<Item = &'a TraitRef> + 'a {
-        self.predicates.iter().filter_map(move |pred| match pred {
-            GenericPredicate::Implemented(tr) if tr.self_ty() == ty => Some(tr),
-            _ => None,
+    ) -> impl Iterator<Item = TraitId> + 'a {
+        self.traits_from_clauses.iter().filter_map(move |(self_ty, trait_id)| {
+            if self_ty == ty {
+                Some(*trait_id)
+            } else {
+                None
+            }
         })
     }
 }
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index 4378a9723..1a2a3a8c7 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -33,13 +33,13 @@ pub(super) mod tls;
 mod interner;
 mod mapping;
 
-pub(super) trait ToChalk {
+pub(crate) trait ToChalk {
     type Chalk;
     fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk;
     fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self;
 }
 
-pub(super) fn from_chalk<T, ChalkT>(db: &dyn HirDatabase, chalk: ChalkT) -> T
+pub(crate) fn from_chalk<T, ChalkT>(db: &dyn HirDatabase, chalk: ChalkT) -> T
 where
     T: ToChalk<Chalk = ChalkT>,
 {
@@ -424,7 +424,7 @@ pub(crate) fn trait_datum_query(
     let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
     let flags = rust_ir::TraitFlags {
         auto: trait_data.auto,
-        upstream: trait_.lookup(db.upcast()).container.module(db.upcast()).krate() != krate,
+        upstream: trait_.lookup(db.upcast()).container.krate() != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
         // FIXME: set these flags correctly
@@ -487,19 +487,14 @@ pub(crate) fn struct_datum_query(
     struct_id: AdtId,
 ) -> Arc<StructDatum> {
     debug!("struct_datum {:?}", struct_id);
-    let type_ctor = Ty::Adt(struct_id, Substs::empty());
     let chalk_ir::AdtId(adt_id) = struct_id;
-    debug!("struct {:?} = {:?}", struct_id, type_ctor);
     let num_params = generics(db.upcast(), adt_id.into()).len();
     let upstream = adt_id.module(db.upcast()).krate() != krate;
-    let where_clauses = type_ctor
-        .as_generic_def()
-        .map(|generic_def| {
-            let generic_params = generics(db.upcast(), generic_def);
-            let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
-            convert_where_clauses(db, generic_def, &bound_vars)
-        })
-        .unwrap_or_else(Vec::new);
+    let where_clauses = {
+        let generic_params = generics(db.upcast(), adt_id.into());
+        let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
+        convert_where_clauses(db, adt_id.into(), &bound_vars)
+    };
     let flags = rust_ir::AdtFlags {
         upstream,
         // FIXME set fundamental and phantom_data flags correctly
@@ -548,7 +543,7 @@ fn impl_def_datum(
     let generic_params = generics(db.upcast(), impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
     let trait_ = trait_ref.trait_;
-    let impl_type = if impl_id.lookup(db.upcast()).container.module(db.upcast()).krate() == krate {
+    let impl_type = if impl_id.lookup(db.upcast()).container.krate() == krate {
         rust_ir::ImplType::Local
     } else {
         rust_ir::ImplType::External
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 3a08b67e9..b0415e8b0 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -17,7 +17,7 @@ use crate::{
     primitive::UintTy,
     traits::{Canonical, Obligation},
     AliasTy, CallableDefId, FnPointer, FnSig, GenericPredicate, InEnvironment, OpaqueTy,
-    OpaqueTyId, ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitEnvironment, TraitRef, Ty,
+    OpaqueTyId, ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitRef, Ty,
 };
 
 use super::interner::*;
@@ -536,31 +536,6 @@ where
     }
 }
 
-impl ToChalk for Arc<TraitEnvironment> {
-    type Chalk = chalk_ir::Environment<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Environment<Interner> {
-        let mut clauses = Vec::new();
-        for pred in &self.predicates {
-            if pred.is_error() {
-                // for env, we just ignore errors
-                continue;
-            }
-            let program_clause: chalk_ir::ProgramClause<Interner> =
-                pred.clone().to_chalk(db).cast(&Interner);
-            clauses.push(program_clause.into_from_env_clause(&Interner));
-        }
-        chalk_ir::Environment::new(&Interner).add_clauses(&Interner, clauses)
-    }
-
-    fn from_chalk(
-        _db: &dyn HirDatabase,
-        _env: chalk_ir::Environment<Interner>,
-    ) -> Arc<TraitEnvironment> {
-        unimplemented!()
-    }
-}
-
 impl<T: ToChalk> ToChalk for InEnvironment<T>
 where
     T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
@@ -569,19 +544,16 @@ where
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T::Chalk> {
         chalk_ir::InEnvironment {
-            environment: self.environment.to_chalk(db),
+            environment: self.environment.env.clone(),
             goal: self.value.to_chalk(db),
         }
     }
 
     fn from_chalk(
-        db: &dyn HirDatabase,
-        in_env: chalk_ir::InEnvironment<T::Chalk>,
+        _db: &dyn HirDatabase,
+        _in_env: chalk_ir::InEnvironment<T::Chalk>,
     ) -> InEnvironment<T> {
-        InEnvironment {
-            environment: from_chalk(db, in_env.environment),
-            value: from_chalk(db, in_env.goal),
-        }
+        unimplemented!()
     }
 }
 
diff --git a/crates/hir_ty/src/utils.rs b/crates/hir_ty/src/utils.rs
index 65b79df0d..7351e4e54 100644
--- a/crates/hir_ty/src/utils.rs
+++ b/crates/hir_ty/src/utils.rs
@@ -259,6 +259,6 @@ fn parent_generic_def(db: &dyn DefDatabase, def: GenericDefId) -> Option<Generic
     match container {
         AssocContainerId::ImplId(it) => Some(it.into()),
         AssocContainerId::TraitId(it) => Some(it.into()),
-        AssocContainerId::ContainerId(_) => None,
+        AssocContainerId::ModuleId(_) => None,
     }
 }
diff --git a/crates/ide/Cargo.toml b/crates/ide/Cargo.toml
index f6aaaeda4..107bd8432 100644
--- a/crates/ide/Cargo.toml
+++ b/crates/ide/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 either = "1.5.3"
 indexmap = "1.4.0"
 itertools = "0.10.0"
@@ -26,7 +27,6 @@ text_edit = { path = "../text_edit", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 ide_assists = { path = "../ide_assists", version = "0.0.0" }
 ide_ssr = { path = "../ide_ssr", version = "0.0.0" }
 ide_completion = { path = "../ide_completion", version = "0.0.0" }
@@ -36,4 +36,5 @@ ide_completion = { path = "../ide_completion", version = "0.0.0" }
 hir = { path = "../hir", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide/src/display/short_label.rs b/crates/ide/src/display/short_label.rs
index 84b8883de..2df9266b4 100644
--- a/crates/ide/src/display/short_label.rs
+++ b/crates/ide/src/display/short_label.rs
@@ -71,11 +71,7 @@ impl ShortLabel for ast::TypeAlias {
 
 impl ShortLabel for ast::Const {
     fn short_label(&self) -> Option<String> {
-        let mut new_buf = short_label_from_ty(self, self.ty(), "const ")?;
-        if let Some(expr) = self.body() {
-            format_to!(new_buf, " = {}", expr.syntax());
-        }
-        Some(new_buf)
+        short_label_from_ty(self, self.ty(), "const ")
     }
 }
 
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index a9454cfa3..ea45086ce 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,3 +1,4 @@
+use either::Either;
 use hir::{
     Adt, AsAssocItem, AssocItemContainer, FieldSource, GenericParam, HasAttrs, HasSource,
     HirDisplay, Module, ModuleDef, ModuleSource, Semantics,
@@ -11,7 +12,6 @@ use ide_db::{
 use itertools::Itertools;
 use stdx::format_to;
 use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
-use test_utils::mark;
 
 use crate::{
     display::{macro_label, ShortLabel, TryToNav},
@@ -193,8 +193,8 @@ fn runnable_action(
             ModuleDef::Function(func) => {
                 let src = func.source(sema.db)?;
                 if src.file_id != file_id.into() {
-                    mark::hit!(hover_macro_generated_struct_fn_doc_comment);
-                    mark::hit!(hover_macro_generated_struct_fn_doc_attr);
+                    cov_mark::hit!(hover_macro_generated_struct_fn_doc_comment);
+                    cov_mark::hit!(hover_macro_generated_struct_fn_doc_attr);
                     return None;
                 }
 
@@ -367,7 +367,7 @@ fn hover_for_definition(
                 .and_then(|fd| hover_for_builtin(fd, it))
                 .or_else(|| Some(Markup::fenced_block(&it.name()))),
         },
-        Definition::Local(it) => Some(Markup::fenced_block(&it.ty(db).display(db))),
+        Definition::Local(it) => hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
             impl_def.target_ty(db).as_adt().and_then(|adt| match adt {
                 Adt::Struct(it) => from_def_source(db, it, mod_path),
@@ -406,6 +406,29 @@ fn hover_for_definition(
     }
 }
 
+fn hover_for_local(it: hir::Local, db: &RootDatabase) -> Option<Markup> {
+    let ty = it.ty(db);
+    let ty = ty.display(db);
+    let is_mut = if it.is_mut(db) { "mut " } else { "" };
+    let desc = match it.source(db).value {
+        Either::Left(ident) => {
+            let name = it.name(db).unwrap();
+            let let_kw = if ident
+                .syntax()
+                .parent()
+                .map_or(false, |p| p.kind() == LET_STMT || p.kind() == CONDITION)
+            {
+                "let "
+            } else {
+                ""
+            };
+            format!("{}{}{}: {}", let_kw, is_mut, name, ty)
+        }
+        Either::Right(_) => format!("{}self: {}", is_mut, ty),
+    };
+    hover_markup(None, Some(desc), None)
+}
+
 fn hover_for_keyword(
     sema: &Semantics<RootDatabase>,
     links_in_hover: bool,
@@ -575,7 +598,7 @@ fn main() {
                 *iter*
 
                 ```rust
-                Iter<Scan<OtherStruct<OtherStruct<i32>>, |&mut u32, &u32, &mut u32| -> Option<u32>, u32>>
+                let mut iter: Iter<Scan<OtherStruct<OtherStruct<i32>>, |&mut u32, &u32, &mut u32| -> Option<u32>, u32>>
                 ```
             "#]],
         );
@@ -799,7 +822,7 @@ fn main() {
                 ```
 
                 ```rust
-                const foo: u32 = 123
+                const foo: u32
                 ```
             "#]],
         );
@@ -832,7 +855,7 @@ fn main() {
                 *zz*
 
                 ```rust
-                Test<i32, u8>
+                let zz: Test<i32, u8>
                 ```
             "#]],
         );
@@ -871,7 +894,7 @@ fn main() { let b$0ar = Some(12); }
                 *bar*
 
                 ```rust
-                Option<i32>
+                let bar: Option<i32>
                 ```
             "#]],
         );
@@ -939,7 +962,7 @@ fn main() {
                 *foo*
 
                 ```rust
-                i32
+                foo: i32
                 ```
             "#]],
         )
@@ -953,7 +976,7 @@ fn main() {
                 *foo*
 
                 ```rust
-                i32
+                foo: i32
                 ```
             "#]],
         )
@@ -967,7 +990,7 @@ fn main() {
                 *foo*
 
                 ```rust
-                i32
+                foo: i32
                 ```
             "#]],
         )
@@ -981,7 +1004,7 @@ fn main() {
                 *foo*
 
                 ```rust
-                i32
+                foo: i32
                 ```
             "#]],
         )
@@ -1001,7 +1024,7 @@ fn main() {
                 *_x*
 
                 ```rust
-                impl Deref<Target = u8> + DerefMut<Target = u8>
+                _x: impl Deref<Target = u8> + DerefMut<Target = u8>
                 ```
             "#]],
         )
@@ -1023,7 +1046,7 @@ fn main() { let foo_$0test = Thing::new(); }
                 *foo_test*
 
                 ```rust
-                Thing
+                let foo_test: Thing
                 ```
             "#]],
         )
@@ -1082,7 +1105,7 @@ fn main() {
                 ```
 
                 ```rust
-                const C: u32 = 1
+                const C: u32
                 ```
             "#]],
         )
@@ -1183,7 +1206,7 @@ fn y() {
                 *x*
 
                 ```rust
-                i32
+                let x: i32
                 ```
             "#]],
         )
@@ -1260,7 +1283,7 @@ fn foo(bar:u32) { let a = id!(ba$0r); }
                 *bar*
 
                 ```rust
-                u32
+                bar: u32
                 ```
             "#]],
         );
@@ -1278,7 +1301,7 @@ fn foo(bar:u32) { let a = id!(ba$0r); }
                 *bar*
 
                 ```rust
-                u32
+                bar: u32
                 ```
             "#]],
         );
@@ -2101,7 +2124,7 @@ pub fn fo$0o() {}
 
     #[test]
     fn test_hover_macro_generated_struct_fn_doc_comment() {
-        mark::check!(hover_macro_generated_struct_fn_doc_comment);
+        cov_mark::check!(hover_macro_generated_struct_fn_doc_comment);
 
         check(
             r#"
@@ -2139,7 +2162,7 @@ fn foo() { let bar = Bar; bar.fo$0o(); }
 
     #[test]
     fn test_hover_macro_generated_struct_fn_doc_attr() {
-        mark::check!(hover_macro_generated_struct_fn_doc_attr);
+        cov_mark::check!(hover_macro_generated_struct_fn_doc_attr);
 
         check(
             r#"
@@ -3303,7 +3326,7 @@ fn main() {
                 *f*
 
                 ```rust
-                &i32
+                f: &i32
                 ```
             "#]],
         );
@@ -3322,7 +3345,7 @@ impl Foo {
                 *self*
 
                 ```rust
-                &Foo
+                self: &Foo
                 ```
             "#]],
         );
@@ -3342,7 +3365,7 @@ impl Foo {
                 *self*
 
                 ```rust
-                Arc<Foo>
+                self: Arc<Foo>
                 ```
             "#]],
         );
@@ -3538,7 +3561,7 @@ fn foo() {
                 ```
 
                 ```rust
-                const FOO: usize = 3
+                const FOO: usize
                 ```
 
                 ---
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
index 7fcae13e0..20a920ddb 100644
--- a/crates/ide/src/join_lines.rs
+++ b/crates/ide/src/join_lines.rs
@@ -7,7 +7,7 @@ use syntax::{
     SyntaxKind::{self, USE_TREE, WHITESPACE},
     SyntaxNode, SyntaxToken, TextRange, TextSize, T,
 };
-use test_utils::mark;
+
 use text_edit::{TextEdit, TextEditBuilder};
 
 // Feature: Join Lines
@@ -60,7 +60,7 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextS
         let mut string_open_quote = false;
         if let Some(string) = ast::String::cast(token.clone()) {
             if let Some(range) = string.open_quote_text_range() {
-                mark::hit!(join_string_literal);
+                cov_mark::hit!(join_string_literal);
                 string_open_quote = range.end() == offset;
             }
         }
@@ -206,7 +206,7 @@ fn compute_ws(left: SyntaxKind, right: SyntaxKind) -> &'static str {
 #[cfg(test)]
 mod tests {
     use syntax::SourceFile;
-    use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range, mark};
+    use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
 
     use super::*;
 
@@ -786,7 +786,7 @@ fn foo() {
 
     #[test]
     fn join_string_literal() {
-        mark::check!(join_string_literal);
+        cov_mark::check!(join_string_literal);
         check_join_lines(
             r#"
 fn main() {
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index b600178ee..0a493d2f3 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -41,6 +41,7 @@ mod parent_module;
 mod references;
 mod fn_references;
 mod runnables;
+mod ssr;
 mod status;
 mod syntax_highlighting;
 mod syntax_tree;
@@ -51,6 +52,7 @@ mod doc_links;
 use std::sync::Arc;
 
 use cfg::CfgOptions;
+
 use ide_db::base_db::{
     salsa::{self, ParallelDatabase},
     CheckCanceled, Env, FileLoader, FileSet, SourceDatabase, VfsPath,
@@ -85,7 +87,7 @@ pub use crate::{
 pub use hir::{Documentation, Semantics};
 pub use ide_assists::{Assist, AssistConfig, AssistId, AssistKind};
 pub use ide_completion::{
-    CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, ImportEdit,
+    CompletionConfig, CompletionItem, CompletionItemKind, CompletionRelevance, ImportEdit,
     InsertTextFormat,
 };
 pub use ide_db::{
@@ -478,7 +480,6 @@ impl Analysis {
         position: FilePosition,
         full_import_path: &str,
         imported_name: String,
-        import_for_trait_assoc_item: bool,
     ) -> Cancelable<Vec<TextEdit>> {
         Ok(self
             .with_db(|db| {
@@ -488,7 +489,6 @@ impl Analysis {
                     position,
                     full_import_path,
                     imported_name,
-                    import_for_trait_assoc_item,
                 )
             })?
             .unwrap_or_default())
@@ -504,7 +504,11 @@ impl Analysis {
         resolve: bool,
         frange: FileRange,
     ) -> Cancelable<Vec<Assist>> {
-        self.with_db(|db| Assist::get(db, config, resolve, frange))
+        self.with_db(|db| {
+            let mut acc = Assist::get(db, config, resolve, frange);
+            ssr::add_ssr_assist(db, &mut acc, resolve, frange);
+            acc
+        })
     }
 
     /// Computes the set of diagnostics for the given file.
diff --git a/crates/ide/src/matching_brace.rs b/crates/ide/src/matching_brace.rs
index 1bfa1439d..000c412d9 100644
--- a/crates/ide/src/matching_brace.rs
+++ b/crates/ide/src/matching_brace.rs
@@ -2,7 +2,6 @@ use syntax::{
     ast::{self, AstNode},
     SourceFile, SyntaxKind, TextSize, T,
 };
-use test_utils::mark;
 
 // Feature: Matching Brace
 //
@@ -28,7 +27,7 @@ pub(crate) fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<Text
         .next()?;
     let parent = brace_token.parent();
     if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
-        mark::hit!(pipes_not_braces);
+        cov_mark::hit!(pipes_not_braces);
         return None;
     }
     let matching_kind = BRACES[brace_idx ^ 1];
@@ -63,7 +62,7 @@ mod tests {
         do_check("fn main() { $0|x: i32| x * 2;}", "fn main() { |x: i32$0| x * 2;}");
 
         {
-            mark::check!(pipes_not_braces);
+            cov_mark::check!(pipes_not_braces);
             do_check(
                 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",
                 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",
diff --git a/crates/ide/src/parent_module.rs b/crates/ide/src/parent_module.rs
index ddbaf22b7..03d71b380 100644
--- a/crates/ide/src/parent_module.rs
+++ b/crates/ide/src/parent_module.rs
@@ -5,7 +5,6 @@ use syntax::{
     algo::find_node_at_offset,
     ast::{self, AstNode},
 };
-use test_utils::mark;
 
 use crate::NavigationTarget;
 
@@ -33,7 +32,7 @@ pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<Na
             .item_list()
             .map_or(false, |it| it.syntax().text_range().contains_inclusive(position.offset))
         {
-            mark::hit!(test_resolve_parent_module_on_module_decl);
+            cov_mark::hit!(test_resolve_parent_module_on_module_decl);
             module = m.syntax().ancestors().skip(1).find_map(ast::Module::cast);
         }
     }
@@ -64,7 +63,6 @@ pub(crate) fn crate_for(db: &RootDatabase, file_id: FileId) -> Vec<CrateId> {
 #[cfg(test)]
 mod tests {
     use ide_db::base_db::FileRange;
-    use test_utils::mark;
 
     use crate::fixture;
 
@@ -92,7 +90,7 @@ $0// empty
 
     #[test]
     fn test_resolve_parent_module_on_module_decl() {
-        mark::check!(test_resolve_parent_module_on_module_decl);
+        cov_mark::check!(test_resolve_parent_module_on_module_decl);
         check(
             r#"
 //- /lib.rs
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 1919639a3..1e378279d 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -14,14 +14,14 @@ use syntax::{
     ast::{self, NameOwner},
     lex_single_syntax_kind, AstNode, SyntaxKind, SyntaxNode, T,
 };
-use test_utils::mark;
+
 use text_edit::TextEdit;
 
 use crate::{display::TryToNav, FilePosition, FileSystemEdit, RangeInfo, SourceChange, TextRange};
 
 type RenameResult<T> = Result<T, RenameError>;
 #[derive(Debug)]
-pub struct RenameError(pub(crate) String);
+pub struct RenameError(String);
 
 impl fmt::Display for RenameError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -47,16 +47,15 @@ pub(crate) fn prepare_rename(
     let sema = Semantics::new(db);
     let source_file = sema.parse(position.file_id);
     let syntax = source_file.syntax();
-    let range = match &sema
+    let name_like = sema
         .find_node_at_offset_with_descend(&syntax, position.offset)
-        .ok_or_else(|| format_err!("No references found at position"))?
-    {
+        .ok_or_else(|| format_err!("No references found at position"))?;
+    let node = match &name_like {
         ast::NameLike::Name(it) => it.syntax(),
         ast::NameLike::NameRef(it) => it.syntax(),
         ast::NameLike::Lifetime(it) => it.syntax(),
-    }
-    .text_range();
-    Ok(RangeInfo::new(range, ()))
+    };
+    Ok(RangeInfo::new(sema.original_range(node).range, ()))
 }
 
 // Feature: Rename
@@ -94,6 +93,7 @@ pub(crate) fn rename_with_semantics(
     }
 }
 
+/// Called by the client when it is about to rename a file.
 pub(crate) fn will_rename_file(
     db: &RootDatabase,
     file_id: FileId,
@@ -226,34 +226,36 @@ fn rename_reference(
         | (IdentifierKind::Ident, _)
             if def_is_lbl_or_lt =>
         {
-            mark::hit!(rename_not_a_lifetime_ident_ref);
+            cov_mark::hit!(rename_not_a_lifetime_ident_ref);
             bail!("Invalid name `{}`: not a lifetime identifier", new_name)
         }
-        (IdentifierKind::Lifetime, _) if def_is_lbl_or_lt => mark::hit!(rename_lifetime),
+        (IdentifierKind::Lifetime, _) if def_is_lbl_or_lt => cov_mark::hit!(rename_lifetime),
         (IdentifierKind::Lifetime, _) => {
-            mark::hit!(rename_not_an_ident_ref);
+            cov_mark::hit!(rename_not_an_ident_ref);
             bail!("Invalid name `{}`: not an identifier", new_name)
         }
         (IdentifierKind::ToSelf, Definition::Local(local)) if local.is_self(sema.db) => {
             // no-op
-            mark::hit!(rename_self_to_self);
+            cov_mark::hit!(rename_self_to_self);
             return Ok(SourceChange::default());
         }
         (ident_kind, Definition::Local(local)) if local.is_self(sema.db) => {
-            mark::hit!(rename_self_to_param);
+            cov_mark::hit!(rename_self_to_param);
             return rename_self_to_param(sema, local, new_name, ident_kind);
         }
         (IdentifierKind::ToSelf, Definition::Local(local)) => {
-            mark::hit!(rename_to_self);
+            cov_mark::hit!(rename_to_self);
             return rename_to_self(sema, local);
         }
         (IdentifierKind::ToSelf, _) => bail!("Invalid name `{}`: not an identifier", new_name),
-        (IdentifierKind::Ident, _) | (IdentifierKind::Underscore, _) => mark::hit!(rename_ident),
+        (IdentifierKind::Ident, _) | (IdentifierKind::Underscore, _) => {
+            cov_mark::hit!(rename_ident)
+        }
     }
 
     let usages = def.usages(sema).all();
     if !usages.is_empty() && ident_kind == IdentifierKind::Underscore {
-        mark::hit!(rename_underscore_multiple);
+        cov_mark::hit!(rename_underscore_multiple);
         bail!("Cannot rename reference to `_` as it is being referenced multiple times");
     }
     let mut source_change = SourceChange::default();
@@ -444,7 +446,7 @@ fn source_edit_from_name_ref(
             (Some(field_name), Some(init)) => {
                 if field_name == *name_ref {
                     if init.text() == new_name {
-                        mark::hit!(test_rename_field_put_init_shorthand);
+                        cov_mark::hit!(test_rename_field_put_init_shorthand);
                         // same names, we can use a shorthand here instead.
                         // we do not want to erase attributes hence this range start
                         let s = field_name.syntax().text_range().start();
@@ -453,7 +455,7 @@ fn source_edit_from_name_ref(
                     }
                 } else if init == *name_ref {
                     if field_name.text() == new_name {
-                        mark::hit!(test_rename_local_put_init_shorthand);
+                        cov_mark::hit!(test_rename_local_put_init_shorthand);
                         // same names, we can use a shorthand here instead.
                         // we do not want to erase attributes hence this range start
                         let s = field_name.syntax().text_range().start();
@@ -467,12 +469,12 @@ fn source_edit_from_name_ref(
             // FIXME: instead of splitting the shorthand, recursively trigger a rename of the
             // other name https://github.com/rust-analyzer/rust-analyzer/issues/6547
             (None, Some(_)) if matches!(def, Definition::Field(_)) => {
-                mark::hit!(test_rename_field_in_field_shorthand);
+                cov_mark::hit!(test_rename_field_in_field_shorthand);
                 let s = name_ref.syntax().text_range().start();
                 Some((TextRange::empty(s), format!("{}: ", new_name)))
             }
             (None, Some(_)) if matches!(def, Definition::Local(_)) => {
-                mark::hit!(test_rename_local_in_field_shorthand);
+                cov_mark::hit!(test_rename_local_in_field_shorthand);
                 let s = name_ref.syntax().text_range().end();
                 Some((TextRange::empty(s), format!(": {}", new_name)))
             }
@@ -486,7 +488,7 @@ fn source_edit_from_name_ref(
             (Some(field_name), Some(ast::Pat::IdentPat(pat))) if field_name == *name_ref => {
                 // field name is being renamed
                 if pat.name().map_or(false, |it| it.text() == new_name) {
-                    mark::hit!(test_rename_field_put_init_shorthand_pat);
+                    cov_mark::hit!(test_rename_field_put_init_shorthand_pat);
                     // same names, we can use a shorthand here instead/
                     // we do not want to erase attributes hence this range start
                     let s = field_name.syntax().text_range().start();
@@ -538,11 +540,13 @@ fn source_edit_from_def(
 mod tests {
     use expect_test::{expect, Expect};
     use stdx::trim_indent;
-    use test_utils::{assert_eq_text, mark};
+    use test_utils::assert_eq_text;
     use text_edit::TextEdit;
 
     use crate::{fixture, FileId};
 
+    use super::{RangeInfo, RenameError};
+
     fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
         let ra_fixture_after = &trim_indent(ra_fixture_after);
         let (analysis, position) = fixture::position(ra_fixture_before);
@@ -588,6 +592,45 @@ mod tests {
         expect.assert_debug_eq(&source_change)
     }
 
+    fn check_prepare(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let result = analysis
+            .prepare_rename(position)
+            .unwrap_or_else(|err| panic!("PrepareRename was cancelled: {}", err));
+        match result {
+            Ok(RangeInfo { range, info: () }) => {
+                let source = analysis.file_text(position.file_id).unwrap();
+                expect.assert_eq(&format!("{:?}: {}", range, &source[range]))
+            }
+            Err(RenameError(err)) => expect.assert_eq(&err),
+        };
+    }
+
+    #[test]
+    fn test_prepare_rename_namelikes() {
+        check_prepare(r"fn name$0<'lifetime>() {}", expect![[r#"3..7: name"#]]);
+        check_prepare(r"fn name<'lifetime$0>() {}", expect![[r#"8..17: 'lifetime"#]]);
+        check_prepare(r"fn name<'lifetime>() { name$0(); }", expect![[r#"23..27: name"#]]);
+    }
+
+    #[test]
+    fn test_prepare_rename_in_macro() {
+        check_prepare(
+            r"macro_rules! foo {
+    ($ident:ident) => {
+        pub struct $ident;
+    }
+}
+foo!(Foo$0);",
+            expect![[r#"83..86: Foo"#]],
+        );
+    }
+
+    #[test]
+    fn test_prepare_rename_keyword() {
+        check_prepare(r"struct$0 Foo;", expect![[r#"No references found at position"#]]);
+    }
+
     #[test]
     fn test_rename_to_underscore() {
         check("_", r#"fn main() { let i$0 = 1; }"#, r#"fn main() { let _ = 1; }"#);
@@ -627,7 +670,7 @@ mod tests {
 
     #[test]
     fn test_rename_to_invalid_identifier_lifetime() {
-        mark::check!(rename_not_an_ident_ref);
+        cov_mark::check!(rename_not_an_ident_ref);
         check(
             "'foo",
             r#"fn main() { let i$0 = 1; }"#,
@@ -637,7 +680,7 @@ mod tests {
 
     #[test]
     fn test_rename_to_invalid_identifier_lifetime2() {
-        mark::check!(rename_not_a_lifetime_ident_ref);
+        cov_mark::check!(rename_not_a_lifetime_ident_ref);
         check(
             "foo",
             r#"fn main<'a>(_: &'a$0 ()) {}"#,
@@ -647,7 +690,7 @@ mod tests {
 
     #[test]
     fn test_rename_to_underscore_invalid() {
-        mark::check!(rename_underscore_multiple);
+        cov_mark::check!(rename_underscore_multiple);
         check(
             "_",
             r#"fn main(foo$0: ()) {foo;}"#,
@@ -666,7 +709,7 @@ mod tests {
 
     #[test]
     fn test_rename_for_local() {
-        mark::check!(rename_ident);
+        cov_mark::check!(rename_ident);
         check(
             "k",
             r#"
@@ -829,7 +872,7 @@ impl Foo {
 
     #[test]
     fn test_rename_field_in_field_shorthand() {
-        mark::check!(test_rename_field_in_field_shorthand);
+        cov_mark::check!(test_rename_field_in_field_shorthand);
         check(
             "j",
             r#"
@@ -855,7 +898,7 @@ impl Foo {
 
     #[test]
     fn test_rename_local_in_field_shorthand() {
-        mark::check!(test_rename_local_in_field_shorthand);
+        cov_mark::check!(test_rename_local_in_field_shorthand);
         check(
             "j",
             r#"
@@ -1261,7 +1304,7 @@ fn foo(f: foo::Foo) {
 
     #[test]
     fn test_parameter_to_self() {
-        mark::check!(rename_to_self);
+        cov_mark::check!(rename_to_self);
         check(
             "self",
             r#"
@@ -1401,7 +1444,7 @@ impl Foo {
 
     #[test]
     fn test_owned_self_to_parameter() {
-        mark::check!(rename_self_to_param);
+        cov_mark::check!(rename_self_to_param);
         check(
             "foo",
             r#"
@@ -1454,7 +1497,7 @@ impl Foo {
 
     #[test]
     fn test_rename_field_put_init_shorthand() {
-        mark::check!(test_rename_field_put_init_shorthand);
+        cov_mark::check!(test_rename_field_put_init_shorthand);
         check(
             "bar",
             r#"
@@ -1476,7 +1519,7 @@ fn foo(bar: i32) -> Foo {
 
     #[test]
     fn test_rename_local_put_init_shorthand() {
-        mark::check!(test_rename_local_put_init_shorthand);
+        cov_mark::check!(test_rename_local_put_init_shorthand);
         check(
             "i",
             r#"
@@ -1498,7 +1541,7 @@ fn foo(i: i32) -> Foo {
 
     #[test]
     fn test_struct_field_pat_into_shorthand() {
-        mark::check!(test_rename_field_put_init_shorthand_pat);
+        cov_mark::check!(test_rename_field_put_init_shorthand_pat);
         check(
             "baz",
             r#"
@@ -1610,7 +1653,7 @@ fn foo(foo: Foo) {
 
     #[test]
     fn test_rename_lifetimes() {
-        mark::check!(rename_lifetime);
+        cov_mark::check!(rename_lifetime);
         check(
             "'yeeee",
             r#"
@@ -1698,7 +1741,7 @@ fn foo<'a>() -> &'a () {
 
     #[test]
     fn test_self_to_self() {
-        mark::check!(rename_self_to_self);
+        cov_mark::check!(rename_self_to_self);
         check(
             "self",
             r#"
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 65f60891e..280565563 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -9,7 +9,6 @@ use syntax::{
     ast::{self, AstNode, AttrsOwner},
     match_ast, SyntaxNode,
 };
-use test_utils::mark;
 
 use crate::{
     display::{ToNav, TryToNav},
@@ -130,7 +129,9 @@ fn runnables_mod(sema: &Semantics<RootDatabase>, acc: &mut Vec<Runnable>, module
         if let hir::ModuleDef::Module(submodule) = def {
             match submodule.definition_source(sema.db).value {
                 hir::ModuleSource::Module(_) => runnables_mod(sema, acc, submodule),
-                hir::ModuleSource::SourceFile(_) => mark::hit!(dont_recurse_in_outline_submodules),
+                hir::ModuleSource::SourceFile(_) => {
+                    cov_mark::hit!(dont_recurse_in_outline_submodules)
+                }
                 hir::ModuleSource::BlockExpr(_) => {} // inner items aren't runnable
             }
         }
@@ -328,7 +329,6 @@ fn has_test_function_or_multiple_test_submodules(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::fixture;
 
@@ -1056,7 +1056,7 @@ mod tests {
 
     #[test]
     fn dont_recurse_in_outline_submodules() {
-        mark::check!(dont_recurse_in_outline_submodules);
+        cov_mark::check!(dont_recurse_in_outline_submodules);
         check(
             r#"
 //- /lib.rs
diff --git a/crates/ide/src/ssr.rs b/crates/ide/src/ssr.rs
new file mode 100644
index 000000000..f3638d928
--- /dev/null
+++ b/crates/ide/src/ssr.rs
@@ -0,0 +1,259 @@
+//! This module provides an SSR assist. It is not desirable to include this
+//! assist in ide_assists because that would require the ide_assists crate
+//! depend on the ide_ssr crate.
+
+use ide_assists::{Assist, AssistId, AssistKind, GroupLabel};
+use ide_db::{base_db::FileRange, label::Label, source_change::SourceChange, RootDatabase};
+
+pub(crate) fn add_ssr_assist(
+    db: &RootDatabase,
+    base: &mut Vec<Assist>,
+    resolve: bool,
+    frange: FileRange,
+) -> Option<()> {
+    let (match_finder, comment_range) = ide_ssr::ssr_from_comment(db, frange)?;
+
+    let (source_change_for_file, source_change_for_workspace) = if resolve {
+        let edits = match_finder.edits();
+
+        let source_change_for_file = {
+            let text_edit_for_file = edits.get(&frange.file_id).cloned().unwrap_or_default();
+            SourceChange::from_text_edit(frange.file_id, text_edit_for_file)
+        };
+
+        let source_change_for_workspace = SourceChange::from(match_finder.edits());
+
+        (Some(source_change_for_file), Some(source_change_for_workspace))
+    } else {
+        (None, None)
+    };
+
+    let assists = vec![
+        ("Apply SSR in file", source_change_for_file),
+        ("Apply SSR in workspace", source_change_for_workspace),
+    ];
+
+    for (label, source_change) in assists.into_iter() {
+        let assist = Assist {
+            id: AssistId("ssr", AssistKind::RefactorRewrite),
+            label: Label::new(label),
+            group: Some(GroupLabel("Apply SSR".into())),
+            target: comment_range,
+            source_change,
+        };
+
+        base.push(assist);
+    }
+    Some(())
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use expect_test::expect;
+    use ide_assists::Assist;
+    use ide_db::{
+        base_db::{fixture::WithFixture, salsa::Durability, FileRange},
+        symbol_index::SymbolsDatabase,
+        RootDatabase,
+    };
+    use rustc_hash::FxHashSet;
+
+    use super::add_ssr_assist;
+
+    fn get_assists(ra_fixture: &str, resolve: bool) -> Vec<Assist> {
+        let (mut db, file_id, range_or_offset) = RootDatabase::with_range_or_offset(ra_fixture);
+        let mut local_roots = FxHashSet::default();
+        local_roots.insert(ide_db::base_db::fixture::WORKSPACE);
+        db.set_local_roots_with_durability(Arc::new(local_roots), Durability::HIGH);
+
+        let mut assists = vec![];
+
+        add_ssr_assist(
+            &db,
+            &mut assists,
+            resolve,
+            FileRange { file_id, range: range_or_offset.into() },
+        );
+
+        assists
+    }
+
+    #[test]
+    fn not_applicable_comment_not_ssr() {
+        let ra_fixture = r#"
+            //- /lib.rs
+
+            // This is foo $0
+            fn foo() {}
+            "#;
+        let resolve = true;
+
+        let assists = get_assists(ra_fixture, resolve);
+
+        assert_eq!(0, assists.len());
+    }
+
+    #[test]
+    fn resolve_edits_true() {
+        let resolve = true;
+        let assists = get_assists(
+            r#"
+            //- /lib.rs
+            mod bar;
+
+            // 2 ==>> 3$0
+            fn foo() { 2 }
+
+            //- /bar.rs
+            fn bar() { 2 }
+            "#,
+            resolve,
+        );
+
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let apply_in_file_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "ssr",
+                    RefactorRewrite,
+                ),
+                label: "Apply SSR in file",
+                group: Some(
+                    GroupLabel(
+                        "Apply SSR",
+                    ),
+                ),
+                target: 10..21,
+                source_change: Some(
+                    SourceChange {
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "3",
+                                        delete: 33..34,
+                                    },
+                                ],
+                            },
+                        },
+                        file_system_edits: [],
+                        is_snippet: false,
+                    },
+                ),
+            }
+        "#]]
+        .assert_debug_eq(&apply_in_file_assist);
+
+        let apply_in_workspace_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "ssr",
+                    RefactorRewrite,
+                ),
+                label: "Apply SSR in workspace",
+                group: Some(
+                    GroupLabel(
+                        "Apply SSR",
+                    ),
+                ),
+                target: 10..21,
+                source_change: Some(
+                    SourceChange {
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "3",
+                                        delete: 33..34,
+                                    },
+                                ],
+                            },
+                            FileId(
+                                1,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "3",
+                                        delete: 11..12,
+                                    },
+                                ],
+                            },
+                        },
+                        file_system_edits: [],
+                        is_snippet: false,
+                    },
+                ),
+            }
+        "#]]
+        .assert_debug_eq(&apply_in_workspace_assist);
+    }
+
+    #[test]
+    fn resolve_edits_false() {
+        let resolve = false;
+        let assists = get_assists(
+            r#"
+            //- /lib.rs
+            mod bar;
+
+            // 2 ==>> 3$0
+            fn foo() { 2 }
+
+            //- /bar.rs
+            fn bar() { 2 }
+            "#,
+            resolve,
+        );
+
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let apply_in_file_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "ssr",
+                    RefactorRewrite,
+                ),
+                label: "Apply SSR in file",
+                group: Some(
+                    GroupLabel(
+                        "Apply SSR",
+                    ),
+                ),
+                target: 10..21,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&apply_in_file_assist);
+
+        let apply_in_workspace_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "ssr",
+                    RefactorRewrite,
+                ),
+                label: "Apply SSR in workspace",
+                group: Some(
+                    GroupLabel(
+                        "Apply SSR",
+                    ),
+                ),
+                target: 10..21,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&apply_in_workspace_assist);
+    }
+}
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 24fcbb584..b0cfdd8b7 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -330,10 +330,11 @@ fn highlight_def(db: &RootDatabase, def: Definition) -> Highlight {
                 HlTag::Symbol(SymbolKind::Local)
             };
             let mut h = Highlight::new(tag);
-            if local.is_mut(db) || local.ty(db).is_mutable_reference() {
+            let ty = local.ty(db);
+            if local.is_mut(db) || ty.is_mutable_reference() {
                 h |= HlMod::Mutable;
             }
-            if local.ty(db).as_callable(db).is_some() || local.ty(db).impls_fnonce(db) {
+            if ty.as_callable(db).is_some() || ty.impls_fnonce(db) {
                 h |= HlMod::Callable;
             }
             return h;
diff --git a/crates/ide/src/typing/on_enter.rs b/crates/ide/src/typing/on_enter.rs
index 63cd51b69..978c479de 100644
--- a/crates/ide/src/typing/on_enter.rs
+++ b/crates/ide/src/typing/on_enter.rs
@@ -9,7 +9,7 @@ use syntax::{
     SyntaxKind::*,
     SyntaxToken, TextRange, TextSize, TokenAtOffset,
 };
-use test_utils::mark;
+
 use text_edit::TextEdit;
 
 // Feature: On Enter
@@ -55,7 +55,7 @@ pub(crate) fn on_enter(db: &RootDatabase, position: FilePosition) -> Option<Text
     // Continuing single-line non-doc comments (like this one :) ) is annoying
     if prefix == "//" && comment_range.end() == position.offset {
         if comment.text().ends_with(' ') {
-            mark::hit!(continues_end_of_line_comment_with_space);
+            cov_mark::hit!(continues_end_of_line_comment_with_space);
             remove_trailing_whitespace = true;
         } else if !followed_by_comment(&comment) {
             return None;
@@ -109,7 +109,7 @@ fn node_indent(file: &SourceFile, token: &SyntaxToken) -> Option<SmolStr> {
 #[cfg(test)]
 mod tests {
     use stdx::trim_indent;
-    use test_utils::{assert_eq_text, mark};
+    use test_utils::assert_eq_text;
 
     use crate::fixture;
 
@@ -238,7 +238,7 @@ fn main() {
 
     #[test]
     fn continues_end_of_line_comment_with_space() {
-        mark::check!(continues_end_of_line_comment_with_space);
+        cov_mark::check!(continues_end_of_line_comment_with_space);
         do_check(
             r#"
 fn main() {
diff --git a/crates/ide_assists/Cargo.toml b/crates/ide_assists/Cargo.toml
index a34bdd6c3..dd9aa27c6 100644
--- a/crates/ide_assists/Cargo.toml
+++ b/crates/ide_assists/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 rustc-hash = "1.1.0"
 itertools = "0.10.0"
 either = "1.6.1"
@@ -20,7 +21,7 @@ text_edit = { path = "../text_edit", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 hir = { path = "../hir", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide_assists/src/handlers/add_turbo_fish.rs b/crates/ide_assists/src/handlers/add_turbo_fish.rs
index a08b55ebb..ee879c151 100644
--- a/crates/ide_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ide_assists/src/handlers/add_turbo_fish.rs
@@ -1,6 +1,5 @@
 use ide_db::defs::{Definition, NameRefClass};
 use syntax::{ast, AstNode, SyntaxKind, T};
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -30,13 +29,13 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
         if arg_list.args().count() > 0 {
             return None;
         }
-        mark::hit!(add_turbo_fish_after_call);
-        mark::hit!(add_type_ascription_after_call);
+        cov_mark::hit!(add_turbo_fish_after_call);
+        cov_mark::hit!(add_type_ascription_after_call);
         arg_list.l_paren_token()?.prev_token().filter(|it| it.kind() == SyntaxKind::IDENT)
     })?;
     let next_token = ident.next_token()?;
     if next_token.kind() == T![::] {
-        mark::hit!(add_turbo_fish_one_fish_is_enough);
+        cov_mark::hit!(add_turbo_fish_one_fish_is_enough);
         return None;
     }
     let name_ref = ast::NameRef::cast(ident.parent())?;
@@ -50,24 +49,31 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     };
     let generics = hir::GenericDef::Function(fun).params(ctx.sema.db);
     if generics.is_empty() {
-        mark::hit!(add_turbo_fish_non_generic);
+        cov_mark::hit!(add_turbo_fish_non_generic);
         return None;
     }
 
     if let Some(let_stmt) = ctx.find_node_at_offset::<ast::LetStmt>() {
         if let_stmt.colon_token().is_none() {
             let type_pos = let_stmt.pat()?.syntax().last_token()?.text_range().end();
+            let semi_pos = let_stmt.syntax().last_token()?.text_range().end();
+
             acc.add(
                 AssistId("add_type_ascription", AssistKind::RefactorRewrite),
                 "Add `: _` before assignment operator",
                 ident.text_range(),
-                |builder| match ctx.config.snippet_cap {
-                    Some(cap) => builder.insert_snippet(cap, type_pos, ": ${0:_}"),
-                    None => builder.insert(type_pos, ": _"),
+                |builder| {
+                    if let_stmt.semicolon_token().is_none() {
+                        builder.insert(semi_pos, ";");
+                    }
+                    match ctx.config.snippet_cap {
+                        Some(cap) => builder.insert_snippet(cap, type_pos, ": ${0:_}"),
+                        None => builder.insert(type_pos, ": _"),
+                    }
                 },
             )?
         } else {
-            mark::hit!(add_type_ascription_already_typed);
+            cov_mark::hit!(add_type_ascription_already_typed);
         }
     }
 
@@ -87,7 +93,6 @@ mod tests {
     use crate::tests::{check_assist, check_assist_by_label, check_assist_not_applicable};
 
     use super::*;
-    use test_utils::mark;
 
     #[test]
     fn add_turbo_fish_function() {
@@ -110,7 +115,7 @@ fn main() {
 
     #[test]
     fn add_turbo_fish_after_call() {
-        mark::check!(add_turbo_fish_after_call);
+        cov_mark::check!(add_turbo_fish_after_call);
         check_assist(
             add_turbo_fish,
             r#"
@@ -155,7 +160,7 @@ fn main() {
 
     #[test]
     fn add_turbo_fish_one_fish_is_enough() {
-        mark::check!(add_turbo_fish_one_fish_is_enough);
+        cov_mark::check!(add_turbo_fish_one_fish_is_enough);
         check_assist_not_applicable(
             add_turbo_fish,
             r#"
@@ -169,7 +174,7 @@ fn main() {
 
     #[test]
     fn add_turbo_fish_non_generic() {
-        mark::check!(add_turbo_fish_non_generic);
+        cov_mark::check!(add_turbo_fish_non_generic);
         check_assist_not_applicable(
             add_turbo_fish,
             r#"
@@ -203,7 +208,7 @@ fn main() {
 
     #[test]
     fn add_type_ascription_after_call() {
-        mark::check!(add_type_ascription_after_call);
+        cov_mark::check!(add_type_ascription_after_call);
         check_assist_by_label(
             add_turbo_fish,
             r#"
@@ -250,7 +255,7 @@ fn main() {
 
     #[test]
     fn add_type_ascription_already_typed() {
-        mark::check!(add_type_ascription_already_typed);
+        cov_mark::check!(add_type_ascription_already_typed);
         check_assist(
             add_turbo_fish,
             r#"
@@ -267,4 +272,24 @@ fn main() {
 "#,
         );
     }
+
+    #[test]
+    fn add_type_ascription_append_semicolon() {
+        check_assist_by_label(
+            add_turbo_fish,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    let x = make$0()
+}
+"#,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    let x: ${0:_} = make();
+}
+"#,
+            "Add `: _` before assignment operator",
+        );
+    }
 }
diff --git a/crates/ide_assists/src/handlers/apply_demorgan.rs b/crates/ide_assists/src/handlers/apply_demorgan.rs
index 128b1eb56..a1c339603 100644
--- a/crates/ide_assists/src/handlers/apply_demorgan.rs
+++ b/crates/ide_assists/src/handlers/apply_demorgan.rs
@@ -1,5 +1,4 @@
 use syntax::ast::{self, AstNode};
-use test_utils::mark;
 
 use crate::{utils::invert_boolean_expression, AssistContext, AssistId, AssistKind, Assists};
 
@@ -64,10 +63,10 @@ pub(crate) fn apply_demorgan(acc: &mut Assists, ctx: &AssistContext) -> Option<(
                 edit.replace(lhs_range, not_lhs.syntax().text());
                 edit.replace(rhs_range, not_rhs.syntax().text());
                 if let Some(neg_expr) = neg_expr {
-                    mark::hit!(demorgan_double_negation);
+                    cov_mark::hit!(demorgan_double_negation);
                     edit.replace(neg_expr.op_token().unwrap().text_range(), "");
                 } else {
-                    mark::hit!(demorgan_double_parens);
+                    cov_mark::hit!(demorgan_double_parens);
                     edit.replace(paren_expr.l_paren_token().unwrap().text_range(), "!(");
                 }
             } else {
@@ -90,7 +89,6 @@ fn opposite_logic_op(kind: ast::BinOp) -> Option<&'static str> {
 #[cfg(test)]
 mod tests {
     use ide_db::helpers::FamousDefs;
-    use test_utils::mark;
 
     use super::*;
 
@@ -188,13 +186,13 @@ fn f() {
 
     #[test]
     fn demorgan_doesnt_double_negation() {
-        mark::check!(demorgan_double_negation);
+        cov_mark::check!(demorgan_double_negation);
         check_assist(apply_demorgan, "fn f() { !(x ||$0 x) }", "fn f() { (!x && !x) }")
     }
 
     #[test]
     fn demorgan_doesnt_double_parens() {
-        mark::check!(demorgan_double_parens);
+        cov_mark::check!(demorgan_double_parens);
         check_assist(apply_demorgan, "fn f() { (x ||$0 x) }", "fn f() { !(!x && !x) }")
     }
 }
diff --git a/crates/ide_assists/src/handlers/auto_import.rs b/crates/ide_assists/src/handlers/auto_import.rs
index dc38f90e9..7019039b9 100644
--- a/crates/ide_assists/src/handlers/auto_import.rs
+++ b/crates/ide_assists/src/handlers/auto_import.rs
@@ -90,17 +90,17 @@ pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     }
 
     let range = ctx.sema.original_range(&syntax_under_caret).range;
-    let group = import_group_message(import_assets.import_candidate());
+    let group_label = group_label(import_assets.import_candidate());
     let scope = ImportScope::find_insert_use_container(&syntax_under_caret, &ctx.sema)?;
-    for (import, _) in proposed_imports {
+    for import in proposed_imports {
         acc.add_group(
-            &group,
+            &group_label,
             AssistId("auto_import", AssistKind::QuickFix),
-            format!("Import `{}`", &import),
+            format!("Import `{}`", import.import_path),
             range,
             |builder| {
                 let rewriter =
-                    insert_use(&scope, mod_path_to_ast(&import), ctx.config.insert_use.merge);
+                    insert_use(&scope, mod_path_to_ast(&import.import_path), ctx.config.insert_use);
                 builder.rewrite(rewriter);
             },
         );
@@ -122,14 +122,14 @@ pub(super) fn find_importable_node(ctx: &AssistContext) -> Option<(ImportAssets,
     }
 }
 
-fn import_group_message(import_candidate: &ImportCandidate) -> GroupLabel {
+fn group_label(import_candidate: &ImportCandidate) -> GroupLabel {
     let name = match import_candidate {
         ImportCandidate::Path(candidate) => format!("Import {}", candidate.name.text()),
         ImportCandidate::TraitAssocItem(candidate) => {
-            format!("Import a trait for item {}", candidate.name.text())
+            format!("Import a trait for item {}", candidate.assoc_item_name.text())
         }
         ImportCandidate::TraitMethod(candidate) => {
-            format!("Import a trait for method {}", candidate.name.text())
+            format!("Import a trait for method {}", candidate.assoc_item_name.text())
         }
     };
     GroupLabel(name)
@@ -222,41 +222,6 @@ mod tests {
     }
 
     #[test]
-    fn auto_imports_are_merged() {
-        check_assist(
-            auto_import,
-            r"
-            use PubMod::PubStruct1;
-
-            struct Test {
-                test: Pub$0Struct2<u8>,
-            }
-
-            pub mod PubMod {
-                pub struct PubStruct1;
-                pub struct PubStruct2<T> {
-                    _t: T,
-                }
-            }
-            ",
-            r"
-            use PubMod::{PubStruct1, PubStruct2};
-
-            struct Test {
-                test: PubStruct2<u8>,
-            }
-
-            pub mod PubMod {
-                pub struct PubStruct1;
-                pub struct PubStruct2<T> {
-                    _t: T,
-                }
-            }
-            ",
-        );
-    }
-
-    #[test]
     fn applicable_when_found_multiple_imports() {
         check_assist(
             auto_import,
diff --git a/crates/ide_assists/src/handlers/change_visibility.rs b/crates/ide_assists/src/handlers/change_visibility.rs
index ac8c44124..ec99a5505 100644
--- a/crates/ide_assists/src/handlers/change_visibility.rs
+++ b/crates/ide_assists/src/handlers/change_visibility.rs
@@ -4,7 +4,6 @@ use syntax::{
     SyntaxKind::{CONST, ENUM, FN, MODULE, STATIC, STRUCT, TRAIT, TYPE_ALIAS, VISIBILITY},
     T,
 };
-use test_utils::mark;
 
 use crate::{utils::vis_offset, AssistContext, AssistId, AssistKind, Assists};
 
@@ -56,7 +55,7 @@ fn add_vis(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     } else if let Some(field_name) = ctx.find_node_at_offset::<ast::Name>() {
         let field = field_name.syntax().ancestors().find_map(ast::RecordField::cast)?;
         if field.name()? != field_name {
-            mark::hit!(change_visibility_field_false_positive);
+            cov_mark::hit!(change_visibility_field_false_positive);
             return None;
         }
         if field.visibility().is_some() {
@@ -110,8 +109,6 @@ fn change_vis(acc: &mut Assists, vis: ast::Visibility) -> Option<()> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
 
     use super::*;
@@ -139,7 +136,7 @@ mod tests {
 
     #[test]
     fn change_visibility_field_false_positive() {
-        mark::check!(change_visibility_field_false_positive);
+        cov_mark::check!(change_visibility_field_false_positive);
         check_assist_not_applicable(
             change_visibility,
             r"struct S { field: [(); { let $0x = ();}] }",
diff --git a/crates/ide_assists/src/handlers/convert_iter_for_each_to_for.rs b/crates/ide_assists/src/handlers/convert_iter_for_each_to_for.rs
new file mode 100644
index 000000000..4e75a7b14
--- /dev/null
+++ b/crates/ide_assists/src/handlers/convert_iter_for_each_to_for.rs
@@ -0,0 +1,248 @@
+use ide_db::helpers::FamousDefs;
+use syntax::{
+    ast::{self, edit::AstNodeEdit, make, ArgListOwner},
+    AstNode,
+};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: convert_iter_for_each_to_for
+//
+// Converts an Iterator::for_each function into a for loop.
+//
+// ```
+// # //- /lib.rs crate:core
+// # pub mod iter { pub mod traits { pub mod iterator { pub trait Iterator {} } } }
+// # pub struct SomeIter;
+// # impl self::iter::traits::iterator::Iterator for SomeIter {}
+// # //- /lib.rs crate:main deps:core
+// # use core::SomeIter;
+// fn main() {
+//     let iter = SomeIter;
+//     iter.for_each$0(|(x, y)| {
+//         println!("x: {}, y: {}", x, y);
+//     });
+// }
+// ```
+// ->
+// ```
+// # use core::SomeIter;
+// fn main() {
+//     let iter = SomeIter;
+//     for (x, y) in iter {
+//         println!("x: {}, y: {}", x, y);
+//     }
+// }
+// ```
+
+pub(crate) fn convert_iter_for_each_to_for(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let method = ctx.find_node_at_offset::<ast::MethodCallExpr>()?;
+
+    let closure = match method.arg_list()?.args().next()? {
+        ast::Expr::ClosureExpr(expr) => expr,
+        _ => return None,
+    };
+
+    let (method, receiver) = validate_method_call_expr(ctx, method)?;
+
+    let param_list = closure.param_list()?;
+    let param = param_list.params().next()?.pat()?;
+    let body = closure.body()?;
+
+    let stmt = method.syntax().parent().and_then(ast::ExprStmt::cast);
+    let syntax = stmt.as_ref().map_or(method.syntax(), |stmt| stmt.syntax());
+
+    acc.add(
+        AssistId("convert_iter_for_each_to_for", AssistKind::RefactorRewrite),
+        "Replace this `Iterator::for_each` with a for loop",
+        syntax.text_range(),
+        |builder| {
+            let indent = stmt.as_ref().map_or(method.indent_level(), |stmt| stmt.indent_level());
+
+            let block = match body {
+                ast::Expr::BlockExpr(block) => block,
+                _ => make::block_expr(Vec::new(), Some(body)),
+            }
+            .reset_indent()
+            .indent(indent);
+
+            let expr_for_loop = make::expr_for_loop(param, receiver, block);
+            builder.replace(syntax.text_range(), expr_for_loop.syntax().text())
+        },
+    )
+}
+
+fn validate_method_call_expr(
+    ctx: &AssistContext,
+    expr: ast::MethodCallExpr,
+) -> Option<(ast::Expr, ast::Expr)> {
+    let name_ref = expr.name_ref()?;
+    if name_ref.syntax().text_range().intersect(ctx.frange.range).is_none()
+        || name_ref.text() != "for_each"
+    {
+        return None;
+    }
+
+    let sema = &ctx.sema;
+
+    let receiver = expr.receiver()?;
+    let expr = ast::Expr::MethodCallExpr(expr);
+
+    let it_type = sema.type_of_expr(&receiver)?;
+    let module = sema.scope(receiver.syntax()).module()?;
+    let krate = module.krate();
+
+    let iter_trait = FamousDefs(sema, Some(krate)).core_iter_Iterator()?;
+    it_type.impls_trait(sema.db, iter_trait, &[]).then(|| (expr, receiver))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{self, check_assist};
+
+    use super::*;
+
+    const EMPTY_ITER_FIXTURE: &'static str = r"
+//- /lib.rs deps:core crate:empty_iter
+pub struct EmptyIter;
+impl Iterator for EmptyIter {
+    type Item = usize;
+    fn next(&mut self) -> Option<Self::Item> { None }
+}
+pub struct Empty;
+impl Empty {
+    pub fn iter(&self) -> EmptyIter { EmptyIter }
+}
+";
+
+    fn check_assist_with_fixtures(before: &str, after: &str) {
+        let before = &format!(
+            "//- /main.rs crate:main deps:core,empty_iter{}{}{}",
+            before,
+            EMPTY_ITER_FIXTURE,
+            FamousDefs::FIXTURE,
+        );
+        check_assist(convert_iter_for_each_to_for, before, after);
+    }
+
+    fn check_assist_not_applicable(before: &str) {
+        let before = &format!(
+            "//- /main.rs crate:main deps:core,empty_iter{}{}{}",
+            before,
+            EMPTY_ITER_FIXTURE,
+            FamousDefs::FIXTURE,
+        );
+        tests::check_assist_not_applicable(convert_iter_for_each_to_for, before);
+    }
+
+    #[test]
+    fn test_for_each_in_method_stmt() {
+        check_assist_with_fixtures(
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    x.iter().$0for_each(|(x, y)| {
+        println!("x: {}, y: {}", x, y);
+    });
+}"#,
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    for (x, y) in x.iter() {
+        println!("x: {}, y: {}", x, y);
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_for_each_in_method() {
+        check_assist_with_fixtures(
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    x.iter().$0for_each(|(x, y)| {
+        println!("x: {}, y: {}", x, y);
+    })
+}"#,
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    for (x, y) in x.iter() {
+        println!("x: {}, y: {}", x, y);
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_for_each_in_iter_stmt() {
+        check_assist_with_fixtures(
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty.iter();
+    x.$0for_each(|(x, y)| {
+        println!("x: {}, y: {}", x, y);
+    });
+}"#,
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty.iter();
+    for (x, y) in x {
+        println!("x: {}, y: {}", x, y);
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_for_each_without_braces_stmt() {
+        check_assist_with_fixtures(
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    x.iter().$0for_each(|(x, y)| println!("x: {}, y: {}", x, y));
+}"#,
+            r#"
+use empty_iter::*;
+fn main() {
+    let x = Empty;
+    for (x, y) in x.iter() {
+        println!("x: {}, y: {}", x, y)
+    }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_for_each_not_applicable() {
+        check_assist_not_applicable(
+            r#"
+fn main() {
+    ().$0for_each(|x| println!("{}", x));
+}"#,
+        )
+    }
+
+    #[test]
+    fn test_for_each_not_applicable_invalid_cursor_pos() {
+        check_assist_not_applicable(
+            r#"
+use empty_iter::*;
+fn main() {
+    Empty.iter().for_each(|(x, y)| $0println!("x: {}, y: {}", x, y));
+}"#,
+        )
+    }
+}
diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index 8779d8bd1..dd4501709 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -20,7 +20,6 @@ use syntax::{
     SyntaxKind::{self, BLOCK_EXPR, BREAK_EXPR, COMMENT, PATH_EXPR, RETURN_EXPR},
     SyntaxNode, SyntaxToken, TextRange, TextSize, TokenAtOffset, WalkEvent, T,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -59,7 +58,7 @@ pub(crate) fn extract_function(acc: &mut Assists, ctx: &AssistContext) -> Option
 
     let node = ctx.covering_element();
     if node.kind() == COMMENT {
-        mark::hit!(extract_function_in_comment_is_not_applicable);
+        cov_mark::hit!(extract_function_in_comment_is_not_applicable);
         return None;
     }
 
@@ -197,14 +196,14 @@ fn external_control_flow(ctx: &AssistContext, body: &FunctionBody) -> Option<Con
                 if let Some(kind) = expr_err_kind(&expr, ctx) {
                     Some(FlowKind::TryReturn { expr, kind })
                 } else {
-                    mark::hit!(external_control_flow_try_and_return_non_err);
+                    cov_mark::hit!(external_control_flow_try_and_return_non_err);
                     return None;
                 }
             }
             None => return None,
         },
         (Some(_), _, _, _) => {
-            mark::hit!(external_control_flow_try_and_bc);
+            cov_mark::hit!(external_control_flow_try_and_bc);
             return None;
         }
         (None, Some(r), None, None) => match r.expr() {
@@ -212,11 +211,11 @@ fn external_control_flow(ctx: &AssistContext, body: &FunctionBody) -> Option<Con
             None => Some(FlowKind::Return),
         },
         (None, Some(_), _, _) => {
-            mark::hit!(external_control_flow_return_and_bc);
+            cov_mark::hit!(external_control_flow_return_and_bc);
             return None;
         }
         (None, None, Some(_), Some(_)) => {
-            mark::hit!(external_control_flow_break_and_continue);
+            cov_mark::hit!(external_control_flow_break_and_continue);
             return None;
         }
         (None, None, Some(b), None) => match b.expr() {
@@ -1837,7 +1836,7 @@ fn $0fun_name(n: u32) -> u32 {
 
     #[test]
     fn in_comment_is_not_applicable() {
-        mark::check!(extract_function_in_comment_is_not_applicable);
+        cov_mark::check!(extract_function_in_comment_is_not_applicable);
         check_assist_not_applicable(extract_function, r"fn main() { 1 + /* $0comment$0 */ 1; }");
     }
 
@@ -2822,7 +2821,7 @@ fn $0fun_name(n: i32) -> Result<i32, i64> {
 
     #[test]
     fn break_and_continue() {
-        mark::check!(external_control_flow_break_and_continue);
+        cov_mark::check!(external_control_flow_break_and_continue);
         check_assist_not_applicable(
             extract_function,
             r##"
@@ -2842,7 +2841,7 @@ fn foo() {
 
     #[test]
     fn return_and_break() {
-        mark::check!(external_control_flow_return_and_bc);
+        cov_mark::check!(external_control_flow_return_and_bc);
         check_assist_not_applicable(
             extract_function,
             r##"
@@ -3341,7 +3340,7 @@ fn $0fun_name() -> Result<i32, i64> {
 
     #[test]
     fn try_and_break() {
-        mark::check!(external_control_flow_try_and_bc);
+        cov_mark::check!(external_control_flow_try_and_bc);
         check_assist_not_applicable(
             extract_function,
             r##"
@@ -3363,7 +3362,7 @@ fn foo() -> Option<()> {
 
     #[test]
     fn try_and_return_ok() {
-        mark::check!(external_control_flow_try_and_return_non_err);
+        cov_mark::check!(external_control_flow_try_and_return_non_err);
         check_assist_not_applicable(
             extract_function,
             r##"
diff --git a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
index 5c7678b53..335e0ed95 100644
--- a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -1,7 +1,7 @@
 use std::iter;
 
 use either::Either;
-use hir::{AsName, Module, ModuleDef, Name, Variant};
+use hir::{Module, ModuleDef, Name, Variant};
 use ide_db::{
     defs::Definition,
     helpers::{
@@ -133,7 +133,7 @@ fn existing_definition(db: &RootDatabase, variant_name: &ast::Name, variant: &Va
             ),
             _ => false,
         })
-        .any(|(name, _)| name == variant_name.as_name())
+        .any(|(name, _)| name.to_string() == variant_name.to_string())
 }
 
 fn insert_import(
@@ -154,7 +154,7 @@ fn insert_import(
         mod_path.pop_segment();
         mod_path.push_segment(variant_hir_name.clone());
         let scope = ImportScope::find_insert_use_container(scope_node, &ctx.sema)?;
-        *rewriter += insert_use(&scope, mod_path_to_ast(&mod_path), ctx.config.insert_use.merge);
+        *rewriter += insert_use(&scope, mod_path_to_ast(&mod_path), ctx.config.insert_use);
     }
     Some(())
 }
diff --git a/crates/ide_assists/src/handlers/extract_variable.rs b/crates/ide_assists/src/handlers/extract_variable.rs
index 312ac7ac4..7a32483dc 100644
--- a/crates/ide_assists/src/handlers/extract_variable.rs
+++ b/crates/ide_assists/src/handlers/extract_variable.rs
@@ -6,7 +6,6 @@ use syntax::{
     },
     SyntaxNode,
 };
-use test_utils::mark;
 
 use crate::{utils::suggest_name, AssistContext, AssistId, AssistKind, Assists};
 
@@ -32,7 +31,7 @@ pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option
     }
     let node = ctx.covering_element();
     if node.kind() == COMMENT {
-        mark::hit!(extract_var_in_comment_is_not_applicable);
+        cov_mark::hit!(extract_var_in_comment_is_not_applicable);
         return None;
     }
     let to_extract = node.ancestors().find_map(valid_target_expr)?;
@@ -69,7 +68,7 @@ pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option
             format_to!(buf, "{}", to_extract.syntax());
 
             if let Anchor::Replace(stmt) = anchor {
-                mark::hit!(test_extract_var_expr_stmt);
+                cov_mark::hit!(test_extract_var_expr_stmt);
                 if stmt.semicolon_token().is_none() {
                     buf.push_str(";");
                 }
@@ -142,7 +141,7 @@ impl Anchor {
                 node.parent().and_then(ast::BlockExpr::cast).and_then(|it| it.tail_expr())
             {
                 if expr.syntax() == &node {
-                    mark::hit!(test_extract_var_last_expr);
+                    cov_mark::hit!(test_extract_var_last_expr);
                     return Some(Anchor::Before(node));
                 }
             }
@@ -175,8 +174,6 @@ impl Anchor {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
 
     use super::*;
@@ -199,13 +196,13 @@ fn foo() {
 
     #[test]
     fn extract_var_in_comment_is_not_applicable() {
-        mark::check!(extract_var_in_comment_is_not_applicable);
+        cov_mark::check!(extract_var_in_comment_is_not_applicable);
         check_assist_not_applicable(extract_variable, "fn main() { 1 + /* $0comment$0 */ 1; }");
     }
 
     #[test]
     fn test_extract_var_expr_stmt() {
-        mark::check!(test_extract_var_expr_stmt);
+        cov_mark::check!(test_extract_var_expr_stmt);
         check_assist(
             extract_variable,
             r#"
@@ -250,7 +247,7 @@ fn foo() {
 
     #[test]
     fn test_extract_var_last_expr() {
-        mark::check!(test_extract_var_last_expr);
+        cov_mark::check!(test_extract_var_last_expr);
         check_assist(
             extract_variable,
             r#"
diff --git a/crates/ide_assists/src/handlers/fill_match_arms.rs b/crates/ide_assists/src/handlers/fill_match_arms.rs
index 7086e47d2..878b3a3fa 100644
--- a/crates/ide_assists/src/handlers/fill_match_arms.rs
+++ b/crates/ide_assists/src/handlers/fill_match_arms.rs
@@ -5,7 +5,6 @@ use ide_db::helpers::{mod_path_to_ast, FamousDefs};
 use ide_db::RootDatabase;
 use itertools::Itertools;
 use syntax::ast::{self, make, AstNode, MatchArm, NameOwner, Pat};
-use test_utils::mark;
 
 use crate::{
     utils::{does_pat_match_variant, render_snippet, Cursor},
@@ -62,7 +61,7 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
             .collect::<Vec<_>>();
         if Some(enum_def) == FamousDefs(&ctx.sema, Some(module.krate())).core_option_Option() {
             // Match `Some` variant first.
-            mark::hit!(option_order);
+            cov_mark::hit!(option_order);
             variants.reverse()
         }
         variants
@@ -195,7 +194,6 @@ fn build_pat(db: &RootDatabase, module: hir::Module, var: hir::Variant) -> Optio
 #[cfg(test)]
 mod tests {
     use ide_db::helpers::FamousDefs;
-    use test_utils::mark;
 
     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
 
@@ -730,7 +728,7 @@ fn main() {
 
     #[test]
     fn option_order() {
-        mark::check!(option_order);
+        cov_mark::check!(option_order);
         let before = r#"
 fn foo(opt: Option<i32>) {
     match opt$0 {
diff --git a/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs b/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
index 6a2ab9596..588ee1350 100644
--- a/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/generate_default_from_enum_variant.rs
@@ -1,7 +1,6 @@
 use ide_db::helpers::FamousDefs;
 use ide_db::RootDatabase;
 use syntax::ast::{self, AstNode, NameOwner};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -38,12 +37,12 @@ pub(crate) fn generate_default_from_enum_variant(
     let variant_name = variant.name()?;
     let enum_name = variant.parent_enum().name()?;
     if !matches!(variant.kind(), ast::StructKind::Unit) {
-        mark::hit!(test_gen_default_on_non_unit_variant_not_implemented);
+        cov_mark::hit!(test_gen_default_on_non_unit_variant_not_implemented);
         return None;
     }
 
     if existing_default_impl(&ctx.sema, &variant).is_some() {
-        mark::hit!(test_gen_default_impl_already_exists);
+        cov_mark::hit!(test_gen_default_impl_already_exists);
         return None;
     }
 
@@ -89,8 +88,6 @@ fn existing_default_impl(
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
@@ -127,7 +124,7 @@ impl Default for Variant {
 
     #[test]
     fn test_generate_default_already_implemented() {
-        mark::check!(test_gen_default_impl_already_exists);
+        cov_mark::check!(test_gen_default_impl_already_exists);
         check_not_applicable(
             r#"
 enum Variant {
@@ -146,7 +143,7 @@ impl Default for Variant {
 
     #[test]
     fn test_add_from_impl_no_element() {
-        mark::check!(test_gen_default_on_non_unit_variant_not_implemented);
+        cov_mark::check!(test_gen_default_on_non_unit_variant_not_implemented);
         check_not_applicable(
             r#"
 enum Variant {
diff --git a/crates/ide_assists/src/handlers/generate_default_from_new.rs b/crates/ide_assists/src/handlers/generate_default_from_new.rs
index fa1254579..81c54ba3e 100644
--- a/crates/ide_assists/src/handlers/generate_default_from_new.rs
+++ b/crates/ide_assists/src/handlers/generate_default_from_new.rs
@@ -7,7 +7,6 @@ use syntax::{
     ast::{self, Impl, NameOwner},
     AstNode,
 };
-use test_utils::mark;
 
 // Assist: generate_default_from_new
 //
@@ -43,19 +42,19 @@ pub(crate) fn generate_default_from_new(acc: &mut Assists, ctx: &AssistContext)
     let fn_name = fn_node.name()?;
 
     if fn_name.text() != "new" {
-        mark::hit!(other_function_than_new);
+        cov_mark::hit!(other_function_than_new);
         return None;
     }
 
     if fn_node.param_list()?.params().next().is_some() {
-        mark::hit!(new_function_with_parameters);
+        cov_mark::hit!(new_function_with_parameters);
         return None;
     }
 
     let impl_ = fn_node.syntax().ancestors().into_iter().find_map(ast::Impl::cast)?;
     if is_default_implemented(ctx, &impl_) {
-        mark::hit!(default_block_is_already_present);
-        mark::hit!(struct_in_module_with_default);
+        cov_mark::hit!(default_block_is_already_present);
+        cov_mark::hit!(struct_in_module_with_default);
         return None;
     }
 
@@ -178,7 +177,7 @@ impl Default for Test {
 
     #[test]
     fn new_function_with_parameters() {
-        mark::check!(new_function_with_parameters);
+        cov_mark::check!(new_function_with_parameters);
         check_not_applicable(
             r#"
 struct Example { _inner: () }
@@ -194,7 +193,7 @@ impl Example {
 
     #[test]
     fn other_function_than_new() {
-        mark::check!(other_function_than_new);
+        cov_mark::check!(other_function_than_new);
         check_not_applicable(
             r#"
 struct Example { _inner: () }
@@ -211,7 +210,7 @@ impl Example {
 
     #[test]
     fn default_block_is_already_present() {
-        mark::check!(default_block_is_already_present);
+        cov_mark::check!(default_block_is_already_present);
         check_not_applicable(
             r#"
 struct Example { _inner: () }
@@ -340,7 +339,7 @@ impl Default for Example {
 
     #[test]
     fn struct_in_module_with_default() {
-        mark::check!(struct_in_module_with_default);
+        cov_mark::check!(struct_in_module_with_default);
         check_not_applicable(
             r#"
 mod test {
diff --git a/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs b/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
index d9388a737..c13c6eebe 100644
--- a/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
+++ b/crates/ide_assists/src/handlers/generate_from_impl_for_enum.rs
@@ -1,7 +1,6 @@
 use ide_db::helpers::FamousDefs;
 use ide_db::RootDatabase;
 use syntax::ast::{self, AstNode, NameOwner};
-use test_utils::mark;
 
 use crate::{utils::generate_trait_impl_text, AssistContext, AssistId, AssistKind, Assists};
 
@@ -44,7 +43,7 @@ pub(crate) fn generate_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext
     };
 
     if existing_from_impl(&ctx.sema, &variant).is_some() {
-        mark::hit!(test_add_from_impl_already_exists);
+        cov_mark::hit!(test_add_from_impl_already_exists);
         return None;
     }
 
@@ -103,8 +102,6 @@ fn existing_from_impl(
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
@@ -172,7 +169,7 @@ impl From<u32> for A {
 
     #[test]
     fn test_add_from_impl_already_exists() {
-        mark::check!(test_add_from_impl_already_exists);
+        cov_mark::check!(test_add_from_impl_already_exists);
         check_not_applicable(
             r#"
 enum A { $0One(u32), }
diff --git a/crates/ide_assists/src/handlers/generate_function.rs b/crates/ide_assists/src/handlers/generate_function.rs
index 3870b7e75..6f95b1a07 100644
--- a/crates/ide_assists/src/handlers/generate_function.rs
+++ b/crates/ide_assists/src/handlers/generate_function.rs
@@ -83,17 +83,18 @@ struct FunctionTemplate {
     leading_ws: String,
     fn_def: ast::Fn,
     ret_type: ast::RetType,
+    should_render_snippet: bool,
     trailing_ws: String,
     file: FileId,
 }
 
 impl FunctionTemplate {
     fn to_string(&self, cap: Option<SnippetCap>) -> String {
-        let f = match cap {
-            Some(cap) => {
+        let f = match (cap, self.should_render_snippet) {
+            (Some(cap), true) => {
                 render_snippet(cap, self.fn_def.syntax(), Cursor::Replace(self.ret_type.syntax()))
             }
-            None => self.fn_def.to_string(),
+            _ => self.fn_def.to_string(),
         };
         format!("{}{}{}", self.leading_ws, f, self.trailing_ws)
     }
@@ -104,6 +105,8 @@ struct FunctionBuilder {
     fn_name: ast::Name,
     type_params: Option<ast::GenericParamList>,
     params: ast::ParamList,
+    ret_type: ast::RetType,
+    should_render_snippet: bool,
     file: FileId,
     needs_pub: bool,
 }
@@ -132,7 +135,43 @@ impl FunctionBuilder {
         let fn_name = fn_name(&path)?;
         let (type_params, params) = fn_args(ctx, target_module, &call)?;
 
-        Some(Self { target, fn_name, type_params, params, file, needs_pub })
+        // should_render_snippet intends to express a rough level of confidence about
+        // the correctness of the return type.
+        //
+        // If we are able to infer some return type, and that return type is not unit, we
+        // don't want to render the snippet. The assumption here is in this situation the
+        // return type is just as likely to be correct as any other part of the generated
+        // function.
+        //
+        // In the case where the return type is inferred as unit it is likely that the
+        // user does in fact intend for this generated function to return some non unit
+        // type, but that the current state of their code doesn't allow that return type
+        // to be accurately inferred.
+        let (ret_ty, should_render_snippet) = {
+            match ctx.sema.type_of_expr(&ast::Expr::CallExpr(call.clone())) {
+                Some(ty) if ty.is_unknown() || ty.is_unit() => (make::ty_unit(), true),
+                Some(ty) => {
+                    let rendered = ty.display_source_code(ctx.db(), target_module.into());
+                    match rendered {
+                        Ok(rendered) => (make::ty(&rendered), false),
+                        Err(_) => (make::ty_unit(), true),
+                    }
+                }
+                None => (make::ty_unit(), true),
+            }
+        };
+        let ret_type = make::ret_type(ret_ty);
+
+        Some(Self {
+            target,
+            fn_name,
+            type_params,
+            params,
+            ret_type,
+            should_render_snippet,
+            file,
+            needs_pub,
+        })
     }
 
     fn render(self) -> FunctionTemplate {
@@ -145,7 +184,7 @@ impl FunctionBuilder {
             self.type_params,
             self.params,
             fn_body,
-            Some(make::ret_type(make::ty_unit())),
+            Some(self.ret_type),
         );
         let leading_ws;
         let trailing_ws;
@@ -171,6 +210,7 @@ impl FunctionBuilder {
             insert_offset,
             leading_ws,
             ret_type: fn_def.ret_type().unwrap(),
+            should_render_snippet: self.should_render_snippet,
             fn_def,
             trailing_ws,
             file: self.file,
@@ -546,7 +586,7 @@ impl Baz {
     }
 }
 
-fn bar(baz: Baz) ${0:-> ()} {
+fn bar(baz: Baz) -> Baz {
     todo!()
 }
 ",
@@ -1060,6 +1100,27 @@ pub(crate) fn bar() ${0:-> ()} {
     }
 
     #[test]
+    fn add_function_with_return_type() {
+        check_assist(
+            generate_function,
+            r"
+fn main() {
+    let x: u32 = foo$0();
+}
+",
+            r"
+fn main() {
+    let x: u32 = foo();
+}
+
+fn foo() -> u32 {
+    todo!()
+}
+",
+        )
+    }
+
+    #[test]
     fn add_function_not_applicable_if_function_already_exists() {
         check_assist_not_applicable(
             generate_function,
diff --git a/crates/ide_assists/src/handlers/infer_function_return_type.rs b/crates/ide_assists/src/handlers/infer_function_return_type.rs
index 5279af1f3..66113751c 100644
--- a/crates/ide_assists/src/handlers/infer_function_return_type.rs
+++ b/crates/ide_assists/src/handlers/infer_function_return_type.rs
@@ -1,6 +1,5 @@
 use hir::HirDisplay;
 use syntax::{ast, AstNode, TextRange, TextSize};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -42,7 +41,7 @@ pub(crate) fn infer_function_return_type(acc: &mut Assists, ctx: &AssistContext)
                 }
             }
             if let FnType::Closure { wrap_expr: true } = fn_type {
-                mark::hit!(wrap_closure_non_block_expr);
+                cov_mark::hit!(wrap_closure_non_block_expr);
                 // `|x| x` becomes `|x| -> T x` which is invalid, so wrap it in a block
                 builder.replace(tail_expr.syntax().text_range(), &format!("{{{}}}", tail_expr));
             }
@@ -61,13 +60,13 @@ fn ret_ty_to_action(ret_ty: Option<ast::RetType>, insert_pos: TextSize) -> Optio
     match ret_ty {
         Some(ret_ty) => match ret_ty.ty() {
             Some(ast::Type::InferType(_)) | None => {
-                mark::hit!(existing_infer_ret_type);
-                mark::hit!(existing_infer_ret_type_closure);
+                cov_mark::hit!(existing_infer_ret_type);
+                cov_mark::hit!(existing_infer_ret_type_closure);
                 Some(InsertOrReplace::Replace(ret_ty.syntax().text_range()))
             }
             _ => {
-                mark::hit!(existing_ret_type);
-                mark::hit!(existing_ret_type_closure);
+                cov_mark::hit!(existing_ret_type);
+                cov_mark::hit!(existing_ret_type_closure);
                 None
             }
         },
@@ -109,11 +108,11 @@ fn extract_tail(ctx: &AssistContext) -> Option<(FnType, ast::Expr, InsertOrRepla
         };
     let frange = ctx.frange.range;
     if return_type_range.contains_range(frange) {
-        mark::hit!(cursor_in_ret_position);
-        mark::hit!(cursor_in_ret_position_closure);
+        cov_mark::hit!(cursor_in_ret_position);
+        cov_mark::hit!(cursor_in_ret_position_closure);
     } else if tail_expr.syntax().text_range().contains_range(frange) {
-        mark::hit!(cursor_on_tail);
-        mark::hit!(cursor_on_tail_closure);
+        cov_mark::hit!(cursor_on_tail);
+        cov_mark::hit!(cursor_on_tail_closure);
     } else {
         return None;
     }
@@ -128,7 +127,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_specified_inferred() {
-        mark::check!(existing_infer_ret_type);
+        cov_mark::check!(existing_infer_ret_type);
         check_assist(
             infer_function_return_type,
             r#"fn foo() -> $0_ {
@@ -142,7 +141,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_specified_inferred_closure() {
-        mark::check!(existing_infer_ret_type_closure);
+        cov_mark::check!(existing_infer_ret_type_closure);
         check_assist(
             infer_function_return_type,
             r#"fn foo() {
@@ -156,7 +155,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_cursor_at_return_type_pos() {
-        mark::check!(cursor_in_ret_position);
+        cov_mark::check!(cursor_in_ret_position);
         check_assist(
             infer_function_return_type,
             r#"fn foo() $0{
@@ -170,7 +169,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_cursor_at_return_type_pos_closure() {
-        mark::check!(cursor_in_ret_position_closure);
+        cov_mark::check!(cursor_in_ret_position_closure);
         check_assist(
             infer_function_return_type,
             r#"fn foo() {
@@ -184,7 +183,7 @@ mod tests {
 
     #[test]
     fn infer_return_type() {
-        mark::check!(cursor_on_tail);
+        cov_mark::check!(cursor_on_tail);
         check_assist(
             infer_function_return_type,
             r#"fn foo() {
@@ -219,7 +218,7 @@ mod tests {
 
     #[test]
     fn not_applicable_ret_type_specified() {
-        mark::check!(existing_ret_type);
+        cov_mark::check!(existing_ret_type);
         check_assist_not_applicable(
             infer_function_return_type,
             r#"fn foo() -> i32 {
@@ -251,7 +250,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_closure_block() {
-        mark::check!(cursor_on_tail_closure);
+        cov_mark::check!(cursor_on_tail_closure);
         check_assist(
             infer_function_return_type,
             r#"fn foo() {
@@ -282,7 +281,7 @@ mod tests {
 
     #[test]
     fn infer_return_type_closure_wrap() {
-        mark::check!(wrap_closure_non_block_expr);
+        cov_mark::check!(wrap_closure_non_block_expr);
         check_assist(
             infer_function_return_type,
             r#"fn foo() {
@@ -321,7 +320,7 @@ mod tests {
 
     #[test]
     fn not_applicable_ret_type_specified_closure() {
-        mark::check!(existing_ret_type_closure);
+        cov_mark::check!(existing_ret_type_closure);
         check_assist_not_applicable(
             infer_function_return_type,
             r#"fn foo() {
diff --git a/crates/ide_assists/src/handlers/inline_function.rs b/crates/ide_assists/src/handlers/inline_function.rs
index 6ec99b09b..8e56029cb 100644
--- a/crates/ide_assists/src/handlers/inline_function.rs
+++ b/crates/ide_assists/src/handlers/inline_function.rs
@@ -4,7 +4,6 @@ use syntax::{
     ast::{self, edit::AstNodeEdit, ArgListOwner},
     AstNode,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -49,7 +48,7 @@ pub(crate) fn inline_function(acc: &mut Assists, ctx: &AssistContext) -> Option<
     if arguments.len() != parameters.len() {
         // Can't inline the function because they've passed the wrong number of
         // arguments to this function
-        mark::hit!(inline_function_incorrect_number_of_arguments);
+        cov_mark::hit!(inline_function_incorrect_number_of_arguments);
         return None;
     }
 
@@ -155,7 +154,7 @@ fn main() { Foo.bar$0(); }
 
     #[test]
     fn not_applicable_when_incorrect_number_of_parameters_are_provided() {
-        mark::check!(inline_function_incorrect_number_of_arguments);
+        cov_mark::check!(inline_function_incorrect_number_of_arguments);
         check_assist_not_applicable(
             inline_function,
             r#"
diff --git a/crates/ide_assists/src/handlers/inline_local_variable.rs b/crates/ide_assists/src/handlers/inline_local_variable.rs
index da5522670..ea1466dc8 100644
--- a/crates/ide_assists/src/handlers/inline_local_variable.rs
+++ b/crates/ide_assists/src/handlers/inline_local_variable.rs
@@ -4,7 +4,6 @@ use syntax::{
     ast::{self, AstNode, AstToken},
     TextRange,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -34,11 +33,11 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
         _ => return None,
     };
     if bind_pat.mut_token().is_some() {
-        mark::hit!(test_not_inline_mut_variable);
+        cov_mark::hit!(test_not_inline_mut_variable);
         return None;
     }
     if !bind_pat.syntax().text_range().contains_inclusive(ctx.offset()) {
-        mark::hit!(not_applicable_outside_of_bind_pat);
+        cov_mark::hit!(not_applicable_outside_of_bind_pat);
         return None;
     }
     let initializer_expr = let_stmt.initializer()?;
@@ -47,7 +46,7 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
     let def = Definition::Local(def);
     let usages = def.usages(&ctx.sema).all();
     if usages.is_empty() {
-        mark::hit!(test_not_applicable_if_variable_unused);
+        cov_mark::hit!(test_not_applicable_if_variable_unused);
         return None;
     };
 
@@ -130,7 +129,7 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
                         Some(name_ref)
                             if ast::RecordExprField::for_field_name(name_ref).is_some() =>
                         {
-                            mark::hit!(inline_field_shorthand);
+                            cov_mark::hit!(inline_field_shorthand);
                             builder.insert(reference.range.end(), format!(": {}", replacement));
                         }
                         _ => builder.replace(reference.range, replacement),
@@ -143,8 +142,6 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
@@ -351,7 +348,7 @@ fn foo() {
 
     #[test]
     fn test_not_inline_mut_variable() {
-        mark::check!(test_not_inline_mut_variable);
+        cov_mark::check!(test_not_inline_mut_variable);
         check_assist_not_applicable(
             inline_local_variable,
             r"
@@ -684,7 +681,7 @@ fn foo() {
 
     #[test]
     fn inline_field_shorthand() {
-        mark::check!(inline_field_shorthand);
+        cov_mark::check!(inline_field_shorthand);
         check_assist(
             inline_local_variable,
             r"
@@ -705,7 +702,7 @@ fn main() {
 
     #[test]
     fn test_not_applicable_if_variable_unused() {
-        mark::check!(test_not_applicable_if_variable_unused);
+        cov_mark::check!(test_not_applicable_if_variable_unused);
         check_assist_not_applicable(
             inline_local_variable,
             r"
@@ -718,7 +715,7 @@ fn foo() {
 
     #[test]
     fn not_applicable_outside_of_bind_pat() {
-        mark::check!(not_applicable_outside_of_bind_pat);
+        cov_mark::check!(not_applicable_outside_of_bind_pat);
         check_assist_not_applicable(
             inline_local_variable,
             r"
diff --git a/crates/ide_assists/src/handlers/move_module_to_file.rs b/crates/ide_assists/src/handlers/move_module_to_file.rs
index 91c395c1b..6e685b4b2 100644
--- a/crates/ide_assists/src/handlers/move_module_to_file.rs
+++ b/crates/ide_assists/src/handlers/move_module_to_file.rs
@@ -5,7 +5,6 @@ use syntax::{
     ast::{self, edit::AstNodeEdit, NameOwner},
     AstNode, TextRange,
 };
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -28,7 +27,7 @@ pub(crate) fn move_module_to_file(acc: &mut Assists, ctx: &AssistContext) -> Opt
 
     let l_curly_offset = module_items.syntax().text_range().start();
     if l_curly_offset <= ctx.offset() {
-        mark::hit!(available_before_curly);
+        cov_mark::hit!(available_before_curly);
         return None;
     }
     let target = TextRange::new(module_ast.syntax().text_range().start(), l_curly_offset);
@@ -182,7 +181,7 @@ pub(crate) mod tests;
 
     #[test]
     fn available_before_curly() {
-        mark::check!(available_before_curly);
+        cov_mark::check!(available_before_curly);
         check_assist_not_applicable(move_module_to_file, r#"mod m { $0 }"#);
     }
 }
diff --git a/crates/ide_assists/src/handlers/pull_assignment_up.rs b/crates/ide_assists/src/handlers/pull_assignment_up.rs
index 377ed4f2f..04bae4e58 100644
--- a/crates/ide_assists/src/handlers/pull_assignment_up.rs
+++ b/crates/ide_assists/src/handlers/pull_assignment_up.rs
@@ -2,7 +2,6 @@ use syntax::{
     ast::{self, edit::AstNodeEdit, make},
     AstNode,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -104,7 +103,7 @@ fn exprify_if(
             ast::ElseBranch::Block(exprify_block(block, sema, name)?)
         }
         ast::ElseBranch::IfExpr(expr) => {
-            mark::hit!(test_pull_assignment_up_chained_if);
+            cov_mark::hit!(test_pull_assignment_up_chained_if);
             ast::ElseBranch::IfExpr(ast::IfExpr::cast(
                 exprify_if(&expr, sema, name)?.syntax().to_owned(),
             )?)
@@ -144,7 +143,7 @@ fn is_equivalent(
 ) -> bool {
     match (expr0, expr1) {
         (ast::Expr::FieldExpr(field_expr0), ast::Expr::FieldExpr(field_expr1)) => {
-            mark::hit!(test_pull_assignment_up_field_assignment);
+            cov_mark::hit!(test_pull_assignment_up_field_assignment);
             sema.resolve_field(field_expr0) == sema.resolve_field(field_expr1)
         }
         (ast::Expr::PathExpr(path0), ast::Expr::PathExpr(path1)) => {
@@ -160,7 +159,7 @@ fn is_equivalent(
             if prefix0.op_kind() == Some(ast::PrefixOp::Deref)
                 && prefix1.op_kind() == Some(ast::PrefixOp::Deref) =>
         {
-            mark::hit!(test_pull_assignment_up_deref);
+            cov_mark::hit!(test_pull_assignment_up_deref);
             if let (Some(prefix0), Some(prefix1)) = (prefix0.expr(), prefix1.expr()) {
                 is_equivalent(sema, &prefix0, &prefix1)
             } else {
@@ -263,7 +262,7 @@ fn foo() {
 
     #[test]
     fn test_pull_assignment_up_chained_if() {
-        mark::check!(test_pull_assignment_up_chained_if);
+        cov_mark::check!(test_pull_assignment_up_chained_if);
         check_assist(
             pull_assignment_up,
             r#"
@@ -379,7 +378,7 @@ fn foo() {
 
     #[test]
     fn test_pull_assignment_up_field_assignment() {
-        mark::check!(test_pull_assignment_up_field_assignment);
+        cov_mark::check!(test_pull_assignment_up_field_assignment);
         check_assist(
             pull_assignment_up,
             r#"
@@ -411,7 +410,7 @@ fn foo() {
 
     #[test]
     fn test_pull_assignment_up_deref() {
-        mark::check!(test_pull_assignment_up_deref);
+        cov_mark::check!(test_pull_assignment_up_deref);
         check_assist(
             pull_assignment_up,
             r#"
diff --git a/crates/ide_assists/src/handlers/qualify_path.rs b/crates/ide_assists/src/handlers/qualify_path.rs
index b0b0d31b4..30b23da6c 100644
--- a/crates/ide_assists/src/handlers/qualify_path.rs
+++ b/crates/ide_assists/src/handlers/qualify_path.rs
@@ -1,14 +1,16 @@
 use std::iter;
 
-use hir::{AsAssocItem, AsName};
-use ide_db::helpers::{import_assets::ImportCandidate, mod_path_to_ast};
+use hir::AsAssocItem;
+use ide_db::helpers::{
+    import_assets::{ImportCandidate, LocatedImport},
+    mod_path_to_ast,
+};
 use ide_db::RootDatabase;
 use syntax::{
     ast,
     ast::{make, ArgListOwner},
     AstNode,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -47,32 +49,32 @@ pub(crate) fn qualify_path(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     let qualify_candidate = match candidate {
         ImportCandidate::Path(candidate) => {
             if candidate.qualifier.is_some() {
-                mark::hit!(qualify_path_qualifier_start);
+                cov_mark::hit!(qualify_path_qualifier_start);
                 let path = ast::Path::cast(syntax_under_caret)?;
                 let (prev_segment, segment) = (path.qualifier()?.segment()?, path.segment()?);
                 QualifyCandidate::QualifierStart(segment, prev_segment.generic_arg_list())
             } else {
-                mark::hit!(qualify_path_unqualified_name);
+                cov_mark::hit!(qualify_path_unqualified_name);
                 let path = ast::Path::cast(syntax_under_caret)?;
                 let generics = path.segment()?.generic_arg_list();
                 QualifyCandidate::UnqualifiedName(generics)
             }
         }
         ImportCandidate::TraitAssocItem(_) => {
-            mark::hit!(qualify_path_trait_assoc_item);
+            cov_mark::hit!(qualify_path_trait_assoc_item);
             let path = ast::Path::cast(syntax_under_caret)?;
             let (qualifier, segment) = (path.qualifier()?, path.segment()?);
             QualifyCandidate::TraitAssocItem(qualifier, segment)
         }
         ImportCandidate::TraitMethod(_) => {
-            mark::hit!(qualify_path_trait_method);
+            cov_mark::hit!(qualify_path_trait_method);
             let mcall_expr = ast::MethodCallExpr::cast(syntax_under_caret)?;
             QualifyCandidate::TraitMethod(ctx.sema.db, mcall_expr)
         }
     };
 
     let group_label = group_label(candidate);
-    for (import, item) in proposed_imports {
+    for import in proposed_imports {
         acc.add_group(
             &group_label,
             AssistId("qualify_path", AssistKind::QuickFix),
@@ -81,8 +83,8 @@ pub(crate) fn qualify_path(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
             |builder| {
                 qualify_candidate.qualify(
                     |replace_with: String| builder.replace(range, replace_with),
-                    import,
-                    item,
+                    &import.import_path,
+                    import.item_to_import,
                 )
             },
         );
@@ -98,8 +100,13 @@ enum QualifyCandidate<'db> {
 }
 
 impl QualifyCandidate<'_> {
-    fn qualify(&self, mut replacer: impl FnMut(String), import: hir::ModPath, item: hir::ItemInNs) {
-        let import = mod_path_to_ast(&import);
+    fn qualify(
+        &self,
+        mut replacer: impl FnMut(String),
+        import: &hir::ModPath,
+        item: hir::ItemInNs,
+    ) {
+        let import = mod_path_to_ast(import);
         match self {
             QualifyCandidate::QualifierStart(segment, generics) => {
                 let generics = generics.as_ref().map_or_else(String::new, ToString::to_string);
@@ -160,7 +167,9 @@ fn find_trait_method(
 ) -> Option<hir::Function> {
     if let Some(hir::AssocItem::Function(method)) =
         trait_.items(db).into_iter().find(|item: &hir::AssocItem| {
-            item.name(db).map(|name| name == trait_method_name.as_name()).unwrap_or(false)
+            item.name(db)
+                .map(|name| name.to_string() == trait_method_name.to_string())
+                .unwrap_or(false)
         })
     {
         Some(method)
@@ -182,23 +191,25 @@ fn item_as_trait(db: &RootDatabase, item: hir::ItemInNs) -> Option<hir::Trait> {
 fn group_label(candidate: &ImportCandidate) -> GroupLabel {
     let name = match candidate {
         ImportCandidate::Path(it) => &it.name,
-        ImportCandidate::TraitAssocItem(it) | ImportCandidate::TraitMethod(it) => &it.name,
+        ImportCandidate::TraitAssocItem(it) | ImportCandidate::TraitMethod(it) => {
+            &it.assoc_item_name
+        }
     }
     .text();
     GroupLabel(format!("Qualify {}", name))
 }
 
-fn label(candidate: &ImportCandidate, import: &hir::ModPath) -> String {
+fn label(candidate: &ImportCandidate, import: &LocatedImport) -> String {
     match candidate {
         ImportCandidate::Path(candidate) => {
             if candidate.qualifier.is_some() {
-                format!("Qualify with `{}`", &import)
+                format!("Qualify with `{}`", import.import_path)
             } else {
-                format!("Qualify as `{}`", &import)
+                format!("Qualify as `{}`", import.import_path)
             }
         }
-        ImportCandidate::TraitAssocItem(_) => format!("Qualify `{}`", &import),
-        ImportCandidate::TraitMethod(_) => format!("Qualify with cast as `{}`", &import),
+        ImportCandidate::TraitAssocItem(_) => format!("Qualify `{}`", import.import_path),
+        ImportCandidate::TraitMethod(_) => format!("Qualify with cast as `{}`", import.import_path),
     }
 }
 
@@ -210,7 +221,7 @@ mod tests {
 
     #[test]
     fn applicable_when_found_an_import_partial() {
-        mark::check!(qualify_path_unqualified_name);
+        cov_mark::check!(qualify_path_unqualified_name);
         check_assist(
             qualify_path,
             r"
@@ -502,7 +513,7 @@ fn main() {
 
     #[test]
     fn associated_struct_const() {
-        mark::check!(qualify_path_qualifier_start);
+        cov_mark::check!(qualify_path_qualifier_start);
         check_assist(
             qualify_path,
             r"
@@ -603,7 +614,7 @@ fn main() {
 
     #[test]
     fn associated_trait_const() {
-        mark::check!(qualify_path_trait_assoc_item);
+        cov_mark::check!(qualify_path_trait_assoc_item);
         check_assist(
             qualify_path,
             r"
@@ -673,7 +684,7 @@ fn main() {
 
     #[test]
     fn trait_method() {
-        mark::check!(qualify_path_trait_method);
+        cov_mark::check!(qualify_path_trait_method);
         check_assist(
             qualify_path,
             r"
diff --git a/crates/ide_assists/src/handlers/raw_string.rs b/crates/ide_assists/src/handlers/raw_string.rs
index d95267607..d0f1613f3 100644
--- a/crates/ide_assists/src/handlers/raw_string.rs
+++ b/crates/ide_assists/src/handlers/raw_string.rs
@@ -1,7 +1,6 @@
 use std::borrow::Cow;
 
 use syntax::{ast, AstToken, TextRange, TextSize};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -149,7 +148,7 @@ pub(crate) fn remove_hash(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     let internal_text = &text[token.text_range_between_quotes()? - text_range.start()];
 
     if existing_hashes == required_hashes(internal_text) {
-        mark::hit!(cant_remove_required_hash);
+        cov_mark::hit!(cant_remove_required_hash);
         return None;
     }
 
@@ -182,8 +181,6 @@ fn test_required_hashes() {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
 
     use super::*;
@@ -396,7 +393,7 @@ string"###;
 
     #[test]
     fn cant_remove_required_hash() {
-        mark::check!(cant_remove_required_hash);
+        cov_mark::check!(cant_remove_required_hash);
         check_assist_not_applicable(
             remove_hash,
             r##"
diff --git a/crates/ide_assists/src/handlers/remove_unused_param.rs b/crates/ide_assists/src/handlers/remove_unused_param.rs
index c961680e2..2699d2861 100644
--- a/crates/ide_assists/src/handlers/remove_unused_param.rs
+++ b/crates/ide_assists/src/handlers/remove_unused_param.rs
@@ -4,7 +4,7 @@ use syntax::{
     ast::{self, ArgListOwner},
     AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange, T,
 };
-use test_utils::mark;
+
 use SyntaxKind::WHITESPACE;
 
 use crate::{
@@ -49,7 +49,7 @@ pub(crate) fn remove_unused_param(acc: &mut Assists, ctx: &AssistContext) -> Opt
         Definition::Local(local)
     };
     if param_def.usages(&ctx.sema).at_least_one() {
-        mark::hit!(keep_used);
+        cov_mark::hit!(keep_used);
         return None;
     }
     acc.add(
@@ -243,7 +243,7 @@ fn b2() { foo(9) }
 
     #[test]
     fn keep_used() {
-        mark::check!(keep_used);
+        cov_mark::check!(keep_used);
         check_assist_not_applicable(
             remove_unused_param,
             r#"
diff --git a/crates/ide_assists/src/handlers/reorder_fields.rs b/crates/ide_assists/src/handlers/reorder_fields.rs
index fba7d6ddb..794c89323 100644
--- a/crates/ide_assists/src/handlers/reorder_fields.rs
+++ b/crates/ide_assists/src/handlers/reorder_fields.rs
@@ -4,7 +4,6 @@ use rustc_hash::FxHashMap;
 use hir::{Adt, ModuleDef, PathResolution, Semantics, Struct};
 use ide_db::RootDatabase;
 use syntax::{algo, ast, match_ast, AstNode, SyntaxKind, SyntaxKind::*, SyntaxNode};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -39,7 +38,7 @@ fn reorder<R: AstNode>(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     });
 
     if sorted_fields == fields {
-        mark::hit!(reorder_sorted_fields);
+        cov_mark::hit!(reorder_sorted_fields);
         return None;
     }
 
@@ -109,15 +108,13 @@ fn compute_fields_ranks(path: &ast::Path, ctx: &AssistContext) -> Option<FxHashM
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
 
     #[test]
     fn reorder_sorted_fields() {
-        mark::check!(reorder_sorted_fields);
+        cov_mark::check!(reorder_sorted_fields);
         check_assist_not_applicable(
             reorder_fields,
             r#"
diff --git a/crates/ide_assists/src/handlers/reorder_impl.rs b/crates/ide_assists/src/handlers/reorder_impl.rs
index 309f291c8..edf4b0bfe 100644
--- a/crates/ide_assists/src/handlers/reorder_impl.rs
+++ b/crates/ide_assists/src/handlers/reorder_impl.rs
@@ -8,7 +8,6 @@ use syntax::{
     ast::{self, NameOwner},
     AstNode,
 };
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -71,7 +70,7 @@ pub(crate) fn reorder_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
 
     // Don't edit already sorted methods:
     if methods == sorted {
-        mark::hit!(not_applicable_if_sorted);
+        cov_mark::hit!(not_applicable_if_sorted);
         return None;
     }
 
@@ -121,15 +120,13 @@ fn get_methods(items: &ast::AssocItemList) -> Vec<ast::Fn> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
 
     #[test]
     fn not_applicable_if_sorted() {
-        mark::check!(not_applicable_if_sorted);
+        cov_mark::check!(not_applicable_if_sorted);
         check_assist_not_applicable(
             reorder_impl,
             r#"
diff --git a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
index c69bc5cac..88fe2fe90 100644
--- a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
+++ b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
@@ -1,5 +1,6 @@
+use hir::ModuleDef;
 use ide_db::helpers::mod_path_to_ast;
-use ide_db::imports_locator;
+use ide_db::items_locator;
 use itertools::Itertools;
 use syntax::{
     ast::{self, make, AstNode, NameOwner},
@@ -64,22 +65,20 @@ pub(crate) fn replace_derive_with_manual_impl(
     let current_module = ctx.sema.scope(annotated_name.syntax()).module()?;
     let current_crate = current_module.krate();
 
-    let found_traits = imports_locator::find_exact_imports(
-        &ctx.sema,
-        current_crate,
-        trait_token.text().to_string(),
-    )
-    .filter_map(|candidate: either::Either<hir::ModuleDef, hir::MacroDef>| match candidate {
-        either::Either::Left(hir::ModuleDef::Trait(trait_)) => Some(trait_),
-        _ => None,
-    })
-    .flat_map(|trait_| {
-        current_module
-            .find_use_path(ctx.sema.db, hir::ModuleDef::Trait(trait_))
-            .as_ref()
-            .map(mod_path_to_ast)
-            .zip(Some(trait_))
-    });
+    let found_traits =
+        items_locator::with_exact_name(&ctx.sema, current_crate, trait_token.text().to_string())
+            .into_iter()
+            .filter_map(|item| match ModuleDef::from(item.as_module_def_id()?) {
+                ModuleDef::Trait(trait_) => Some(trait_),
+                _ => None,
+            })
+            .flat_map(|trait_| {
+                current_module
+                    .find_use_path(ctx.sema.db, hir::ModuleDef::Trait(trait_))
+                    .as_ref()
+                    .map(mod_path_to_ast)
+                    .zip(Some(trait_))
+            });
 
     let mut no_traits_found = true;
     for (trait_path, trait_) in found_traits.inspect(|_| no_traits_found = false) {
diff --git a/crates/ide_assists/src/handlers/replace_for_loop_with_for_each.rs b/crates/ide_assists/src/handlers/replace_for_loop_with_for_each.rs
index 27da28bc0..50b05ab0b 100644
--- a/crates/ide_assists/src/handlers/replace_for_loop_with_for_each.rs
+++ b/crates/ide_assists/src/handlers/replace_for_loop_with_for_each.rs
@@ -3,7 +3,6 @@ use hir::known;
 use ide_db::helpers::FamousDefs;
 use stdx::format_to;
 use syntax::{ast, AstNode};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -34,7 +33,7 @@ pub(crate) fn replace_for_loop_with_for_each(acc: &mut Assists, ctx: &AssistCont
     let pat = for_loop.pat()?;
     let body = for_loop.loop_body()?;
     if body.syntax().text_range().start() < ctx.offset() {
-        mark::hit!(not_available_in_body);
+        cov_mark::hit!(not_available_in_body);
         return None;
     }
 
@@ -187,7 +186,7 @@ fn main() {
 
     #[test]
     fn not_available_in_body() {
-        mark::check!(not_available_in_body);
+        cov_mark::check!(not_available_in_body);
         check_assist_not_applicable(
             replace_for_loop_with_for_each,
             r"
diff --git a/crates/ide_assists/src/handlers/replace_qualified_name_with_use.rs b/crates/ide_assists/src/handlers/replace_qualified_name_with_use.rs
index f3bc6cf39..36d2e0331 100644
--- a/crates/ide_assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/ide_assists/src/handlers/replace_qualified_name_with_use.rs
@@ -1,6 +1,5 @@
 use ide_db::helpers::insert_use::{insert_use, ImportScope};
 use syntax::{algo::SyntaxRewriter, ast, match_ast, AstNode, SyntaxNode};
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -27,7 +26,7 @@ pub(crate) fn replace_qualified_name_with_use(
         return None;
     }
     if path.qualifier().is_none() {
-        mark::hit!(dont_import_trivial_paths);
+        cov_mark::hit!(dont_import_trivial_paths);
         return None;
     }
 
@@ -44,7 +43,7 @@ pub(crate) fn replace_qualified_name_with_use(
             let mut rewriter = SyntaxRewriter::default();
             shorten_paths(&mut rewriter, syntax.clone(), &path);
             if let Some(ref import_scope) = ImportScope::from(syntax.clone()) {
-                rewriter += insert_use(import_scope, path, ctx.config.insert_use.merge);
+                rewriter += insert_use(import_scope, path, ctx.config.insert_use);
                 builder.rewrite(rewriter);
             }
         },
@@ -458,7 +457,7 @@ impl Debug for Foo {
 
     #[test]
     fn dont_import_trivial_paths() {
-        mark::check!(dont_import_trivial_paths);
+        cov_mark::check!(dont_import_trivial_paths);
         check_assist_not_applicable(
             replace_qualified_name_with_use,
             r"
diff --git a/crates/ide_assists/src/handlers/unmerge_use.rs b/crates/ide_assists/src/handlers/unmerge_use.rs
index 3dbef8e51..616af7c2e 100644
--- a/crates/ide_assists/src/handlers/unmerge_use.rs
+++ b/crates/ide_assists/src/handlers/unmerge_use.rs
@@ -3,7 +3,6 @@ use syntax::{
     ast::{self, edit::AstNodeEdit, VisibilityOwner},
     AstNode, SyntaxKind,
 };
-use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
@@ -27,7 +26,7 @@ pub(crate) fn unmerge_use(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
 
     let tree_list = tree.syntax().parent().and_then(ast::UseTreeList::cast)?;
     if tree_list.use_trees().count() < 2 {
-        mark::hit!(skip_single_use_item);
+        cov_mark::hit!(skip_single_use_item);
         return None;
     }
 
@@ -89,7 +88,7 @@ mod tests {
 
     #[test]
     fn skip_single_use_item() {
-        mark::check!(skip_single_use_item);
+        cov_mark::check!(skip_single_use_item);
         check_assist_not_applicable(
             unmerge_use,
             r"
diff --git a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
index fec16fc49..e838630ea 100644
--- a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
+++ b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
@@ -4,7 +4,6 @@ use syntax::{
     ast::{self, make, BlockExpr, Expr, LoopBodyOwner},
     match_ast, AstNode, SyntaxNode,
 };
-use test_utils::mark;
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
 
@@ -39,7 +38,7 @@ pub(crate) fn wrap_return_type_in_result(acc: &mut Assists, ctx: &AssistContext)
     let first_part_ret_type = ret_type_str.splitn(2, '<').next();
     if let Some(ret_type_first_part) = first_part_ret_type {
         if ret_type_first_part.ends_with("Result") {
-            mark::hit!(wrap_return_type_in_result_simple_return_type_already_result);
+            cov_mark::hit!(wrap_return_type_in_result_simple_return_type_already_result);
             return None;
         }
     }
@@ -367,7 +366,7 @@ fn foo() -> std::result::Result<i32$0, String> {
 
     #[test]
     fn wrap_return_type_in_result_simple_return_type_already_result() {
-        mark::check!(wrap_return_type_in_result_simple_return_type_already_result);
+        cov_mark::check!(wrap_return_type_in_result_simple_return_type_already_result);
         check_assist_not_applicable(
             wrap_return_type_in_result,
             r#"
diff --git a/crates/ide_assists/src/lib.rs b/crates/ide_assists/src/lib.rs
index ea62d5f5d..f1aab74d4 100644
--- a/crates/ide_assists/src/lib.rs
+++ b/crates/ide_assists/src/lib.rs
@@ -116,6 +116,7 @@ mod handlers {
     mod change_visibility;
     mod convert_integer_literal;
     mod convert_comment_block;
+    mod convert_iter_for_each_to_for;
     mod early_return;
     mod expand_glob_import;
     mod extract_function;
@@ -181,6 +182,7 @@ mod handlers {
             change_visibility::change_visibility,
             convert_integer_literal::convert_integer_literal,
             convert_comment_block::convert_comment_block,
+            convert_iter_for_each_to_for::convert_iter_for_each_to_for,
             early_return::convert_to_guarded_return,
             expand_glob_import::expand_glob_import,
             extract_struct_from_enum_variant::extract_struct_from_enum_variant,
diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index b7f616760..a7a923beb 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -23,6 +23,7 @@ pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
     insert_use: InsertUseConfig {
         merge: Some(MergeBehavior::Full),
         prefix_kind: hir::PrefixKind::Plain,
+        group: true,
     },
 };
 
diff --git a/crates/ide_assists/src/tests/generated.rs b/crates/ide_assists/src/tests/generated.rs
index 304b5798f..3f77edd8d 100644
--- a/crates/ide_assists/src/tests/generated.rs
+++ b/crates/ide_assists/src/tests/generated.rs
@@ -206,6 +206,36 @@ const _: i32 = 0b1010;
 }
 
 #[test]
+fn doctest_convert_iter_for_each_to_for() {
+    check_doc_test(
+        "convert_iter_for_each_to_for",
+        r#####"
+//- /lib.rs crate:core
+pub mod iter { pub mod traits { pub mod iterator { pub trait Iterator {} } } }
+pub struct SomeIter;
+impl self::iter::traits::iterator::Iterator for SomeIter {}
+//- /lib.rs crate:main deps:core
+use core::SomeIter;
+fn main() {
+    let iter = SomeIter;
+    iter.for_each$0(|(x, y)| {
+        println!("x: {}, y: {}", x, y);
+    });
+}
+"#####,
+        r#####"
+use core::SomeIter;
+fn main() {
+    let iter = SomeIter;
+    for (x, y) in iter {
+        println!("x: {}, y: {}", x, y);
+    }
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_convert_to_guarded_return() {
     check_doc_test(
         "convert_to_guarded_return",
diff --git a/crates/ide_completion/Cargo.toml b/crates/ide_completion/Cargo.toml
index c09101ccb..585ecca50 100644
--- a/crates/ide_completion/Cargo.toml
+++ b/crates/ide_completion/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 itertools = "0.10.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
@@ -21,11 +22,11 @@ text_edit = { path = "../text_edit", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 # completions crate should depend only on the top-level `hir` package. if you need
 # something from some `hir_xxx` subpackage, reexport the API via `hir`.
 hir = { path = "../hir", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide_completion/src/completions/attribute.rs b/crates/ide_completion/src/completions/attribute.rs
index cb05e85fc..e846678b4 100644
--- a/crates/ide_completion/src/completions/attribute.rs
+++ b/crates/ide_completion/src/completions/attribute.rs
@@ -45,15 +45,15 @@ fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attr
             CompletionKind::Attribute,
             ctx.source_range(),
             attr_completion.label,
-        )
-        .kind(CompletionItemKind::Attribute);
+        );
+        item.kind(CompletionItemKind::Attribute);
 
         if let Some(lookup) = attr_completion.lookup {
-            item = item.lookup_by(lookup);
+            item.lookup_by(lookup);
         }
 
         if let Some((snippet, cap)) = attr_completion.snippet.zip(ctx.config.snippet_cap) {
-            item = item.insert_snippet(cap, snippet);
+            item.insert_snippet(cap, snippet);
         }
 
         if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
@@ -168,16 +168,20 @@ fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input:
             );
             let lookup = components.join(", ");
             let label = components.iter().rev().join(", ");
-            CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label)
-                .lookup_by(lookup)
-                .kind(CompletionItemKind::Attribute)
-                .add_to(acc)
+            let mut item =
+                CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label);
+            item.lookup_by(lookup).kind(CompletionItemKind::Attribute);
+            item.add_to(acc);
         }
 
         for custom_derive_name in get_derive_names_in_scope(ctx).difference(&existing_derives) {
-            CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), custom_derive_name)
-                .kind(CompletionItemKind::Attribute)
-                .add_to(acc)
+            let mut item = CompletionItem::new(
+                CompletionKind::Attribute,
+                ctx.source_range(),
+                custom_derive_name,
+            );
+            item.kind(CompletionItemKind::Attribute);
+            item.add_to(acc);
         }
     }
 }
@@ -193,14 +197,13 @@ fn complete_lint(
             .into_iter()
             .filter(|completion| !existing_lints.contains(completion.label))
         {
-            CompletionItem::new(
+            let mut item = CompletionItem::new(
                 CompletionKind::Attribute,
                 ctx.source_range(),
                 lint_completion.label,
-            )
-            .kind(CompletionItemKind::Attribute)
-            .detail(lint_completion.description)
-            .add_to(acc)
+            );
+            item.kind(CompletionItemKind::Attribute).detail(lint_completion.description);
+            item.add_to(acc)
         }
     }
 }
diff --git a/crates/ide_completion/src/completions/dot.rs b/crates/ide_completion/src/completions/dot.rs
index 084d7721d..5ee9a9f07 100644
--- a/crates/ide_completion/src/completions/dot.rs
+++ b/crates/ide_completion/src/completions/dot.rs
@@ -2,7 +2,6 @@
 
 use hir::{HasVisibility, Type};
 use rustc_hash::FxHashSet;
-use test_utils::mark;
 
 use crate::{context::CompletionContext, Completions};
 
@@ -19,7 +18,7 @@ pub(crate) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     };
 
     if ctx.is_call {
-        mark::hit!(test_no_struct_field_completion_for_method_call);
+        cov_mark::hit!(test_no_struct_field_completion_for_method_call);
     } else {
         complete_fields(acc, ctx, &receiver_ty);
     }
@@ -62,7 +61,6 @@ fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &T
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{test_utils::completion_list, CompletionKind};
 
@@ -122,7 +120,7 @@ impl A {
 
     #[test]
     fn test_no_struct_field_completion_for_method_call() {
-        mark::check!(test_no_struct_field_completion_for_method_call);
+        cov_mark::check!(test_no_struct_field_completion_for_method_call);
         check(
             r#"
 struct A { the_field: u32 }
diff --git a/crates/ide_completion/src/completions/flyimport.rs b/crates/ide_completion/src/completions/flyimport.rs
index da8375af9..391a11c91 100644
--- a/crates/ide_completion/src/completions/flyimport.rs
+++ b/crates/ide_completion/src/completions/flyimport.rs
@@ -21,6 +21,46 @@
 //! ```
 //!
 //! Also completes associated items, that require trait imports.
+//! If any unresolved and/or partially-qualified path predeces the input, it will be taken into account.
+//! Currently, only the imports with their import path ending with the whole qialifier will be proposed
+//! (no fuzzy matching for qualifier).
+//!
+//! ```
+//! mod foo {
+//!     pub mod bar {
+//!         pub struct Item;
+//!
+//!         impl Item {
+//!             pub const TEST_ASSOC: usize = 3;
+//!         }
+//!     }
+//! }
+//!
+//! fn main() {
+//!     bar::Item::TEST_A$0
+//! }
+//! ```
+//! ->
+//! ```
+//! use foo::bar;
+//!
+//! mod foo {
+//!     pub mod bar {
+//!         pub struct Item;
+//!
+//!         impl Item {
+//!             pub const TEST_ASSOC: usize = 3;
+//!         }
+//!     }
+//! }
+//!
+//! fn main() {
+//!     bar::Item::TEST_ASSOC
+//! }
+//! ```
+//!
+//! NOTE: currently, if an assoc item comes from a trait that's not currently imported and it also has an unresolved and/or partially-qualified path,
+//! no imports will be proposed.
 //!
 //! .Fuzzy search details
 //!
@@ -48,14 +88,13 @@
 //! Note that having this flag set to `true` does not guarantee that the feature is enabled: your client needs to have the corredponding
 //! capability enabled.
 
-use hir::{AsAssocItem, ModPath, ScopeDef};
+use hir::ModPath;
 use ide_db::helpers::{
     import_assets::{ImportAssets, ImportCandidate},
     insert_use::ImportScope,
 };
-use rustc_hash::FxHashSet;
+use itertools::Itertools;
 use syntax::{AstNode, SyntaxNode, T};
-use test_utils::mark;
 
 use crate::{
     context::CompletionContext,
@@ -93,50 +132,26 @@ pub(crate) fn import_on_the_fly(acc: &mut Completions, ctx: &CompletionContext)
         &ctx.sema,
     )?;
 
-    let scope_definitions = scope_definitions(ctx);
-    let mut all_mod_paths = import_assets
-        .search_for_imports(&ctx.sema, ctx.config.insert_use.prefix_kind)
-        .into_iter()
-        .map(|(mod_path, item_in_ns)| {
-            let scope_item = match item_in_ns {
-                hir::ItemInNs::Types(id) => ScopeDef::ModuleDef(id.into()),
-                hir::ItemInNs::Values(id) => ScopeDef::ModuleDef(id.into()),
-                hir::ItemInNs::Macros(id) => ScopeDef::MacroDef(id.into()),
-            };
-            (mod_path, scope_item)
-        })
-        .filter(|(_, proposed_def)| !scope_definitions.contains(proposed_def))
-        .collect::<Vec<_>>();
-    all_mod_paths.sort_by_cached_key(|(mod_path, _)| {
-        compute_fuzzy_completion_order_key(mod_path, &user_input_lowercased)
-    });
-
-    acc.add_all(all_mod_paths.into_iter().filter_map(|(import_path, definition)| {
-        let import_for_trait_assoc_item = match definition {
-            ScopeDef::ModuleDef(module_def) => module_def
-                .as_assoc_item(ctx.db)
-                .and_then(|assoc| assoc.containing_trait(ctx.db))
-                .is_some(),
-            _ => false,
-        };
-        let import_edit = ImportEdit {
-            import_path,
-            import_scope: import_scope.clone(),
-            import_for_trait_assoc_item,
-        };
-        render_resolution_with_import(RenderContext::new(ctx), import_edit, &definition)
-    }));
+    acc.add_all(
+        import_assets
+            .search_for_imports(&ctx.sema, ctx.config.insert_use.prefix_kind)
+            .into_iter()
+            .sorted_by_key(|located_import| {
+                compute_fuzzy_completion_order_key(
+                    &located_import.import_path,
+                    &user_input_lowercased,
+                )
+            })
+            .filter_map(|import| {
+                render_resolution_with_import(
+                    RenderContext::new(ctx),
+                    ImportEdit { import, scope: import_scope.clone() },
+                )
+            }),
+    );
     Some(())
 }
 
-fn scope_definitions(ctx: &CompletionContext) -> FxHashSet<ScopeDef> {
-    let mut scope_definitions = FxHashSet::default();
-    ctx.scope.process_all_names(&mut |_, scope_def| {
-        scope_definitions.insert(scope_def);
-    });
-    scope_definitions
-}
-
 pub(crate) fn position_for_import<'a>(
     ctx: &'a CompletionContext,
     import_candidate: Option<&ImportCandidate>,
@@ -161,23 +176,30 @@ fn import_assets(ctx: &CompletionContext, fuzzy_name: String) -> Option<ImportAs
             current_module,
             ctx.sema.type_of_expr(dot_receiver)?,
             fuzzy_name,
+            dot_receiver.syntax().clone(),
         )
     } else {
         let fuzzy_name_length = fuzzy_name.len();
+        let approximate_node = match current_module.definition_source(ctx.db).value {
+            hir::ModuleSource::SourceFile(s) => s.syntax().clone(),
+            hir::ModuleSource::Module(m) => m.syntax().clone(),
+            hir::ModuleSource::BlockExpr(b) => b.syntax().clone(),
+        };
         let assets_for_path = ImportAssets::for_fuzzy_path(
             current_module,
             ctx.path_qual.clone(),
             fuzzy_name,
             &ctx.sema,
-        );
+            approximate_node,
+        )?;
 
-        if matches!(assets_for_path.as_ref()?.import_candidate(), ImportCandidate::Path(_))
+        if matches!(assets_for_path.import_candidate(), ImportCandidate::Path(_))
             && fuzzy_name_length < 2
         {
-            mark::hit!(ignore_short_input_for_path);
+            cov_mark::hit!(ignore_short_input_for_path);
             None
         } else {
-            assets_for_path
+            Some(assets_for_path)
         }
     }
 }
@@ -186,12 +208,12 @@ fn compute_fuzzy_completion_order_key(
     proposed_mod_path: &ModPath,
     user_input_lowercased: &str,
 ) -> usize {
-    mark::hit!(certain_fuzzy_order_test);
-    let proposed_import_name = match proposed_mod_path.segments().last() {
+    cov_mark::hit!(certain_fuzzy_order_test);
+    let import_name = match proposed_mod_path.segments().last() {
         Some(name) => name.to_string().to_lowercase(),
         None => return usize::MAX,
     };
-    match proposed_import_name.match_indices(user_input_lowercased).next() {
+    match import_name.match_indices(user_input_lowercased).next() {
         Some((first_matching_index, _)) => first_matching_index,
         None => usize::MAX,
     }
@@ -200,7 +222,6 @@ fn compute_fuzzy_completion_order_key(
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         item::CompletionKind,
@@ -295,7 +316,7 @@ fn main() {
 
     #[test]
     fn short_paths_are_ignored() {
-        mark::check!(ignore_short_input_for_path);
+        cov_mark::check!(ignore_short_input_for_path);
 
         check(
             r#"
@@ -319,7 +340,7 @@ fn main() {
 
     #[test]
     fn fuzzy_completions_come_in_specific_order() {
-        mark::check!(certain_fuzzy_order_test);
+        cov_mark::check!(certain_fuzzy_order_test);
         check(
             r#"
 //- /lib.rs crate:dep
@@ -775,4 +796,155 @@ fn main() {
 }"#,
         );
     }
+
+    #[test]
+    fn unresolved_qualifier() {
+        let fixture = r#"
+mod foo {
+    pub mod bar {
+        pub mod baz {
+            pub struct Item;
+        }
+    }
+}
+
+fn main() {
+    bar::baz::Ite$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        st foo::bar::baz::Item
+        "#]],
+        );
+
+        check_edit(
+            "Item",
+            fixture,
+            r#"
+        use foo::bar;
+
+        mod foo {
+            pub mod bar {
+                pub mod baz {
+                    pub struct Item;
+                }
+            }
+        }
+
+        fn main() {
+            bar::baz::Item
+        }"#,
+        );
+    }
+
+    #[test]
+    fn unresolved_assoc_item_container() {
+        let fixture = r#"
+mod foo {
+    pub struct Item;
+
+    impl Item {
+        pub const TEST_ASSOC: usize = 3;
+    }
+}
+
+fn main() {
+    Item::TEST_A$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        ct TEST_ASSOC (foo::Item)
+        "#]],
+        );
+
+        check_edit(
+            "TEST_ASSOC",
+            fixture,
+            r#"
+use foo::Item;
+
+mod foo {
+    pub struct Item;
+
+    impl Item {
+        pub const TEST_ASSOC: usize = 3;
+    }
+}
+
+fn main() {
+    Item::TEST_ASSOC
+}"#,
+        );
+    }
+
+    #[test]
+    fn unresolved_assoc_item_container_with_path() {
+        let fixture = r#"
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Item::TEST_A$0
+}"#;
+
+        check(
+            fixture,
+            expect![[r#"
+        ct TEST_ASSOC (foo::bar::Item)
+    "#]],
+        );
+
+        check_edit(
+            "TEST_ASSOC",
+            fixture,
+            r#"
+use foo::bar;
+
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Item::TEST_ASSOC
+}"#,
+        );
+    }
+
+    #[test]
+    fn fuzzy_unresolved_path() {
+        check(
+            r#"
+mod foo {
+    pub mod bar {
+        pub struct Item;
+
+        impl Item {
+            pub const TEST_ASSOC: usize = 3;
+        }
+    }
+}
+
+fn main() {
+    bar::Ass$0
+}"#,
+            expect![[]],
+        )
+    }
 }
diff --git a/crates/ide_completion/src/completions/fn_param.rs b/crates/ide_completion/src/completions/fn_param.rs
index 1bcc8727f..0243dce56 100644
--- a/crates/ide_completion/src/completions/fn_param.rs
+++ b/crates/ide_completion/src/completions/fn_param.rs
@@ -54,10 +54,9 @@ pub(crate) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
     }
 
     params.into_iter().for_each(|(label, lookup)| {
-        CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
-            .kind(CompletionItemKind::Binding)
-            .lookup_by(lookup)
-            .add_to(acc)
+        let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label);
+        item.kind(CompletionItemKind::Binding).lookup_by(lookup);
+        item.add_to(acc)
     });
 }
 
diff --git a/crates/ide_completion/src/completions/keyword.rs b/crates/ide_completion/src/completions/keyword.rs
index 03c6dd454..b635e0ca3 100644
--- a/crates/ide_completion/src/completions/keyword.rs
+++ b/crates/ide_completion/src/completions/keyword.rs
@@ -3,7 +3,6 @@
 use std::iter;
 
 use syntax::SyntaxKind;
-use test_utils::mark;
 
 use crate::{CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions};
 
@@ -13,21 +12,19 @@ pub(crate) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
 
     if ctx.use_item_syntax.is_some() {
         if ctx.path_qual.is_none() {
-            CompletionItem::new(CompletionKind::Keyword, source_range, "crate::")
-                .kind(CompletionItemKind::Keyword)
-                .insert_text("crate::")
-                .add_to(acc);
+            let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "crate::");
+            item.kind(CompletionItemKind::Keyword).insert_text("crate::");
+            item.add_to(acc);
         }
-        CompletionItem::new(CompletionKind::Keyword, source_range, "self")
-            .kind(CompletionItemKind::Keyword)
-            .add_to(acc);
+        let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "self");
+        item.kind(CompletionItemKind::Keyword);
+        item.add_to(acc);
         if iter::successors(ctx.path_qual.clone(), |p| p.qualifier())
             .all(|p| p.segment().and_then(|s| s.super_token()).is_some())
         {
-            CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
-                .kind(CompletionItemKind::Keyword)
-                .insert_text("super::")
-                .add_to(acc);
+            let mut item = CompletionItem::new(CompletionKind::Keyword, source_range, "super::");
+            item.kind(CompletionItemKind::Keyword).insert_text("super::");
+            item.add_to(acc);
         }
     }
 
@@ -35,11 +32,10 @@ pub(crate) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
     if let Some(receiver) = &ctx.dot_receiver {
         if let Some(ty) = ctx.sema.type_of_expr(receiver) {
             if ty.impls_future(ctx.db) {
-                CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
-                    .kind(CompletionItemKind::Keyword)
-                    .detail("expr.await")
-                    .insert_text("await")
-                    .add_to(acc);
+                let mut item =
+                    CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await");
+                item.kind(CompletionItemKind::Keyword).detail("expr.await").insert_text("await");
+                item.add_to(acc);
             }
         };
     }
@@ -47,11 +43,11 @@ pub(crate) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
 
 pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionContext) {
     if ctx.token.kind() == SyntaxKind::COMMENT {
-        mark::hit!(no_keyword_completion_in_comments);
+        cov_mark::hit!(no_keyword_completion_in_comments);
         return;
     }
     if ctx.record_lit_syntax.is_some() {
-        mark::hit!(no_keyword_completion_in_record_lit);
+        cov_mark::hit!(no_keyword_completion_in_record_lit);
         return;
     }
 
@@ -166,29 +162,31 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
 }
 
 fn add_keyword(ctx: &CompletionContext, acc: &mut Completions, kw: &str, snippet: &str) {
-    let builder = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw)
-        .kind(CompletionItemKind::Keyword);
-    let builder = match ctx.config.snippet_cap {
+    let mut item = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw);
+    item.kind(CompletionItemKind::Keyword);
+
+    match ctx.config.snippet_cap {
         Some(cap) => {
             let tmp;
             let snippet = if snippet.ends_with('}') && ctx.incomplete_let {
-                mark::hit!(let_semi);
+                cov_mark::hit!(let_semi);
                 tmp = format!("{};", snippet);
                 &tmp
             } else {
                 snippet
             };
-            builder.insert_snippet(cap, snippet)
+            item.insert_snippet(cap, snippet);
+        }
+        None => {
+            item.insert_text(if snippet.contains('$') { kw } else { snippet });
         }
-        None => builder.insert_text(if snippet.contains('$') { kw } else { snippet }),
     };
-    acc.add(builder.build());
+    item.add_to(acc);
 }
 
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list},
@@ -494,7 +492,7 @@ fn quux() -> i32 {
 
     #[test]
     fn no_keyword_completion_in_comments() {
-        mark::check!(no_keyword_completion_in_comments);
+        cov_mark::check!(no_keyword_completion_in_comments);
         check(
             r#"
 fn test() {
@@ -599,7 +597,7 @@ struct Foo {
 
     #[test]
     fn skip_struct_initializer() {
-        mark::check!(no_keyword_completion_in_record_lit);
+        cov_mark::check!(no_keyword_completion_in_record_lit);
         check(
             r#"
 struct Foo {
@@ -643,7 +641,7 @@ fn foo() {
 
     #[test]
     fn let_semi() {
-        mark::check!(let_semi);
+        cov_mark::check!(let_semi);
         check_edit(
             "match",
             r#"
diff --git a/crates/ide_completion/src/completions/mod_.rs b/crates/ide_completion/src/completions/mod_.rs
index 352fc7c77..4f9415736 100644
--- a/crates/ide_completion/src/completions/mod_.rs
+++ b/crates/ide_completion/src/completions/mod_.rs
@@ -80,9 +80,9 @@ pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Op
             if mod_under_caret.semicolon_token().is_none() {
                 label.push(';');
             }
-            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), &label)
-                .kind(SymbolKind::Module)
-                .add_to(acc)
+            let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), &label);
+            item.kind(SymbolKind::Module);
+            item.add_to(acc)
         });
 
     Some(())
diff --git a/crates/ide_completion/src/completions/postfix.rs b/crates/ide_completion/src/completions/postfix.rs
index 9c34ed0b6..ac69b720a 100644
--- a/crates/ide_completion/src/completions/postfix.rs
+++ b/crates/ide_completion/src/completions/postfix.rs
@@ -187,6 +187,16 @@ pub(crate) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         ctx,
         cap,
         &dot_receiver,
+        "err",
+        "Err(expr)",
+        &format!("Err({})", receiver_text),
+    )
+    .add_to(acc);
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
         "some",
         "Some(expr)",
         &format!("Some({})", receiver_text),
@@ -287,10 +297,9 @@ fn postfix_snippet(
         let delete_range = TextRange::new(receiver_range.start(), ctx.source_range().end());
         TextEdit::replace(delete_range, snippet.to_string())
     };
-    CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label)
-        .detail(detail)
-        .kind(CompletionItemKind::Snippet)
-        .snippet_edit(cap, edit)
+    let mut item = CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label);
+    item.detail(detail).kind(CompletionItemKind::Snippet).snippet_edit(cap, edit);
+    item
 }
 
 #[cfg(test)]
@@ -325,6 +334,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -357,6 +367,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -380,6 +391,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
@@ -408,6 +420,7 @@ fn main() {
                 sn match match expr {}
                 sn box   Box::new(expr)
                 sn ok    Ok(expr)
+                sn err   Err(expr)
                 sn some  Some(expr)
                 sn dbg   dbg!(expr)
                 sn dbgr  dbg!(&expr)
diff --git a/crates/ide_completion/src/completions/qualified_path.rs b/crates/ide_completion/src/completions/qualified_path.rs
index 72fb757b1..df74b739e 100644
--- a/crates/ide_completion/src/completions/qualified_path.rs
+++ b/crates/ide_completion/src/completions/qualified_path.rs
@@ -3,7 +3,6 @@
 use hir::{Adt, HasVisibility, PathResolution, ScopeDef};
 use rustc_hash::FxHashSet;
 use syntax::AstNode;
-use test_utils::mark;
 
 use crate::{CompletionContext, Completions};
 
@@ -39,7 +38,7 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
                         if let Some(name_ref) = ctx.name_ref_syntax.as_ref() {
                             if name_ref.syntax().text() == name.to_string().as_str() {
                                 // for `use self::foo$0`, don't suggest `foo` as a completion
-                                mark::hit!(dont_complete_current_use);
+                                cov_mark::hit!(dont_complete_current_use);
                                 continue;
                             }
                         }
@@ -155,7 +154,6 @@ pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list},
@@ -174,7 +172,7 @@ mod tests {
 
     #[test]
     fn dont_complete_current_use() {
-        mark::check!(dont_complete_current_use);
+        cov_mark::check!(dont_complete_current_use);
         check(r#"use self::foo$0;"#, expect![[""]]);
     }
 
diff --git a/crates/ide_completion/src/completions/record.rs b/crates/ide_completion/src/completions/record.rs
index 0a7927eb8..2f95b8687 100644
--- a/crates/ide_completion/src/completions/record.rs
+++ b/crates/ide_completion/src/completions/record.rs
@@ -22,16 +22,13 @@ pub(crate) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) ->
                 let completion_text = completion_text
                     .strip_prefix(ctx.token.to_string().as_str())
                     .unwrap_or(completion_text);
-                acc.add(
-                    CompletionItem::new(
-                        CompletionKind::Snippet,
-                        ctx.source_range(),
-                        "..Default::default()",
-                    )
-                    .insert_text(completion_text)
-                    .kind(SymbolKind::Field)
-                    .build(),
+                let mut item = CompletionItem::new(
+                    CompletionKind::Snippet,
+                    ctx.source_range(),
+                    "..Default::default()",
                 );
+                item.insert_text(completion_text).kind(SymbolKind::Field);
+                item.add_to(acc);
             }
 
             missing_fields
diff --git a/crates/ide_completion/src/completions/snippet.rs b/crates/ide_completion/src/completions/snippet.rs
index df17a15c5..7f7830976 100644
--- a/crates/ide_completion/src/completions/snippet.rs
+++ b/crates/ide_completion/src/completions/snippet.rs
@@ -8,9 +8,9 @@ use crate::{
 };
 
 fn snippet(ctx: &CompletionContext, cap: SnippetCap, label: &str, snippet: &str) -> Builder {
-    CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label)
-        .insert_snippet(cap, snippet)
-        .kind(CompletionItemKind::Snippet)
+    let mut item = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label);
+    item.insert_snippet(cap, snippet).kind(CompletionItemKind::Snippet);
+    item
 }
 
 pub(crate) fn complete_expr_snippet(acc: &mut Completions, ctx: &CompletionContext) {
@@ -35,7 +35,7 @@ pub(crate) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionConte
         None => return,
     };
 
-    snippet(
+    let mut item = snippet(
         ctx,
         cap,
         "tmod (Test module)",
@@ -49,11 +49,11 @@ mod tests {
         $0
     }
 }",
-    )
-    .lookup_by("tmod")
-    .add_to(acc);
+    );
+    item.lookup_by("tmod");
+    item.add_to(acc);
 
-    snippet(
+    let mut item = snippet(
         ctx,
         cap,
         "tfn (Test function)",
@@ -62,11 +62,12 @@ mod tests {
 fn ${1:feature}() {
     $0
 }",
-    )
-    .lookup_by("tfn")
-    .add_to(acc);
+    );
+    item.lookup_by("tfn");
+    item.add_to(acc);
 
-    snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}").add_to(acc);
+    let item = snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}");
+    item.add_to(acc);
 }
 
 #[cfg(test)]
diff --git a/crates/ide_completion/src/completions/trait_impl.rs b/crates/ide_completion/src/completions/trait_impl.rs
index b999540b8..5a7361f8e 100644
--- a/crates/ide_completion/src/completions/trait_impl.rs
+++ b/crates/ide_completion/src/completions/trait_impl.rs
@@ -145,9 +145,8 @@ fn add_function_impl(
         format!("fn {}(..)", fn_name)
     };
 
-    let builder = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
-        .lookup_by(fn_name)
-        .set_documentation(func.docs(ctx.db));
+    let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label);
+    item.lookup_by(fn_name).set_documentation(func.docs(ctx.db));
 
     let completion_kind = if func.self_param(ctx.db).is_some() {
         CompletionItemKind::Method
@@ -161,15 +160,15 @@ fn add_function_impl(
         match ctx.config.snippet_cap {
             Some(cap) => {
                 let snippet = format!("{} {{\n    $0\n}}", function_decl);
-                builder.snippet_edit(cap, TextEdit::replace(range, snippet))
+                item.snippet_edit(cap, TextEdit::replace(range, snippet));
             }
             None => {
                 let header = format!("{} {{", function_decl);
-                builder.text_edit(TextEdit::replace(range, header))
+                item.text_edit(TextEdit::replace(range, header));
             }
-        }
-        .kind(completion_kind)
-        .add_to(acc);
+        };
+        item.kind(completion_kind);
+        item.add_to(acc);
     }
 }
 
@@ -185,12 +184,12 @@ fn add_type_alias_impl(
 
     let range = TextRange::new(type_def_node.text_range().start(), ctx.source_range().end());
 
-    CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
-        .text_edit(TextEdit::replace(range, snippet))
+    let mut item = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone());
+    item.text_edit(TextEdit::replace(range, snippet))
         .lookup_by(alias_name)
         .kind(SymbolKind::TypeAlias)
-        .set_documentation(type_alias.docs(ctx.db))
-        .add_to(acc);
+        .set_documentation(type_alias.docs(ctx.db));
+    item.add_to(acc);
 }
 
 fn add_const_impl(
@@ -208,12 +207,13 @@ fn add_const_impl(
             let range =
                 TextRange::new(const_def_node.text_range().start(), ctx.source_range().end());
 
-            CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone())
-                .text_edit(TextEdit::replace(range, snippet))
+            let mut item =
+                CompletionItem::new(CompletionKind::Magic, ctx.source_range(), snippet.clone());
+            item.text_edit(TextEdit::replace(range, snippet))
                 .lookup_by(const_name)
                 .kind(SymbolKind::Const)
-                .set_documentation(const_.docs(ctx.db))
-                .add_to(acc);
+                .set_documentation(const_.docs(ctx.db));
+            item.add_to(acc);
         }
     }
 }
diff --git a/crates/ide_completion/src/completions/unqualified_path.rs b/crates/ide_completion/src/completions/unqualified_path.rs
index e9d0ff665..044dfd160 100644
--- a/crates/ide_completion/src/completions/unqualified_path.rs
+++ b/crates/ide_completion/src/completions/unqualified_path.rs
@@ -2,7 +2,6 @@
 
 use hir::ScopeDef;
 use syntax::AstNode;
-use test_utils::mark;
 
 use crate::{CompletionContext, Completions};
 
@@ -30,13 +29,13 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
 
     ctx.scope.process_all_names(&mut |name, res| {
         if let ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) = res {
-            mark::hit!(skip_lifetime_completion);
+            cov_mark::hit!(skip_lifetime_completion);
             return;
         }
         if ctx.use_item_syntax.is_some() {
             if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
                 if name_ref.syntax().text() == name.to_string().as_str() {
-                    mark::hit!(self_fulfilling_completion);
+                    cov_mark::hit!(self_fulfilling_completion);
                     return;
                 }
             }
@@ -48,7 +47,6 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, completion_list_with_config, TEST_CONFIG},
@@ -66,7 +64,7 @@ mod tests {
 
     #[test]
     fn self_fulfilling_completion() {
-        mark::check!(self_fulfilling_completion);
+        cov_mark::check!(self_fulfilling_completion);
         check(
             r#"
 use foo$0
@@ -185,7 +183,7 @@ fn quux() {
 
     #[test]
     fn completes_if_prefix_is_keyword() {
-        mark::check!(completes_if_prefix_is_keyword);
+        cov_mark::check!(completes_if_prefix_is_keyword);
         check_edit(
             "wherewolf",
             r#"
@@ -223,7 +221,7 @@ fn main() {
 
     #[test]
     fn does_not_complete_lifetimes() {
-        mark::check!(skip_lifetime_completion);
+        cov_mark::check!(skip_lifetime_completion);
         check(
             r#"fn quux<'a>() { $0 }"#,
             expect![[r#"
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 3db357855..17d9a3adf 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -7,7 +7,7 @@ use syntax::{
     algo::find_node_at_offset, ast, match_ast, AstNode, NodeOrToken, SyntaxKind::*, SyntaxNode,
     SyntaxToken, TextRange, TextSize,
 };
-use test_utils::mark;
+
 use text_edit::Indel;
 
 use crate::{
@@ -240,7 +240,7 @@ impl<'a> CompletionContext<'a> {
         // check kind of macro-expanded token, but use range of original token
         let kind = self.token.kind();
         if kind == IDENT || kind == UNDERSCORE || kind.is_keyword() {
-            mark::hit!(completes_if_prefix_is_keyword);
+            cov_mark::hit!(completes_if_prefix_is_keyword);
             self.original_token.text_range()
         } else {
             TextRange::empty(self.position.offset)
diff --git a/crates/ide_completion/src/item.rs b/crates/ide_completion/src/item.rs
index 884711f11..3febab32b 100644
--- a/crates/ide_completion/src/item.rs
+++ b/crates/ide_completion/src/item.rs
@@ -2,15 +2,16 @@
 
 use std::fmt;
 
-use hir::{Documentation, ModPath, Mutability};
+use hir::{Documentation, Mutability};
 use ide_db::{
     helpers::{
-        insert_use::{self, ImportScope, MergeBehavior},
+        import_assets::LocatedImport,
+        insert_use::{self, ImportScope, InsertUseConfig},
         mod_path_to_ast, SnippetCap,
     },
     SymbolKind,
 };
-use stdx::{impl_from, never};
+use stdx::{format_to, impl_from, never};
 use syntax::{algo, TextRange};
 use text_edit::TextEdit;
 
@@ -62,12 +63,18 @@ pub struct CompletionItem {
     /// after completion.
     trigger_call_info: bool,
 
-    /// Score is useful to pre select or display in better order completion items
-    score: Option<CompletionScore>,
+    /// We use this to sort completion. Relevance records facts like "do the
+    /// types align precisely?". We can't sort by relevances directly, they are
+    /// only partially ordered.
+    ///
+    /// Note that Relevance ignores fuzzy match score. We compute Relevance for
+    /// all possible items, and then separately build an ordered completion list
+    /// based on relevance and fuzzy matching with the already typed identifier.
+    relevance: CompletionRelevance,
 
     /// Indicates that a reference or mutable reference to this variable is a
     /// possible match.
-    ref_match: Option<(Mutability, CompletionScore)>,
+    ref_match: Option<Mutability>,
 
     /// The import data to add to completion's edits.
     import_to_add: Option<ImportEdit>,
@@ -100,8 +107,13 @@ impl fmt::Debug for CompletionItem {
         if self.deprecated {
             s.field("deprecated", &true);
         }
-        if let Some(score) = &self.score {
-            s.field("score", score);
+
+        if self.relevance != CompletionRelevance::default() {
+            s.field("relevance", &self.relevance);
+        }
+
+        if let Some(mutability) = &self.ref_match {
+            s.field("ref_match", &format!("&{}", mutability.as_keyword_for_ref()));
         }
         if self.trigger_call_info {
             s.field("trigger_call_info", &true);
@@ -110,12 +122,59 @@ impl fmt::Debug for CompletionItem {
     }
 }
 
-#[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq)]
-pub enum CompletionScore {
-    /// If only type match
-    TypeMatch,
-    /// If type and name match
-    TypeAndNameMatch,
+#[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq, Default)]
+pub struct CompletionRelevance {
+    /// This is set in cases like these:
+    ///
+    /// ```
+    /// fn f(spam: String) {}
+    /// fn main {
+    ///     let spam = 92;
+    ///     f($0) // name of local matches the name of param
+    /// }
+    /// ```
+    pub exact_name_match: bool,
+    /// This is set in cases like these:
+    ///
+    /// ```
+    /// fn f(spam: String) {}
+    /// fn main {
+    ///     let foo = String::new();
+    ///     f($0) // type of local matches the type of param
+    /// }
+    /// ```
+    pub exact_type_match: bool,
+}
+
+impl CompletionRelevance {
+    /// Provides a relevance score. Higher values are more relevant.
+    ///
+    /// The absolute value of the relevance score is not meaningful, for
+    /// example a value of 0 doesn't mean "not relevant", rather
+    /// it means "least relevant". The score value should only be used
+    /// for relative ordering.
+    ///
+    /// See is_relevant if you need to make some judgement about score
+    /// in an absolute sense.
+    pub fn score(&self) -> u32 {
+        let mut score = 0;
+
+        if self.exact_name_match {
+            score += 1;
+        }
+        if self.exact_type_match {
+            score += 1;
+        }
+
+        score
+    }
+
+    /// Returns true when the score for this threshold is above
+    /// some threshold such that we think it is especially likely
+    /// to be relevant.
+    pub fn is_relevant(&self) -> bool {
+        self.score() > 0
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -207,9 +266,9 @@ impl CompletionItem {
             lookup: None,
             kind: None,
             text_edit: None,
-            deprecated: None,
+            deprecated: false,
             trigger_call_info: None,
-            score: None,
+            relevance: CompletionRelevance::default(),
             ref_match: None,
             import_to_add: None,
         }
@@ -252,16 +311,22 @@ impl CompletionItem {
         self.deprecated
     }
 
-    pub fn score(&self) -> Option<CompletionScore> {
-        self.score
+    pub fn relevance(&self) -> CompletionRelevance {
+        self.relevance
     }
 
     pub fn trigger_call_info(&self) -> bool {
         self.trigger_call_info
     }
 
-    pub fn ref_match(&self) -> Option<(Mutability, CompletionScore)> {
-        self.ref_match
+    pub fn ref_match(&self) -> Option<(Mutability, CompletionRelevance)> {
+        // Relevance of the ref match should be the same as the original
+        // match, but with exact type match set because self.ref_match
+        // is only set if there is an exact type match.
+        let mut relevance = self.relevance;
+        relevance.exact_type_match = true;
+
+        self.ref_match.map(|mutability| (mutability, relevance))
     }
 
     pub fn import_to_add(&self) -> Option<&ImportEdit> {
@@ -272,22 +337,18 @@ impl CompletionItem {
 /// An extra import to add after the completion is applied.
 #[derive(Debug, Clone)]
 pub struct ImportEdit {
-    pub import_path: ModPath,
-    pub import_scope: ImportScope,
-    pub import_for_trait_assoc_item: bool,
+    pub import: LocatedImport,
+    pub scope: ImportScope,
 }
 
 impl ImportEdit {
     /// Attempts to insert the import to the given scope, producing a text edit.
     /// May return no edit in edge cases, such as scope already containing the import.
-    pub fn to_text_edit(&self, merge_behavior: Option<MergeBehavior>) -> Option<TextEdit> {
+    pub fn to_text_edit(&self, cfg: InsertUseConfig) -> Option<TextEdit> {
         let _p = profile::span("ImportEdit::to_text_edit");
 
-        let rewriter = insert_use::insert_use(
-            &self.import_scope,
-            mod_path_to_ast(&self.import_path),
-            merge_behavior,
-        );
+        let rewriter =
+            insert_use::insert_use(&self.scope, mod_path_to_ast(&self.import.import_path), cfg);
         let old_ast = rewriter.rewrite_root()?;
         let mut import_insert = TextEdit::builder();
         algo::diff(&old_ast, &rewriter.rewrite(&old_ast)).into_text_edit(&mut import_insert);
@@ -311,10 +372,10 @@ pub(crate) struct Builder {
     lookup: Option<String>,
     kind: Option<CompletionItemKind>,
     text_edit: Option<TextEdit>,
-    deprecated: Option<bool>,
+    deprecated: bool,
     trigger_call_info: Option<bool>,
-    score: Option<CompletionScore>,
-    ref_match: Option<(Mutability, CompletionScore)>,
+    relevance: CompletionRelevance,
+    ref_match: Option<Mutability>,
 }
 
 impl Builder {
@@ -325,20 +386,19 @@ impl Builder {
         let mut lookup = self.lookup;
         let mut insert_text = self.insert_text;
 
-        if let Some(import_to_add) = self.import_to_add.as_ref() {
-            if import_to_add.import_for_trait_assoc_item {
-                lookup = lookup.or_else(|| Some(label.clone()));
-                insert_text = insert_text.or_else(|| Some(label.clone()));
-                label = format!("{} ({})", label, import_to_add.import_path);
+        if let Some(original_path) = self
+            .import_to_add
+            .as_ref()
+            .and_then(|import_edit| import_edit.import.original_path.as_ref())
+        {
+            lookup = lookup.or_else(|| Some(label.clone()));
+            insert_text = insert_text.or_else(|| Some(label.clone()));
+
+            let original_path_label = original_path.to_string();
+            if original_path_label.ends_with(&label) {
+                label = original_path_label;
             } else {
-                let mut import_path_without_last_segment = import_to_add.import_path.to_owned();
-                let _ = import_path_without_last_segment.pop_segment();
-
-                if !import_path_without_last_segment.segments().is_empty() {
-                    lookup = lookup.or_else(|| Some(label.clone()));
-                    insert_text = insert_text.or_else(|| Some(label.clone()));
-                    label = format!("{}::{}", import_path_without_last_segment, label);
-                }
+                format_to!(label, " ({})", original_path)
             }
         }
 
@@ -359,49 +419,49 @@ impl Builder {
             lookup,
             kind: self.kind,
             completion_kind: self.completion_kind,
-            deprecated: self.deprecated.unwrap_or(false),
+            deprecated: self.deprecated,
             trigger_call_info: self.trigger_call_info.unwrap_or(false),
-            score: self.score,
+            relevance: self.relevance,
             ref_match: self.ref_match,
             import_to_add: self.import_to_add,
         }
     }
-    pub(crate) fn lookup_by(mut self, lookup: impl Into<String>) -> Builder {
+    pub(crate) fn lookup_by(&mut self, lookup: impl Into<String>) -> &mut Builder {
         self.lookup = Some(lookup.into());
         self
     }
-    pub(crate) fn label(mut self, label: impl Into<String>) -> Builder {
+    pub(crate) fn label(&mut self, label: impl Into<String>) -> &mut Builder {
         self.label = label.into();
         self
     }
-    pub(crate) fn insert_text(mut self, insert_text: impl Into<String>) -> Builder {
+    pub(crate) fn insert_text(&mut self, insert_text: impl Into<String>) -> &mut Builder {
         self.insert_text = Some(insert_text.into());
         self
     }
     pub(crate) fn insert_snippet(
-        mut self,
+        &mut self,
         _cap: SnippetCap,
         snippet: impl Into<String>,
-    ) -> Builder {
+    ) -> &mut Builder {
         self.insert_text_format = InsertTextFormat::Snippet;
         self.insert_text(snippet)
     }
-    pub(crate) fn kind(mut self, kind: impl Into<CompletionItemKind>) -> Builder {
+    pub(crate) fn kind(&mut self, kind: impl Into<CompletionItemKind>) -> &mut Builder {
         self.kind = Some(kind.into());
         self
     }
-    pub(crate) fn text_edit(mut self, edit: TextEdit) -> Builder {
+    pub(crate) fn text_edit(&mut self, edit: TextEdit) -> &mut Builder {
         self.text_edit = Some(edit);
         self
     }
-    pub(crate) fn snippet_edit(mut self, _cap: SnippetCap, edit: TextEdit) -> Builder {
+    pub(crate) fn snippet_edit(&mut self, _cap: SnippetCap, edit: TextEdit) -> &mut Builder {
         self.insert_text_format = InsertTextFormat::Snippet;
         self.text_edit(edit)
     }
-    pub(crate) fn detail(self, detail: impl Into<String>) -> Builder {
+    pub(crate) fn detail(&mut self, detail: impl Into<String>) -> &mut Builder {
         self.set_detail(Some(detail))
     }
-    pub(crate) fn set_detail(mut self, detail: Option<impl Into<String>>) -> Builder {
+    pub(crate) fn set_detail(&mut self, detail: Option<impl Into<String>>) -> &mut Builder {
         self.detail = detail.map(Into::into);
         if let Some(detail) = &self.detail {
             if never!(detail.contains('\n'), "multiline detail:\n{}", detail) {
@@ -411,40 +471,91 @@ impl Builder {
         self
     }
     #[allow(unused)]
-    pub(crate) fn documentation(self, docs: Documentation) -> Builder {
+    pub(crate) fn documentation(&mut self, docs: Documentation) -> &mut Builder {
         self.set_documentation(Some(docs))
     }
-    pub(crate) fn set_documentation(mut self, docs: Option<Documentation>) -> Builder {
+    pub(crate) fn set_documentation(&mut self, docs: Option<Documentation>) -> &mut Builder {
         self.documentation = docs.map(Into::into);
         self
     }
-    pub(crate) fn set_deprecated(mut self, deprecated: bool) -> Builder {
-        self.deprecated = Some(deprecated);
+    pub(crate) fn set_deprecated(&mut self, deprecated: bool) -> &mut Builder {
+        self.deprecated = deprecated;
         self
     }
-    pub(crate) fn set_score(mut self, score: CompletionScore) -> Builder {
-        self.score = Some(score);
+    pub(crate) fn set_relevance(&mut self, relevance: CompletionRelevance) -> &mut Builder {
+        self.relevance = relevance;
         self
     }
-    pub(crate) fn trigger_call_info(mut self) -> Builder {
+    pub(crate) fn trigger_call_info(&mut self) -> &mut Builder {
         self.trigger_call_info = Some(true);
         self
     }
-    pub(crate) fn add_import(mut self, import_to_add: Option<ImportEdit>) -> Builder {
+    pub(crate) fn add_import(&mut self, import_to_add: Option<ImportEdit>) -> &mut Builder {
         self.import_to_add = import_to_add;
         self
     }
-    pub(crate) fn set_ref_match(
-        mut self,
-        ref_match: Option<(Mutability, CompletionScore)>,
-    ) -> Builder {
-        self.ref_match = ref_match;
+    pub(crate) fn ref_match(&mut self, mutability: Mutability) -> &mut Builder {
+        self.ref_match = Some(mutability);
         self
     }
 }
 
-impl<'a> Into<CompletionItem> for Builder {
-    fn into(self) -> CompletionItem {
-        self.build()
+#[cfg(test)]
+mod tests {
+    use itertools::Itertools;
+    use test_utils::assert_eq_text;
+
+    use super::CompletionRelevance;
+
+    /// Check that these are CompletionRelevance are sorted in ascending order
+    /// by their relevance score.
+    ///
+    /// We want to avoid making assertions about the absolute score of any
+    /// item, but we do want to assert whether each is >, <, or == to the
+    /// others.
+    ///
+    /// If provided vec![vec![a], vec![b, c], vec![d]], then this will assert:
+    ///     a.score < b.score == c.score < d.score
+    fn check_relevance_score_ordered(expected_relevance_order: Vec<Vec<CompletionRelevance>>) {
+        let expected = format!("{:#?}", &expected_relevance_order);
+
+        let actual_relevance_order = expected_relevance_order
+            .into_iter()
+            .flatten()
+            .map(|r| (r.score(), r))
+            .sorted_by_key(|(score, _r)| *score)
+            .fold(
+                (u32::MIN, vec![vec![]]),
+                |(mut currently_collecting_score, mut out), (score, r)| {
+                    if currently_collecting_score == score {
+                        out.last_mut().unwrap().push(r);
+                    } else {
+                        currently_collecting_score = score;
+                        out.push(vec![r]);
+                    }
+                    (currently_collecting_score, out)
+                },
+            )
+            .1;
+
+        let actual = format!("{:#?}", &actual_relevance_order);
+
+        assert_eq_text!(&expected, &actual);
+    }
+
+    #[test]
+    fn relevance_score() {
+        // This test asserts that the relevance score for these items is ascending, and
+        // that any items in the same vec have the same score.
+        let expected_relevance_order = vec![
+            vec![CompletionRelevance::default()],
+            vec![
+                CompletionRelevance { exact_name_match: true, ..CompletionRelevance::default() },
+                CompletionRelevance { exact_type_match: true, ..CompletionRelevance::default() },
+            ],
+            vec![CompletionRelevance { exact_name_match: true, exact_type_match: true }],
+        ];
+
+        check_relevance_score_ordered(expected_relevance_order);
     }
 }
diff --git a/crates/ide_completion/src/lib.rs b/crates/ide_completion/src/lib.rs
index 76f31de9e..263554ecf 100644
--- a/crates/ide_completion/src/lib.rs
+++ b/crates/ide_completion/src/lib.rs
@@ -13,7 +13,9 @@ mod completions;
 
 use completions::flyimport::position_for_import;
 use ide_db::{
-    base_db::FilePosition, helpers::insert_use::ImportScope, imports_locator, RootDatabase,
+    base_db::FilePosition,
+    helpers::{import_assets::LocatedImport, insert_use::ImportScope},
+    items_locator, RootDatabase,
 };
 use text_edit::TextEdit;
 
@@ -21,7 +23,7 @@ use crate::{completions::Completions, context::CompletionContext, item::Completi
 
 pub use crate::{
     config::CompletionConfig,
-    item::{CompletionItem, CompletionItemKind, CompletionScore, ImportEdit, InsertTextFormat},
+    item::{CompletionItem, CompletionItemKind, CompletionRelevance, ImportEdit, InsertTextFormat},
 };
 
 //FIXME: split the following feature into fine-grained features.
@@ -139,25 +141,27 @@ pub fn resolve_completion_edits(
     position: FilePosition,
     full_import_path: &str,
     imported_name: String,
-    import_for_trait_assoc_item: bool,
 ) -> Option<Vec<TextEdit>> {
     let ctx = CompletionContext::new(db, position, config)?;
     let position_for_import = position_for_import(&ctx, None)?;
-    let import_scope = ImportScope::find_insert_use_container(position_for_import, &ctx.sema)?;
+    let scope = ImportScope::find_insert_use_container(position_for_import, &ctx.sema)?;
 
     let current_module = ctx.sema.scope(position_for_import).module()?;
     let current_crate = current_module.krate();
 
-    let import_path = imports_locator::find_exact_imports(&ctx.sema, current_crate, imported_name)
-        .filter_map(|candidate| {
-            let item: hir::ItemInNs = candidate.either(Into::into, Into::into);
-            current_module.find_use_path_prefixed(db, item, config.insert_use.prefix_kind)
-        })
-        .find(|mod_path| mod_path.to_string() == full_import_path)?;
+    let (import_path, item_to_import) =
+        items_locator::with_exact_name(&ctx.sema, current_crate, imported_name)
+            .into_iter()
+            .filter_map(|candidate| {
+                current_module
+                    .find_use_path_prefixed(db, candidate, config.insert_use.prefix_kind)
+                    .zip(Some(candidate))
+            })
+            .find(|(mod_path, _)| mod_path.to_string() == full_import_path)?;
+    let import =
+        LocatedImport::new(import_path.clone(), item_to_import, item_to_import, Some(import_path));
 
-    ImportEdit { import_path, import_scope, import_for_trait_assoc_item }
-        .to_text_edit(config.insert_use.merge)
-        .map(|edit| vec![edit])
+    ImportEdit { import, scope }.to_text_edit(config.insert_use).map(|edit| vec![edit])
 }
 
 #[cfg(test)]
diff --git a/crates/ide_completion/src/render.rs b/crates/ide_completion/src/render.rs
index eddaaa6f3..db31896e5 100644
--- a/crates/ide_completion/src/render.rs
+++ b/crates/ide_completion/src/render.rs
@@ -13,13 +13,15 @@ mod builder_ext;
 use hir::{
     AsAssocItem, Documentation, HasAttrs, HirDisplay, ModuleDef, Mutability, ScopeDef, Type,
 };
-use ide_db::{helpers::SnippetCap, RootDatabase, SymbolKind};
+use ide_db::{
+    helpers::{item_name, SnippetCap},
+    RootDatabase, SymbolKind,
+};
 use syntax::TextRange;
-use test_utils::mark;
 
 use crate::{
-    item::ImportEdit, CompletionContext, CompletionItem, CompletionItemKind, CompletionKind,
-    CompletionScore,
+    item::{CompletionRelevance, ImportEdit},
+    CompletionContext, CompletionItem, CompletionItemKind, CompletionKind,
 };
 
 use crate::render::{enum_variant::render_variant, function::render_fn, macro_::render_macro};
@@ -51,18 +53,20 @@ pub(crate) fn render_resolution<'a>(
 pub(crate) fn render_resolution_with_import<'a>(
     ctx: RenderContext<'a>,
     import_edit: ImportEdit,
-    resolution: &ScopeDef,
 ) -> Option<CompletionItem> {
+    let resolution = ScopeDef::from(import_edit.import.original_item);
     let local_name = match resolution {
         ScopeDef::ModuleDef(ModuleDef::Function(f)) => f.name(ctx.completion.db).to_string(),
         ScopeDef::ModuleDef(ModuleDef::Const(c)) => c.name(ctx.completion.db)?.to_string(),
         ScopeDef::ModuleDef(ModuleDef::TypeAlias(t)) => t.name(ctx.completion.db).to_string(),
-        _ => import_edit.import_path.segments().last()?.to_string(),
+        _ => item_name(ctx.db(), import_edit.import.original_item)?.to_string(),
     };
-    Render::new(ctx).render_resolution(local_name, Some(import_edit), resolution).map(|mut item| {
-        item.completion_kind = CompletionKind::Magic;
-        item
-    })
+    Render::new(ctx).render_resolution(local_name, Some(import_edit), &resolution).map(
+        |mut item| {
+            item.completion_kind = CompletionKind::Magic;
+            item
+        },
+    )
 }
 
 /// Interface for data and methods required for items rendering.
@@ -113,13 +117,13 @@ impl<'a> RenderContext<'a> {
         node.docs(self.db())
     }
 
-    fn active_name_and_type(&self) -> Option<(String, Type)> {
+    fn expected_name_and_type(&self) -> Option<(String, Type)> {
         if let Some(record_field) = &self.completion.record_field_syntax {
-            mark::hit!(record_field_type_match);
+            cov_mark::hit!(record_field_type_match);
             let (struct_field, _local) = self.completion.sema.resolve_record_field(record_field)?;
             Some((struct_field.name(self.db()).to_string(), struct_field.signature_ty(self.db())))
         } else if let Some(active_parameter) = &self.completion.active_parameter {
-            mark::hit!(active_param_type_match);
+            cov_mark::hit!(active_param_type_match);
             Some((active_parameter.name.clone(), active_parameter.ty.clone()))
         } else {
             None
@@ -145,24 +149,29 @@ impl<'a> Render<'a> {
             CompletionKind::Reference,
             self.ctx.source_range(),
             name.to_string(),
-        )
-        .kind(SymbolKind::Field)
-        .detail(ty.display(self.ctx.db()).to_string())
-        .set_documentation(field.docs(self.ctx.db()))
-        .set_deprecated(is_deprecated);
+        );
+        item.kind(SymbolKind::Field)
+            .detail(ty.display(self.ctx.db()).to_string())
+            .set_documentation(field.docs(self.ctx.db()))
+            .set_deprecated(is_deprecated);
 
-        if let Some(score) = compute_score(&self.ctx, &ty, &name.to_string()) {
-            item = item.set_score(score);
+        if let Some(relevance) = compute_relevance(&self.ctx, &ty, &name.to_string()) {
+            item.set_relevance(relevance);
         }
 
         item.build()
     }
 
     fn add_tuple_field(&mut self, field: usize, ty: &Type) -> CompletionItem {
-        CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), field.to_string())
-            .kind(SymbolKind::Field)
-            .detail(ty.display(self.ctx.db()).to_string())
-            .build()
+        let mut item = CompletionItem::new(
+            CompletionKind::Reference,
+            self.ctx.source_range(),
+            field.to_string(),
+        );
+
+        item.kind(SymbolKind::Field).detail(ty.display(self.ctx.db()).to_string());
+
+        item.build()
     }
 
     fn render_resolution(
@@ -221,15 +230,13 @@ impl<'a> Render<'a> {
                 CompletionItemKind::SymbolKind(SymbolKind::SelfParam)
             }
             ScopeDef::Unknown => {
-                let item = CompletionItem::new(
+                let mut item = CompletionItem::new(
                     CompletionKind::Reference,
                     self.ctx.source_range(),
                     local_name,
-                )
-                .kind(CompletionItemKind::UnresolvedReference)
-                .add_import(import_to_add)
-                .build();
-                return Some(item);
+                );
+                item.kind(CompletionItemKind::UnresolvedReference).add_import(import_to_add);
+                return Some(item.build());
             }
         };
 
@@ -238,20 +245,27 @@ impl<'a> Render<'a> {
         if let ScopeDef::Local(local) = resolution {
             let ty = local.ty(self.ctx.db());
             if !ty.is_unknown() {
-                item = item.detail(ty.display(self.ctx.db()).to_string());
+                item.detail(ty.display(self.ctx.db()).to_string());
             }
         };
 
-        let mut ref_match = None;
         if let ScopeDef::Local(local) = resolution {
-            if let Some((active_name, active_type)) = self.ctx.active_name_and_type() {
-                let ty = local.ty(self.ctx.db());
-                if let Some(score) =
-                    compute_score_from_active(&active_type, &active_name, &ty, &local_name)
-                {
-                    item = item.set_score(score);
+            let ty = local.ty(self.ctx.db());
+            if let Some(relevance) = compute_relevance(&self.ctx, &ty, &local_name) {
+                item.set_relevance(relevance);
+            }
+            if let Some((_expected_name, expected_type)) = self.ctx.expected_name_and_type() {
+                if let Some(ty_without_ref) = expected_type.remove_ref() {
+                    if ty_without_ref == ty {
+                        cov_mark::hit!(suggest_ref);
+                        let mutability = if expected_type.is_mutable_reference() {
+                            Mutability::Mut
+                        } else {
+                            Mutability::Shared
+                        };
+                        item.ref_match(mutability);
+                    }
                 }
-                ref_match = refed_type_matches(&active_type, &active_name, &ty, &local_name);
             }
         }
 
@@ -269,23 +283,18 @@ impl<'a> Render<'a> {
                     _ => false,
                 };
                 if has_non_default_type_params {
-                    mark::hit!(inserts_angle_brackets_for_generics);
-                    item = item
-                        .lookup_by(local_name.clone())
+                    cov_mark::hit!(inserts_angle_brackets_for_generics);
+                    item.lookup_by(local_name.clone())
                         .label(format!("{}<…>", local_name))
                         .insert_snippet(cap, format!("{}<$0>", local_name));
                 }
             }
         }
-
-        Some(
-            item.kind(kind)
-                .add_import(import_to_add)
-                .set_ref_match(ref_match)
-                .set_documentation(self.docs(resolution))
-                .set_deprecated(self.is_deprecated(resolution))
-                .build(),
-        )
+        item.kind(kind)
+            .add_import(import_to_add)
+            .set_documentation(self.docs(resolution))
+            .set_deprecated(self.is_deprecated(resolution));
+        Some(item.build())
     }
 
     fn docs(&self, resolution: &ScopeDef) -> Option<Documentation> {
@@ -313,56 +322,23 @@ impl<'a> Render<'a> {
     }
 }
 
-fn compute_score_from_active(
-    active_type: &Type,
-    active_name: &str,
-    ty: &Type,
-    name: &str,
-) -> Option<CompletionScore> {
-    // Compute score
-    // For the same type
-    if active_type != ty {
-        return None;
-    }
-
-    let mut res = CompletionScore::TypeMatch;
-
-    // If same type + same name then go top position
-    if active_name == name {
-        res = CompletionScore::TypeAndNameMatch
-    }
-
+fn compute_relevance(ctx: &RenderContext, ty: &Type, name: &str) -> Option<CompletionRelevance> {
+    let (expected_name, expected_type) = ctx.expected_name_and_type()?;
+    let mut res = CompletionRelevance::default();
+    res.exact_type_match = ty == &expected_type;
+    res.exact_name_match = name == &expected_name;
     Some(res)
 }
-fn refed_type_matches(
-    active_type: &Type,
-    active_name: &str,
-    ty: &Type,
-    name: &str,
-) -> Option<(Mutability, CompletionScore)> {
-    let derefed_active = active_type.remove_ref()?;
-    let score = compute_score_from_active(&derefed_active, &active_name, &ty, &name)?;
-    Some((
-        if active_type.is_mutable_reference() { Mutability::Mut } else { Mutability::Shared },
-        score,
-    ))
-}
-
-fn compute_score(ctx: &RenderContext, ty: &Type, name: &str) -> Option<CompletionScore> {
-    let (active_name, active_type) = ctx.active_name_and_type()?;
-    compute_score_from_active(&active_type, &active_name, ty, name)
-}
 
 #[cfg(test)]
 mod tests {
     use std::cmp::Reverse;
 
     use expect_test::{expect, Expect};
-    use test_utils::mark;
 
     use crate::{
         test_utils::{check_edit, do_completion, get_all_items, TEST_CONFIG},
-        CompletionKind, CompletionScore,
+        CompletionKind, CompletionRelevance,
     };
 
     fn check(ra_fixture: &str, expect: Expect) {
@@ -370,24 +346,27 @@ mod tests {
         expect.assert_debug_eq(&actual);
     }
 
-    fn check_scores(ra_fixture: &str, expect: Expect) {
-        fn display_score(score: Option<CompletionScore>) -> &'static str {
-            match score {
-                Some(CompletionScore::TypeMatch) => "[type]",
-                Some(CompletionScore::TypeAndNameMatch) => "[type+name]",
-                None => "[]".into(),
+    fn check_relevance(ra_fixture: &str, expect: Expect) {
+        fn display_relevance(relevance: CompletionRelevance) -> &'static str {
+            match relevance {
+                CompletionRelevance { exact_type_match: true, exact_name_match: true } => {
+                    "[type+name]"
+                }
+                CompletionRelevance { exact_type_match: true, exact_name_match: false } => "[type]",
+                CompletionRelevance { exact_type_match: false, exact_name_match: true } => "[name]",
+                CompletionRelevance { exact_type_match: false, exact_name_match: false } => "[]",
             }
         }
 
         let mut completions = get_all_items(TEST_CONFIG, ra_fixture);
-        completions.sort_by_key(|it| (Reverse(it.score()), it.label().to_string()));
+        completions.sort_by_key(|it| (Reverse(it.relevance()), it.label().to_string()));
         let actual = completions
             .into_iter()
             .filter(|it| it.completion_kind == CompletionKind::Reference)
             .map(|it| {
                 let tag = it.kind().unwrap().tag();
-                let score = display_score(it.score());
-                format!("{} {} {}\n", tag, it.label(), score)
+                let relevance = display_relevance(it.relevance());
+                format!("{} {} {}\n", tag, it.label(), relevance)
             })
             .collect::<String>();
         expect.assert_eq(&actual);
@@ -734,7 +713,7 @@ fn foo(s: S) { s.$0 }
 
     #[test]
     fn no_call_parens_if_fn_ptr_needed() {
-        mark::check!(no_call_parens_if_fn_ptr_needed);
+        cov_mark::check!(no_call_parens_if_fn_ptr_needed);
         check_edit(
             "foo",
             r#"
@@ -758,7 +737,7 @@ fn main() -> ManualVtable {
 
     #[test]
     fn no_parens_in_use_item() {
-        mark::check!(no_parens_in_use_item);
+        cov_mark::check!(no_parens_in_use_item);
         check_edit(
             "foo",
             r#"
@@ -802,7 +781,7 @@ fn f(foo: &Foo) { foo.foo(); }
 
     #[test]
     fn inserts_angle_brackets_for_generics() {
-        mark::check!(inserts_angle_brackets_for_generics);
+        cov_mark::check!(inserts_angle_brackets_for_generics);
         check_edit(
             "Vec",
             r#"
@@ -850,9 +829,9 @@ fn foo(xs: Vec<i128>)
     }
 
     #[test]
-    fn active_param_score() {
-        mark::check!(active_param_type_match);
-        check_scores(
+    fn active_param_relevance() {
+        cov_mark::check!(active_param_type_match);
+        check_relevance(
             r#"
 struct S { foo: i64, bar: u32, baz: u32 }
 fn test(bar: u32) { }
@@ -867,9 +846,9 @@ fn foo(s: S) { test(s.$0) }
     }
 
     #[test]
-    fn record_field_scores() {
-        mark::check!(record_field_type_match);
-        check_scores(
+    fn record_field_relevances() {
+        cov_mark::check!(record_field_type_match);
+        check_relevance(
             r#"
 struct A { foo: i64, bar: u32, baz: u32 }
 struct B { x: (), y: f32, bar: u32 }
@@ -884,8 +863,8 @@ fn foo(a: A) { B { bar: a.$0 }; }
     }
 
     #[test]
-    fn record_field_and_call_scores() {
-        check_scores(
+    fn record_field_and_call_relevances() {
+        check_relevance(
             r#"
 struct A { foo: i64, bar: u32, baz: u32 }
 struct B { x: (), y: f32, bar: u32 }
@@ -898,7 +877,7 @@ fn foo(a: A) { B { bar: f(a.$0) }; }
                 fd baz []
             "#]],
         );
-        check_scores(
+        check_relevance(
             r#"
 struct A { foo: i64, bar: u32, baz: u32 }
 struct B { x: (), y: f32, bar: u32 }
@@ -915,7 +894,7 @@ fn foo(a: A) { f(B { bar: a.$0 }); }
 
     #[test]
     fn prioritize_exact_ref_match() {
-        check_scores(
+        check_relevance(
             r#"
 struct WorldSnapshot { _f: () };
 fn go(world: &WorldSnapshot) { go(w$0) }
@@ -930,7 +909,7 @@ fn go(world: &WorldSnapshot) { go(w$0) }
 
     #[test]
     fn too_many_arguments() {
-        check_scores(
+        check_relevance(
             r#"
 struct Foo;
 fn f(foo: &Foo) { f(foo, w$0) }
@@ -942,4 +921,70 @@ fn f(foo: &Foo) { f(foo, w$0) }
             "#]],
         );
     }
+
+    #[test]
+    fn suggest_ref_mut() {
+        cov_mark::check!(suggest_ref);
+        check(
+            r#"
+struct S;
+fn foo(s: &mut S) {}
+fn main() {
+    let mut s = S;
+    foo($0);
+}
+            "#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "S",
+                        source_range: 70..70,
+                        delete: 70..70,
+                        insert: "S",
+                        kind: SymbolKind(
+                            Struct,
+                        ),
+                    },
+                    CompletionItem {
+                        label: "foo(…)",
+                        source_range: 70..70,
+                        delete: 70..70,
+                        insert: "foo(${1:&mut s})$0",
+                        kind: SymbolKind(
+                            Function,
+                        ),
+                        lookup: "foo",
+                        detail: "-> ()",
+                        trigger_call_info: true,
+                    },
+                    CompletionItem {
+                        label: "main()",
+                        source_range: 70..70,
+                        delete: 70..70,
+                        insert: "main()$0",
+                        kind: SymbolKind(
+                            Function,
+                        ),
+                        lookup: "main",
+                        detail: "-> ()",
+                    },
+                    CompletionItem {
+                        label: "s",
+                        source_range: 70..70,
+                        delete: 70..70,
+                        insert: "s",
+                        kind: SymbolKind(
+                            Local,
+                        ),
+                        detail: "S",
+                        relevance: CompletionRelevance {
+                            exact_name_match: true,
+                            exact_type_match: false,
+                        },
+                        ref_match: "&mut ",
+                    },
+                ]
+            "#]],
+        )
+    }
 }
diff --git a/crates/ide_completion/src/render/builder_ext.rs b/crates/ide_completion/src/render/builder_ext.rs
index d053a988b..6d062b3b9 100644
--- a/crates/ide_completion/src/render/builder_ext.rs
+++ b/crates/ide_completion/src/render/builder_ext.rs
@@ -1,7 +1,6 @@
 //! Extensions for `Builder` structure required for item rendering.
 
 use itertools::Itertools;
-use test_utils::mark;
 
 use crate::{item::Builder, CompletionContext};
 
@@ -30,7 +29,7 @@ impl Builder {
             return false;
         }
         if ctx.use_item_syntax.is_some() {
-            mark::hit!(no_parens_in_use_item);
+            cov_mark::hit!(no_parens_in_use_item);
             return false;
         }
         if ctx.is_pattern_call {
@@ -43,7 +42,7 @@ impl Builder {
         // Don't add parentheses if the expected type is some function reference.
         if let Some(ty) = &ctx.expected_type {
             if ty.is_fn() {
-                mark::hit!(no_call_parens_if_fn_ptr_needed);
+                cov_mark::hit!(no_call_parens_if_fn_ptr_needed);
                 return false;
             }
         }
@@ -53,11 +52,11 @@ impl Builder {
     }
 
     pub(super) fn add_call_parens(
-        mut self,
+        &mut self,
         ctx: &CompletionContext,
         name: String,
         params: Params,
-    ) -> Builder {
+    ) -> &mut Builder {
         if !self.should_add_parens(ctx) {
             return self;
         }
@@ -67,12 +66,12 @@ impl Builder {
             None => return self,
         };
         // If not an import, add parenthesis automatically.
-        mark::hit!(inserts_parens_for_function_calls);
+        cov_mark::hit!(inserts_parens_for_function_calls);
 
         let (snippet, label) = if params.is_empty() {
             (format!("{}()$0", name), format!("{}()", name))
         } else {
-            self = self.trigger_call_info();
+            self.trigger_call_info();
             let snippet = match (ctx.config.add_call_argument_snippets, params) {
                 (true, Params::Named(params)) => {
                     let function_params_snippet =
@@ -82,7 +81,7 @@ impl Builder {
                     format!("{}({})$0", name, function_params_snippet)
                 }
                 _ => {
-                    mark::hit!(suppress_arg_snippets);
+                    cov_mark::hit!(suppress_arg_snippets);
                     format!("{}($0)", name)
                 }
             };
diff --git a/crates/ide_completion/src/render/const_.rs b/crates/ide_completion/src/render/const_.rs
index 5010b642a..8add369e4 100644
--- a/crates/ide_completion/src/render/const_.rs
+++ b/crates/ide_completion/src/render/const_.rs
@@ -36,17 +36,17 @@ impl<'a> ConstRender<'a> {
         let name = self.name()?;
         let detail = self.detail();
 
-        let item = CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name)
-            .kind(SymbolKind::Const)
+        let mut item =
+            CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name);
+        item.kind(SymbolKind::Const)
             .set_documentation(self.ctx.docs(self.const_))
             .set_deprecated(
                 self.ctx.is_deprecated(self.const_)
                     || self.ctx.is_deprecated_assoc_item(self.const_),
             )
-            .detail(detail)
-            .build();
+            .detail(detail);
 
-        Some(item)
+        Some(item.build())
     }
 
     fn name(&self) -> Option<String> {
diff --git a/crates/ide_completion/src/render/enum_variant.rs b/crates/ide_completion/src/render/enum_variant.rs
index 9214193b4..e8cfcc0c7 100644
--- a/crates/ide_completion/src/render/enum_variant.rs
+++ b/crates/ide_completion/src/render/enum_variant.rs
@@ -3,7 +3,6 @@
 use hir::{HasAttrs, HirDisplay, ModPath, StructKind};
 use ide_db::SymbolKind;
 use itertools::Itertools;
-use test_utils::mark;
 
 use crate::{
     item::{CompletionItem, CompletionKind, ImportEdit},
@@ -56,27 +55,26 @@ impl<'a> EnumRender<'a> {
     }
 
     fn render(self, import_to_add: Option<ImportEdit>) -> CompletionItem {
-        let mut builder = CompletionItem::new(
+        let mut item = CompletionItem::new(
             CompletionKind::Reference,
             self.ctx.source_range(),
             self.qualified_name.clone(),
-        )
-        .kind(SymbolKind::Variant)
-        .set_documentation(self.variant.docs(self.ctx.db()))
-        .set_deprecated(self.ctx.is_deprecated(self.variant))
-        .add_import(import_to_add)
-        .detail(self.detail());
+        );
+        item.kind(SymbolKind::Variant)
+            .set_documentation(self.variant.docs(self.ctx.db()))
+            .set_deprecated(self.ctx.is_deprecated(self.variant))
+            .add_import(import_to_add)
+            .detail(self.detail());
 
         if self.variant_kind == StructKind::Tuple {
-            mark::hit!(inserts_parens_for_tuple_enums);
+            cov_mark::hit!(inserts_parens_for_tuple_enums);
             let params = Params::Anonymous(self.variant.fields(self.ctx.db()).len());
-            builder =
-                builder.add_call_parens(self.ctx.completion, self.short_qualified_name, params);
+            item.add_call_parens(self.ctx.completion, self.short_qualified_name, params);
         } else if self.path.is_some() {
-            builder = builder.lookup_by(self.short_qualified_name);
+            item.lookup_by(self.short_qualified_name);
         }
 
-        builder.build()
+        item.build()
     }
 
     fn detail(&self) -> String {
@@ -103,13 +101,11 @@ impl<'a> EnumRender<'a> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::test_utils::check_edit;
 
     #[test]
     fn inserts_parens_for_tuple_enums() {
-        mark::check!(inserts_parens_for_tuple_enums);
+        cov_mark::check!(inserts_parens_for_tuple_enums);
         check_edit(
             "Some",
             r#"
diff --git a/crates/ide_completion/src/render/function.rs b/crates/ide_completion/src/render/function.rs
index e46e21d24..f4dabe3d1 100644
--- a/crates/ide_completion/src/render/function.rs
+++ b/crates/ide_completion/src/render/function.rs
@@ -3,7 +3,6 @@
 use hir::{HasSource, HirDisplay, Type};
 use ide_db::SymbolKind;
 use syntax::ast::Fn;
-use test_utils::mark;
 
 use crate::{
     item::{CompletionItem, CompletionItemKind, CompletionKind, ImportEdit},
@@ -42,16 +41,21 @@ impl<'a> FunctionRender<'a> {
 
     fn render(self, import_to_add: Option<ImportEdit>) -> CompletionItem {
         let params = self.params();
-        CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), self.name.clone())
-            .kind(self.kind())
+        let mut item = CompletionItem::new(
+            CompletionKind::Reference,
+            self.ctx.source_range(),
+            self.name.clone(),
+        );
+        item.kind(self.kind())
             .set_documentation(self.ctx.docs(self.func))
             .set_deprecated(
                 self.ctx.is_deprecated(self.func) || self.ctx.is_deprecated_assoc_item(self.func),
             )
             .detail(self.detail())
             .add_call_parens(self.ctx.completion, self.name, params)
-            .add_import(import_to_add)
-            .build()
+            .add_import(import_to_add);
+
+        item.build()
     }
 
     fn detail(&self) -> String {
@@ -82,7 +86,7 @@ impl<'a> FunctionRender<'a> {
             self.func.method_params(self.ctx.db()).unwrap_or_default()
         } else {
             if let Some(s) = ast_params.self_param() {
-                mark::hit!(parens_for_method_call_as_assoc_fn);
+                cov_mark::hit!(parens_for_method_call_as_assoc_fn);
                 params_pats.push(Some(s.to_string()));
             }
             self.func.assoc_fn_params(self.ctx.db())
@@ -114,8 +118,6 @@ impl<'a> FunctionRender<'a> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::{
         test_utils::{check_edit, check_edit_with_config, TEST_CONFIG},
         CompletionConfig,
@@ -123,7 +125,7 @@ mod tests {
 
     #[test]
     fn inserts_parens_for_function_calls() {
-        mark::check!(inserts_parens_for_function_calls);
+        cov_mark::check!(inserts_parens_for_function_calls);
         check_edit(
             "no_args",
             r#"
@@ -191,7 +193,7 @@ fn bar(s: &S) {
 
     #[test]
     fn parens_for_method_call_as_assoc_fn() {
-        mark::check!(parens_for_method_call_as_assoc_fn);
+        cov_mark::check!(parens_for_method_call_as_assoc_fn);
         check_edit(
             "foo",
             r#"
@@ -213,7 +215,7 @@ fn main() { S::foo(${1:&self})$0 }
 
     #[test]
     fn suppress_arg_snippets() {
-        mark::check!(suppress_arg_snippets);
+        cov_mark::check!(suppress_arg_snippets);
         check_edit_with_config(
             CompletionConfig { add_call_argument_snippets: false, ..TEST_CONFIG },
             "with_args",
diff --git a/crates/ide_completion/src/render/macro_.rs b/crates/ide_completion/src/render/macro_.rs
index a4535786f..3fa21ba7c 100644
--- a/crates/ide_completion/src/render/macro_.rs
+++ b/crates/ide_completion/src/render/macro_.rs
@@ -3,7 +3,6 @@
 use hir::{Documentation, HasSource};
 use ide_db::SymbolKind;
 use syntax::display::macro_label;
-use test_utils::mark;
 
 use crate::{
     item::{CompletionItem, CompletionKind, ImportEdit},
@@ -40,29 +39,31 @@ impl<'a> MacroRender<'a> {
     }
 
     fn render(&self, import_to_add: Option<ImportEdit>) -> Option<CompletionItem> {
-        let mut builder =
-            CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), &self.label())
-                .kind(SymbolKind::Macro)
-                .set_documentation(self.docs.clone())
-                .set_deprecated(self.ctx.is_deprecated(self.macro_))
-                .add_import(import_to_add)
-                .set_detail(self.detail());
+        let mut item =
+            CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), &self.label());
+        item.kind(SymbolKind::Macro)
+            .set_documentation(self.docs.clone())
+            .set_deprecated(self.ctx.is_deprecated(self.macro_))
+            .add_import(import_to_add)
+            .set_detail(self.detail());
 
         let needs_bang = self.needs_bang();
-        builder = match self.ctx.snippet_cap() {
+        match self.ctx.snippet_cap() {
             Some(cap) if needs_bang => {
                 let snippet = self.snippet();
                 let lookup = self.lookup();
-                builder.insert_snippet(cap, snippet).lookup_by(lookup)
+                item.insert_snippet(cap, snippet).lookup_by(lookup);
+            }
+            None if needs_bang => {
+                item.insert_text(self.banged_name());
             }
-            None if needs_bang => builder.insert_text(self.banged_name()),
             _ => {
-                mark::hit!(dont_insert_macro_call_parens_unncessary);
-                builder.insert_text(&self.name)
+                cov_mark::hit!(dont_insert_macro_call_parens_unncessary);
+                item.insert_text(&self.name);
             }
         };
 
-        Some(builder.build())
+        Some(item.build())
     }
 
     fn needs_bang(&self) -> bool {
@@ -125,13 +126,11 @@ fn guess_macro_braces(macro_name: &str, docs: &str) -> (&'static str, &'static s
 
 #[cfg(test)]
 mod tests {
-    use test_utils::mark;
-
     use crate::test_utils::check_edit;
 
     #[test]
     fn dont_insert_macro_call_parens_unncessary() {
-        mark::check!(dont_insert_macro_call_parens_unncessary);
+        cov_mark::check!(dont_insert_macro_call_parens_unncessary);
         check_edit(
             "frobnicate!",
             r#"
diff --git a/crates/ide_completion/src/render/pattern.rs b/crates/ide_completion/src/render/pattern.rs
index 465dfe00c..ca2926125 100644
--- a/crates/ide_completion/src/render/pattern.rs
+++ b/crates/ide_completion/src/render/pattern.rs
@@ -69,19 +69,19 @@ fn build_completion(
     ctx: RenderContext<'_>,
     name: String,
     pat: String,
-    item: impl HasAttrs + Copy,
+    def: impl HasAttrs + Copy,
 ) -> CompletionItem {
-    let completion = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), name)
-        .kind(CompletionItemKind::Binding)
-        .set_documentation(ctx.docs(item))
-        .set_deprecated(ctx.is_deprecated(item))
+    let mut item = CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), name);
+    item.kind(CompletionItemKind::Binding)
+        .set_documentation(ctx.docs(def))
+        .set_deprecated(ctx.is_deprecated(def))
         .detail(&pat);
-    let completion = if let Some(snippet_cap) = ctx.snippet_cap() {
-        completion.insert_snippet(snippet_cap, pat)
+    if let Some(snippet_cap) = ctx.snippet_cap() {
+        item.insert_snippet(snippet_cap, pat);
     } else {
-        completion.insert_text(pat)
+        item.insert_text(pat);
     };
-    completion.build()
+    item.build()
 }
 
 fn render_pat(
diff --git a/crates/ide_completion/src/render/type_alias.rs b/crates/ide_completion/src/render/type_alias.rs
index bd97c3692..e47b4c745 100644
--- a/crates/ide_completion/src/render/type_alias.rs
+++ b/crates/ide_completion/src/render/type_alias.rs
@@ -36,17 +36,17 @@ impl<'a> TypeAliasRender<'a> {
         let name = self.name()?;
         let detail = self.detail();
 
-        let item = CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name)
-            .kind(SymbolKind::TypeAlias)
+        let mut item =
+            CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name);
+        item.kind(SymbolKind::TypeAlias)
             .set_documentation(self.ctx.docs(self.type_alias))
             .set_deprecated(
                 self.ctx.is_deprecated(self.type_alias)
                     || self.ctx.is_deprecated_assoc_item(self.type_alias),
             )
-            .detail(detail)
-            .build();
+            .detail(detail);
 
-        Some(item)
+        Some(item.build())
     }
 
     fn name(&self) -> Option<String> {
diff --git a/crates/ide_completion/src/test_utils.rs b/crates/ide_completion/src/test_utils.rs
index baff83305..9da844031 100644
--- a/crates/ide_completion/src/test_utils.rs
+++ b/crates/ide_completion/src/test_utils.rs
@@ -25,6 +25,7 @@ pub(crate) const TEST_CONFIG: CompletionConfig = CompletionConfig {
     insert_use: InsertUseConfig {
         merge: Some(MergeBehavior::Full),
         prefix_kind: PrefixKind::Plain,
+        group: true,
     },
 };
 
@@ -119,7 +120,7 @@ pub(crate) fn check_edit_with_config(
 
     let mut combined_edit = completion.text_edit().to_owned();
     if let Some(import_text_edit) =
-        completion.import_to_add().and_then(|edit| edit.to_text_edit(config.insert_use.merge))
+        completion.import_to_add().and_then(|edit| edit.to_text_edit(config.insert_use))
     {
         combined_edit.union(import_text_edit).expect(
             "Failed to apply completion resolve changes: change ranges overlap, but should not",
diff --git a/crates/ide_db/Cargo.toml b/crates/ide_db/Cargo.toml
index d4612a75e..1f7a90d20 100644
--- a/crates/ide_db/Cargo.toml
+++ b/crates/ide_db/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 log = "0.4.8"
 rayon = "1.5.0"
 fst = { version = "0.4", default-features = false }
@@ -23,10 +24,10 @@ syntax = { path = "../syntax", version = "0.0.0" }
 text_edit = { path = "../text_edit", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 # ide should depend only on the top-level `hir` package. if you need
 # something from some `hir_xxx` subpackage, reexport the API via `hir`.
 hir = { path = "../hir", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide_db/src/call_info.rs b/crates/ide_db/src/call_info.rs
index 615fa7b0e..d8878aa91 100644
--- a/crates/ide_db/src/call_info.rs
+++ b/crates/ide_db/src/call_info.rs
@@ -7,7 +7,6 @@ use syntax::{
     ast::{self, ArgListOwner},
     match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
-use test_utils::mark;
 
 use crate::RootDatabase;
 
@@ -122,7 +121,7 @@ fn call_info_impl(
 
         let arg_list_range = arg_list.syntax().text_range();
         if !arg_list_range.contains_inclusive(token.text_range().start()) {
-            mark::hit!(call_info_bad_offset);
+            cov_mark::hit!(call_info_bad_offset);
             return None;
         }
         let param = std::cmp::min(
@@ -162,7 +161,7 @@ impl ActiveParameter {
         let idx = active_parameter?;
         let mut params = signature.params(sema.db);
         if !(idx < params.len()) {
-            mark::hit!(too_many_arguments);
+            cov_mark::hit!(too_many_arguments);
             return None;
         }
         let (pat, ty) = params.swap_remove(idx);
diff --git a/crates/ide_db/src/call_info/tests.rs b/crates/ide_db/src/call_info/tests.rs
index c714cf280..9f84c253c 100644
--- a/crates/ide_db/src/call_info/tests.rs
+++ b/crates/ide_db/src/call_info/tests.rs
@@ -1,7 +1,7 @@
 use crate::RootDatabase;
 use base_db::{fixture::ChangeFixture, FilePosition};
 use expect_test::{expect, Expect};
-use test_utils::{mark, RangeOrOffset};
+use test_utils::RangeOrOffset;
 
 /// Creates analysis from a multi-file fixture, returns positions marked with $0.
 pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
@@ -347,7 +347,7 @@ pub fn foo(mut r: WriteHandler<()>) {
 
 #[test]
 fn call_info_bad_offset() {
-    mark::check!(call_info_bad_offset);
+    cov_mark::check!(call_info_bad_offset);
     check(
         r#"
 fn foo(x: u32, y: u32) -> u32 {x + y}
diff --git a/crates/ide_db/src/helpers.rs b/crates/ide_db/src/helpers.rs
index 3ff77400b..3c95d3cff 100644
--- a/crates/ide_db/src/helpers.rs
+++ b/crates/ide_db/src/helpers.rs
@@ -2,11 +2,19 @@
 pub mod insert_use;
 pub mod import_assets;
 
-use hir::{Crate, Enum, Module, ScopeDef, Semantics, Trait};
+use hir::{Crate, Enum, ItemInNs, MacroDef, Module, ModuleDef, Name, ScopeDef, Semantics, Trait};
 use syntax::ast::{self, make};
 
 use crate::RootDatabase;
 
+pub fn item_name(db: &RootDatabase, item: ItemInNs) -> Option<Name> {
+    match item {
+        ItemInNs::Types(module_def_id) => ModuleDef::from(module_def_id).name(db),
+        ItemInNs::Values(module_def_id) => ModuleDef::from(module_def_id).name(db),
+        ItemInNs::Macros(macro_def_id) => MacroDef::from(macro_def_id).name(db),
+    }
+}
+
 /// Converts the mod path struct into its ast representation.
 pub fn mod_path_to_ast(path: &hir::ModPath) -> ast::Path {
     let _p = profile::span("mod_path_to_ast");
diff --git a/crates/ide_db/src/helpers/import_assets.rs b/crates/ide_db/src/helpers/import_assets.rs
index 517abbb4b..e03ccd351 100644
--- a/crates/ide_db/src/helpers/import_assets.rs
+++ b/crates/ide_db/src/helpers/import_assets.rs
@@ -1,19 +1,29 @@
 //! Look up accessible paths for items.
-use either::Either;
-use hir::{AsAssocItem, AssocItem, Crate, MacroDef, Module, ModuleDef, PrefixKind, Semantics};
+use hir::{
+    AsAssocItem, AssocItem, AssocItemContainer, Crate, ItemInNs, MacroDef, ModPath, Module,
+    ModuleDef, PathResolution, PrefixKind, ScopeDef, Semantics, Type,
+};
+use itertools::Itertools;
 use rustc_hash::FxHashSet;
-use syntax::{ast, AstNode};
+use syntax::{ast, utils::path_to_string_stripping_turbo_fish, AstNode, SyntaxNode};
 
 use crate::{
-    imports_locator::{self, AssocItemSearch, DEFAULT_QUERY_SEARCH_LIMIT},
+    items_locator::{self, AssocItemSearch, DEFAULT_QUERY_SEARCH_LIMIT},
     RootDatabase,
 };
 
+use super::item_name;
+
+/// A candidate for import, derived during various IDE activities:
+/// * completion with imports on the fly proposals
+/// * completion edit resolve requests
+/// * assists
+/// * etc.
 #[derive(Debug)]
 pub enum ImportCandidate {
-    // A path, qualified (`std::collections::HashMap`) or not (`HashMap`).
+    /// A path, qualified (`std::collections::HashMap`) or not (`HashMap`).
     Path(PathImportCandidate),
-    /// A trait associated function (with no self parameter) or associated constant.
+    /// A trait associated function (with no self parameter) or an associated constant.
     /// For 'test_mod::TestEnum::test_function', `ty` is the `test_mod::TestEnum` expression type
     /// and `name` is the `test_function`
     TraitAssocItem(TraitImportCandidate),
@@ -23,21 +33,40 @@ pub enum ImportCandidate {
     TraitMethod(TraitImportCandidate),
 }
 
+/// A trait import needed for a given associated item access.
+/// For `some::path::SomeStruct::ASSOC_`, contains the
+/// type of `some::path::SomeStruct` and `ASSOC_` as the item name.
 #[derive(Debug)]
 pub struct TraitImportCandidate {
-    pub receiver_ty: hir::Type,
-    pub name: NameToImport,
+    /// A type of the item that has the associated item accessed at.
+    pub receiver_ty: Type,
+    /// The associated item name that the trait to import should contain.
+    pub assoc_item_name: NameToImport,
 }
 
+/// Path import for a given name, qualified or not.
 #[derive(Debug)]
 pub struct PathImportCandidate {
-    pub qualifier: Option<ast::Path>,
+    /// Optional qualifier before name.
+    pub qualifier: Option<FirstSegmentUnresolved>,
+    /// The name the item (struct, trait, enum, etc.) should have.
     pub name: NameToImport,
 }
 
+/// A qualifier that has a first segment and it's unresolved.
+#[derive(Debug)]
+pub struct FirstSegmentUnresolved {
+    fist_segment: ast::NameRef,
+    full_qualifier: ast::Path,
+}
+
+/// A name that will be used during item lookups.
 #[derive(Debug)]
 pub enum NameToImport {
+    /// Requires items with names that exactly match the given string, case-sensitive.
     Exact(String),
+    /// Requires items with names that case-insensitively contain all letters from the string,
+    /// in the same order, but not necessary adjacent.
     Fuzzy(String),
 }
 
@@ -50,10 +79,12 @@ impl NameToImport {
     }
 }
 
+/// A struct to find imports in the project, given a certain name (or its part) and the context.
 #[derive(Debug)]
 pub struct ImportAssets {
     import_candidate: ImportCandidate,
-    module_with_candidate: hir::Module,
+    candidate_node: SyntaxNode,
+    module_with_candidate: Module,
 }
 
 impl ImportAssets {
@@ -61,9 +92,11 @@ impl ImportAssets {
         method_call: &ast::MethodCallExpr,
         sema: &Semantics<RootDatabase>,
     ) -> Option<Self> {
+        let candidate_node = method_call.syntax().clone();
         Some(Self {
             import_candidate: ImportCandidate::for_method_call(sema, method_call)?,
-            module_with_candidate: sema.scope(method_call.syntax()).module()?,
+            module_with_candidate: sema.scope(&candidate_node).module()?,
+            candidate_node,
         })
     }
 
@@ -71,94 +104,94 @@ impl ImportAssets {
         fully_qualified_path: &ast::Path,
         sema: &Semantics<RootDatabase>,
     ) -> Option<Self> {
-        let syntax_under_caret = fully_qualified_path.syntax();
-        if syntax_under_caret.ancestors().find_map(ast::Use::cast).is_some() {
+        let candidate_node = fully_qualified_path.syntax().clone();
+        if candidate_node.ancestors().find_map(ast::Use::cast).is_some() {
             return None;
         }
         Some(Self {
             import_candidate: ImportCandidate::for_regular_path(sema, fully_qualified_path)?,
-            module_with_candidate: sema.scope(syntax_under_caret).module()?,
+            module_with_candidate: sema.scope(&candidate_node).module()?,
+            candidate_node,
         })
     }
 
     pub fn for_fuzzy_path(
-        module_with_path: Module,
+        module_with_candidate: Module,
         qualifier: Option<ast::Path>,
         fuzzy_name: String,
         sema: &Semantics<RootDatabase>,
+        candidate_node: SyntaxNode,
     ) -> Option<Self> {
-        Some(match qualifier {
-            Some(qualifier) => {
-                let qualifier_resolution = sema.resolve_path(&qualifier)?;
-                match qualifier_resolution {
-                    hir::PathResolution::Def(hir::ModuleDef::Adt(assoc_item_path)) => Self {
-                        import_candidate: ImportCandidate::TraitAssocItem(TraitImportCandidate {
-                            receiver_ty: assoc_item_path.ty(sema.db),
-                            name: NameToImport::Fuzzy(fuzzy_name),
-                        }),
-                        module_with_candidate: module_with_path,
-                    },
-                    _ => Self {
-                        import_candidate: ImportCandidate::Path(PathImportCandidate {
-                            qualifier: Some(qualifier),
-                            name: NameToImport::Fuzzy(fuzzy_name),
-                        }),
-                        module_with_candidate: module_with_path,
-                    },
-                }
-            }
-            None => Self {
-                import_candidate: ImportCandidate::Path(PathImportCandidate {
-                    qualifier: None,
-                    name: NameToImport::Fuzzy(fuzzy_name),
-                }),
-                module_with_candidate: module_with_path,
-            },
+        Some(Self {
+            import_candidate: ImportCandidate::for_fuzzy_path(qualifier, fuzzy_name, sema)?,
+            module_with_candidate,
+            candidate_node,
         })
     }
 
     pub fn for_fuzzy_method_call(
         module_with_method_call: Module,
-        receiver_ty: hir::Type,
+        receiver_ty: Type,
         fuzzy_method_name: String,
+        candidate_node: SyntaxNode,
     ) -> Option<Self> {
         Some(Self {
             import_candidate: ImportCandidate::TraitMethod(TraitImportCandidate {
                 receiver_ty,
-                name: NameToImport::Fuzzy(fuzzy_method_name),
+                assoc_item_name: NameToImport::Fuzzy(fuzzy_method_name),
             }),
             module_with_candidate: module_with_method_call,
+            candidate_node,
         })
     }
 }
 
+/// An import (not necessary the only one) that corresponds a certain given [`PathImportCandidate`].
+/// (the structure is not entirely correct, since there can be situations requiring two imports, see FIXME below for the details)
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct LocatedImport {
+    /// The path to use in the `use` statement for a given candidate to be imported.
+    pub import_path: ModPath,
+    /// An item that will be imported with the import path given.
+    pub item_to_import: ItemInNs,
+    /// The path import candidate, resolved.
+    ///
+    /// Not necessary matches the import:
+    /// For any associated constant from the trait, we try to access as `some::path::SomeStruct::ASSOC_`
+    /// the original item is the associated constant, but the import has to be a trait that
+    /// defines this constant.
+    pub original_item: ItemInNs,
+    /// A path of the original item.
+    pub original_path: Option<ModPath>,
+}
+
+impl LocatedImport {
+    pub fn new(
+        import_path: ModPath,
+        item_to_import: ItemInNs,
+        original_item: ItemInNs,
+        original_path: Option<ModPath>,
+    ) -> Self {
+        Self { import_path, item_to_import, original_item, original_path }
+    }
+}
+
 impl ImportAssets {
     pub fn import_candidate(&self) -> &ImportCandidate {
         &self.import_candidate
     }
 
-    fn name_to_import(&self) -> &NameToImport {
-        match &self.import_candidate {
-            ImportCandidate::Path(candidate) => &candidate.name,
-            ImportCandidate::TraitAssocItem(candidate)
-            | ImportCandidate::TraitMethod(candidate) => &candidate.name,
-        }
-    }
-
     pub fn search_for_imports(
         &self,
         sema: &Semantics<RootDatabase>,
         prefix_kind: PrefixKind,
-    ) -> Vec<(hir::ModPath, hir::ItemInNs)> {
+    ) -> Vec<LocatedImport> {
         let _p = profile::span("import_assets::search_for_imports");
         self.search_for(sema, Some(prefix_kind))
     }
 
     /// This may return non-absolute paths if a part of the returned path is already imported into scope.
-    pub fn search_for_relative_paths(
-        &self,
-        sema: &Semantics<RootDatabase>,
-    ) -> Vec<(hir::ModPath, hir::ItemInNs)> {
+    pub fn search_for_relative_paths(&self, sema: &Semantics<RootDatabase>) -> Vec<LocatedImport> {
         let _p = profile::span("import_assets::search_for_relative_paths");
         self.search_for(sema, None)
     }
@@ -166,29 +199,29 @@ impl ImportAssets {
     fn search_for(
         &self,
         sema: &Semantics<RootDatabase>,
-        prefixed: Option<hir::PrefixKind>,
-    ) -> Vec<(hir::ModPath, hir::ItemInNs)> {
-        let current_crate = self.module_with_candidate.krate();
-
-        let unfiltered_imports = match self.name_to_import() {
-            NameToImport::Exact(exact_name) => {
-                imports_locator::find_exact_imports(sema, current_crate, exact_name.clone())
-            }
+        prefixed: Option<PrefixKind>,
+    ) -> Vec<LocatedImport> {
+        let items_with_candidate_name = match self.name_to_import() {
+            NameToImport::Exact(exact_name) => items_locator::with_exact_name(
+                sema,
+                self.module_with_candidate.krate(),
+                exact_name.clone(),
+            ),
             // FIXME: ideally, we should avoid using `fst` for seacrhing trait imports for assoc items:
             // instead, we need to look up all trait impls for a certain struct and search through them only
             // see https://github.com/rust-analyzer/rust-analyzer/pull/7293#issuecomment-761585032
             // and https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0/topic/Blanket.20trait.20impls.20lookup
             // for the details
             NameToImport::Fuzzy(fuzzy_name) => {
-                let (assoc_item_search, limit) = match self.import_candidate {
-                    ImportCandidate::TraitAssocItem(_) | ImportCandidate::TraitMethod(_) => {
-                        (AssocItemSearch::AssocItemsOnly, None)
-                    }
-                    _ => (AssocItemSearch::Exclude, Some(DEFAULT_QUERY_SEARCH_LIMIT)),
+                let (assoc_item_search, limit) = if self.import_candidate.is_trait_candidate() {
+                    (AssocItemSearch::AssocItemsOnly, None)
+                } else {
+                    (AssocItemSearch::Include, Some(DEFAULT_QUERY_SEARCH_LIMIT))
                 };
-                imports_locator::find_similar_imports(
+
+                items_locator::with_similar_name(
                     sema,
-                    current_crate,
+                    self.module_with_candidate.krate(),
                     fuzzy_name.clone(),
                     assoc_item_search,
                     limit,
@@ -196,63 +229,224 @@ impl ImportAssets {
             }
         };
 
-        let db = sema.db;
-        let mut res =
-            applicable_defs(self.import_candidate(), current_crate, db, unfiltered_imports)
-                .filter_map(|candidate| {
-                    let item: hir::ItemInNs = candidate.clone().either(Into::into, Into::into);
-
-                    let item_to_search = match self.import_candidate {
-                        ImportCandidate::TraitAssocItem(_) | ImportCandidate::TraitMethod(_) => {
-                            let canidate_trait = match candidate {
-                                Either::Left(module_def) => {
-                                    module_def.as_assoc_item(db)?.containing_trait(db)
-                                }
-                                _ => None,
-                            }?;
-                            ModuleDef::from(canidate_trait).into()
-                        }
-                        _ => item,
-                    };
-
-                    if let Some(prefix_kind) = prefixed {
-                        self.module_with_candidate.find_use_path_prefixed(
-                            db,
-                            item_to_search,
-                            prefix_kind,
-                        )
-                    } else {
-                        self.module_with_candidate.find_use_path(db, item_to_search)
-                    }
-                    .map(|path| (path, item))
-                })
-                .filter(|(use_path, _)| use_path.len() > 1)
-                .collect::<Vec<_>>();
-        res.sort_by_cached_key(|(path, _)| path.clone());
-        res
+        let scope_definitions = self.scope_definitions(sema);
+        self.applicable_defs(sema.db, prefixed, items_with_candidate_name)
+            .into_iter()
+            .filter(|import| import.import_path.len() > 1)
+            .filter(|import| !scope_definitions.contains(&ScopeDef::from(import.item_to_import)))
+            .sorted_by_key(|import| import.import_path.clone())
+            .collect()
+    }
+
+    fn scope_definitions(&self, sema: &Semantics<RootDatabase>) -> FxHashSet<ScopeDef> {
+        let mut scope_definitions = FxHashSet::default();
+        sema.scope(&self.candidate_node).process_all_names(&mut |_, scope_def| {
+            scope_definitions.insert(scope_def);
+        });
+        scope_definitions
+    }
+
+    fn name_to_import(&self) -> &NameToImport {
+        match &self.import_candidate {
+            ImportCandidate::Path(candidate) => &candidate.name,
+            ImportCandidate::TraitAssocItem(candidate)
+            | ImportCandidate::TraitMethod(candidate) => &candidate.assoc_item_name,
+        }
+    }
+
+    fn applicable_defs(
+        &self,
+        db: &RootDatabase,
+        prefixed: Option<PrefixKind>,
+        items_with_candidate_name: FxHashSet<ItemInNs>,
+    ) -> FxHashSet<LocatedImport> {
+        let _p = profile::span("import_assets::applicable_defs");
+        let current_crate = self.module_with_candidate.krate();
+
+        let mod_path = |item| {
+            get_mod_path(db, item_for_path_search(db, item)?, &self.module_with_candidate, prefixed)
+        };
+
+        match &self.import_candidate {
+            ImportCandidate::Path(path_candidate) => {
+                path_applicable_imports(db, path_candidate, mod_path, items_with_candidate_name)
+            }
+            ImportCandidate::TraitAssocItem(trait_candidate) => trait_applicable_items(
+                db,
+                current_crate,
+                trait_candidate,
+                true,
+                mod_path,
+                items_with_candidate_name,
+            ),
+            ImportCandidate::TraitMethod(trait_candidate) => trait_applicable_items(
+                db,
+                current_crate,
+                trait_candidate,
+                false,
+                mod_path,
+                items_with_candidate_name,
+            ),
+        }
     }
 }
 
-fn applicable_defs<'a>(
-    import_candidate: &ImportCandidate,
-    current_crate: Crate,
+fn path_applicable_imports(
     db: &RootDatabase,
-    unfiltered_imports: Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a>,
-) -> Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a> {
-    let receiver_ty = match import_candidate {
-        ImportCandidate::Path(_) => return unfiltered_imports,
-        ImportCandidate::TraitAssocItem(candidate) | ImportCandidate::TraitMethod(candidate) => {
-            &candidate.receiver_ty
+    path_candidate: &PathImportCandidate,
+    mod_path: impl Fn(ItemInNs) -> Option<ModPath> + Copy,
+    items_with_candidate_name: FxHashSet<ItemInNs>,
+) -> FxHashSet<LocatedImport> {
+    let _p = profile::span("import_assets::path_applicable_imports");
+
+    let (unresolved_first_segment, unresolved_qualifier) = match &path_candidate.qualifier {
+        None => {
+            return items_with_candidate_name
+                .into_iter()
+                .filter_map(|item| {
+                    Some(LocatedImport::new(mod_path(item)?, item, item, mod_path(item)))
+                })
+                .collect();
         }
+        Some(first_segment_unresolved) => (
+            first_segment_unresolved.fist_segment.to_string(),
+            path_to_string_stripping_turbo_fish(&first_segment_unresolved.full_qualifier),
+        ),
     };
 
+    items_with_candidate_name
+        .into_iter()
+        .filter_map(|item| {
+            import_for_item(db, mod_path, &unresolved_first_segment, &unresolved_qualifier, item)
+        })
+        .collect()
+}
+
+fn import_for_item(
+    db: &RootDatabase,
+    mod_path: impl Fn(ItemInNs) -> Option<ModPath>,
+    unresolved_first_segment: &str,
+    unresolved_qualifier: &str,
+    original_item: ItemInNs,
+) -> Option<LocatedImport> {
+    let _p = profile::span("import_assets::import_for_item");
+
+    let original_item_candidate = item_for_path_search(db, original_item)?;
+    let import_path_candidate = mod_path(original_item_candidate)?;
+    let import_path_string = import_path_candidate.to_string();
+
+    let expected_import_end = if item_as_assoc(db, original_item).is_some() {
+        unresolved_qualifier.to_string()
+    } else {
+        format!("{}::{}", unresolved_qualifier, item_name(db, original_item)?)
+    };
+    if !import_path_string.contains(unresolved_first_segment)
+        || !import_path_string.ends_with(&expected_import_end)
+    {
+        return None;
+    }
+
+    let segment_import =
+        find_import_for_segment(db, original_item_candidate, &unresolved_first_segment)?;
+    let trait_item_to_import = item_as_assoc(db, original_item)
+        .and_then(|assoc| assoc.containing_trait(db))
+        .map(|trait_| ItemInNs::from(ModuleDef::from(trait_)));
+    Some(match (segment_import == original_item_candidate, trait_item_to_import) {
+        (true, Some(_)) => {
+            // FIXME we should be able to import both the trait and the segment,
+            // but it's unclear what to do with overlapping edits (merge imports?)
+            // especially in case of lazy completion edit resolutions.
+            return None;
+        }
+        (false, Some(trait_to_import)) => LocatedImport::new(
+            mod_path(trait_to_import)?,
+            trait_to_import,
+            original_item,
+            mod_path(original_item),
+        ),
+        (true, None) => LocatedImport::new(
+            import_path_candidate,
+            original_item_candidate,
+            original_item,
+            mod_path(original_item),
+        ),
+        (false, None) => LocatedImport::new(
+            mod_path(segment_import)?,
+            segment_import,
+            original_item,
+            mod_path(original_item),
+        ),
+    })
+}
+
+fn item_for_path_search(db: &RootDatabase, item: ItemInNs) -> Option<ItemInNs> {
+    Some(match item {
+        ItemInNs::Types(_) | ItemInNs::Values(_) => match item_as_assoc(db, item) {
+            Some(assoc_item) => match assoc_item.container(db) {
+                AssocItemContainer::Trait(trait_) => ItemInNs::from(ModuleDef::from(trait_)),
+                AssocItemContainer::Impl(impl_) => {
+                    ItemInNs::from(ModuleDef::from(impl_.target_ty(db).as_adt()?))
+                }
+            },
+            None => item,
+        },
+        ItemInNs::Macros(_) => item,
+    })
+}
+
+fn find_import_for_segment(
+    db: &RootDatabase,
+    original_item: ItemInNs,
+    unresolved_first_segment: &str,
+) -> Option<ItemInNs> {
+    let segment_is_name = item_name(db, original_item)
+        .map(|name| name.to_string() == unresolved_first_segment)
+        .unwrap_or(false);
+
+    Some(if segment_is_name {
+        original_item
+    } else {
+        let matching_module =
+            module_with_segment_name(db, &unresolved_first_segment, original_item)?;
+        ItemInNs::from(ModuleDef::from(matching_module))
+    })
+}
+
+fn module_with_segment_name(
+    db: &RootDatabase,
+    segment_name: &str,
+    candidate: ItemInNs,
+) -> Option<Module> {
+    let mut current_module = match candidate {
+        ItemInNs::Types(module_def_id) => ModuleDef::from(module_def_id).module(db),
+        ItemInNs::Values(module_def_id) => ModuleDef::from(module_def_id).module(db),
+        ItemInNs::Macros(macro_def_id) => MacroDef::from(macro_def_id).module(db),
+    };
+    while let Some(module) = current_module {
+        if let Some(module_name) = module.name(db) {
+            if module_name.to_string() == segment_name {
+                return Some(module);
+            }
+        }
+        current_module = module.parent(db);
+    }
+    None
+}
+
+fn trait_applicable_items(
+    db: &RootDatabase,
+    current_crate: Crate,
+    trait_candidate: &TraitImportCandidate,
+    trait_assoc_item: bool,
+    mod_path: impl Fn(ItemInNs) -> Option<ModPath>,
+    items_with_candidate_name: FxHashSet<ItemInNs>,
+) -> FxHashSet<LocatedImport> {
+    let _p = profile::span("import_assets::trait_applicable_items");
     let mut required_assoc_items = FxHashSet::default();
 
-    let trait_candidates = unfiltered_imports
-        .filter_map(|input| match input {
-            Either::Left(module_def) => module_def.as_assoc_item(db),
-            _ => None,
-        })
+    let trait_candidates = items_with_candidate_name
+        .into_iter()
+        .filter_map(|input| item_as_assoc(db, input))
         .filter_map(|assoc| {
             let assoc_item_trait = assoc.containing_trait(db)?;
             required_assoc_items.insert(assoc);
@@ -260,11 +454,10 @@ fn applicable_defs<'a>(
         })
         .collect();
 
-    let mut applicable_defs = FxHashSet::default();
+    let mut located_imports = FxHashSet::default();
 
-    match import_candidate {
-        ImportCandidate::Path(_) => unreachable!(),
-        ImportCandidate::TraitAssocItem(_) => receiver_ty.iterate_path_candidates(
+    if trait_assoc_item {
+        trait_candidate.receiver_ty.iterate_path_candidates(
             db,
             current_crate,
             &trait_candidates,
@@ -276,12 +469,21 @@ fn applicable_defs<'a>(
                             return None;
                         }
                     }
-                    applicable_defs.insert(Either::Left(assoc_to_module_def(assoc)));
+
+                    let item = ItemInNs::from(ModuleDef::from(assoc.containing_trait(db)?));
+                    let original_item = assoc_to_item(assoc);
+                    located_imports.insert(LocatedImport::new(
+                        mod_path(item)?,
+                        item,
+                        original_item,
+                        mod_path(original_item),
+                    ));
                 }
                 None::<()>
             },
-        ),
-        ImportCandidate::TraitMethod(_) => receiver_ty.iterate_method_candidates(
+        )
+    } else {
+        trait_candidate.receiver_ty.iterate_method_candidates(
             db,
             current_crate,
             &trait_candidates,
@@ -289,21 +491,41 @@ fn applicable_defs<'a>(
             |_, function| {
                 let assoc = function.as_assoc_item(db)?;
                 if required_assoc_items.contains(&assoc) {
-                    applicable_defs.insert(Either::Left(assoc_to_module_def(assoc)));
+                    let item = ItemInNs::from(ModuleDef::from(assoc.containing_trait(db)?));
+                    let original_item = assoc_to_item(assoc);
+                    located_imports.insert(LocatedImport::new(
+                        mod_path(item)?,
+                        item,
+                        original_item,
+                        mod_path(original_item),
+                    ));
                 }
                 None::<()>
             },
-        ),
+        )
     };
 
-    Box::new(applicable_defs.into_iter())
+    located_imports
 }
 
-fn assoc_to_module_def(assoc: AssocItem) -> ModuleDef {
+fn assoc_to_item(assoc: AssocItem) -> ItemInNs {
     match assoc {
-        AssocItem::Function(f) => f.into(),
-        AssocItem::Const(c) => c.into(),
-        AssocItem::TypeAlias(t) => t.into(),
+        AssocItem::Function(f) => ItemInNs::from(ModuleDef::from(f)),
+        AssocItem::Const(c) => ItemInNs::from(ModuleDef::from(c)),
+        AssocItem::TypeAlias(t) => ItemInNs::from(ModuleDef::from(t)),
+    }
+}
+
+fn get_mod_path(
+    db: &RootDatabase,
+    item_to_search: ItemInNs,
+    module_with_candidate: &Module,
+    prefixed: Option<PrefixKind>,
+) -> Option<ModPath> {
+    if let Some(prefix_kind) = prefixed {
+        module_with_candidate.find_use_path_prefixed(db, item_to_search, prefix_kind)
+    } else {
+        module_with_candidate.find_use_path(db, item_to_search)
     }
 }
 
@@ -316,7 +538,7 @@ impl ImportCandidate {
             Some(_) => None,
             None => Some(Self::TraitMethod(TraitImportCandidate {
                 receiver_ty: sema.type_of_expr(&method_call.receiver()?)?,
-                name: NameToImport::Exact(method_call.name_ref()?.to_string()),
+                assoc_item_name: NameToImport::Exact(method_call.name_ref()?.to_string()),
             })),
         }
     }
@@ -325,41 +547,63 @@ impl ImportCandidate {
         if sema.resolve_path(path).is_some() {
             return None;
         }
+        path_import_candidate(
+            sema,
+            path.qualifier(),
+            NameToImport::Exact(path.segment()?.name_ref()?.to_string()),
+        )
+    }
 
-        let segment = path.segment()?;
-        let candidate = if let Some(qualifier) = path.qualifier() {
-            let qualifier_start = qualifier.syntax().descendants().find_map(ast::NameRef::cast)?;
-            let qualifier_start_path =
-                qualifier_start.syntax().ancestors().find_map(ast::Path::cast)?;
-            if let Some(qualifier_start_resolution) = sema.resolve_path(&qualifier_start_path) {
-                let qualifier_resolution = if qualifier_start_path == qualifier {
-                    qualifier_start_resolution
+    fn for_fuzzy_path(
+        qualifier: Option<ast::Path>,
+        fuzzy_name: String,
+        sema: &Semantics<RootDatabase>,
+    ) -> Option<Self> {
+        path_import_candidate(sema, qualifier, NameToImport::Fuzzy(fuzzy_name))
+    }
+
+    fn is_trait_candidate(&self) -> bool {
+        matches!(self, ImportCandidate::TraitAssocItem(_) | ImportCandidate::TraitMethod(_))
+    }
+}
+
+fn path_import_candidate(
+    sema: &Semantics<RootDatabase>,
+    qualifier: Option<ast::Path>,
+    name: NameToImport,
+) -> Option<ImportCandidate> {
+    Some(match qualifier {
+        Some(qualifier) => match sema.resolve_path(&qualifier) {
+            None => {
+                let qualifier_start =
+                    qualifier.syntax().descendants().find_map(ast::NameRef::cast)?;
+                let qualifier_start_path =
+                    qualifier_start.syntax().ancestors().find_map(ast::Path::cast)?;
+                if sema.resolve_path(&qualifier_start_path).is_none() {
+                    ImportCandidate::Path(PathImportCandidate {
+                        qualifier: Some(FirstSegmentUnresolved {
+                            fist_segment: qualifier_start,
+                            full_qualifier: qualifier,
+                        }),
+                        name,
+                    })
                 } else {
-                    sema.resolve_path(&qualifier)?
-                };
-                match qualifier_resolution {
-                    hir::PathResolution::Def(hir::ModuleDef::Adt(assoc_item_path)) => {
-                        ImportCandidate::TraitAssocItem(TraitImportCandidate {
-                            receiver_ty: assoc_item_path.ty(sema.db),
-                            name: NameToImport::Exact(segment.name_ref()?.to_string()),
-                        })
-                    }
-                    _ => return None,
+                    return None;
                 }
-            } else {
-                ImportCandidate::Path(PathImportCandidate {
-                    qualifier: Some(qualifier),
-                    name: NameToImport::Exact(qualifier_start.to_string()),
+            }
+            Some(PathResolution::Def(ModuleDef::Adt(assoc_item_path))) => {
+                ImportCandidate::TraitAssocItem(TraitImportCandidate {
+                    receiver_ty: assoc_item_path.ty(sema.db),
+                    assoc_item_name: name,
                 })
             }
-        } else {
-            ImportCandidate::Path(PathImportCandidate {
-                qualifier: None,
-                name: NameToImport::Exact(
-                    segment.syntax().descendants().find_map(ast::NameRef::cast)?.to_string(),
-                ),
-            })
-        };
-        Some(candidate)
-    }
+            Some(_) => return None,
+        },
+        None => ImportCandidate::Path(PathImportCandidate { qualifier: None, name }),
+    })
+}
+
+fn item_as_assoc(db: &RootDatabase, item: ItemInNs) -> Option<AssocItem> {
+    item.as_module_def_id()
+        .and_then(|module_def_id| ModuleDef::from(module_def_id).as_assoc_item(db))
 }
diff --git a/crates/ide_db/src/helpers/insert_use.rs b/crates/ide_db/src/helpers/insert_use.rs
index fd4035198..df66d8ea0 100644
--- a/crates/ide_db/src/helpers/insert_use.rs
+++ b/crates/ide_db/src/helpers/insert_use.rs
@@ -13,12 +13,12 @@ use syntax::{
     },
     AstToken, InsertPosition, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxToken,
 };
-use test_utils::mark;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct InsertUseConfig {
     pub merge: Option<MergeBehavior>,
     pub prefix_kind: hir::PrefixKind,
+    pub group: bool,
 }
 
 #[derive(Debug, Clone)]
@@ -99,13 +99,13 @@ fn is_inner_comment(token: SyntaxToken) -> bool {
 pub fn insert_use<'a>(
     scope: &ImportScope,
     path: ast::Path,
-    merge: Option<MergeBehavior>,
+    cfg: InsertUseConfig,
 ) -> SyntaxRewriter<'a> {
     let _p = profile::span("insert_use");
     let mut rewriter = SyntaxRewriter::default();
     let use_item = make::use_(None, make::use_tree(path.clone(), None, None, false));
     // merge into existing imports if possible
-    if let Some(mb) = merge {
+    if let Some(mb) = cfg.merge {
         for existing_use in scope.as_syntax_node().children().filter_map(ast::Use::cast) {
             if let Some(merged) = try_merge_imports(&existing_use, &use_item, mb) {
                 rewriter.replace(existing_use.syntax(), merged.syntax());
@@ -116,7 +116,7 @@ pub fn insert_use<'a>(
 
     // either we weren't allowed to merge or there is no import that fits the merge conditions
     // so look for the place we have to insert to
-    let (insert_position, add_blank) = find_insert_position(scope, path);
+    let (insert_position, add_blank) = find_insert_position(scope, path, cfg.group);
 
     let indent = if let ident_level @ 1..=usize::MAX = scope.indent_level().0 as usize {
         Some(make::tokens::whitespace(&" ".repeat(4 * ident_level)).into())
@@ -137,7 +137,7 @@ pub fn insert_use<'a>(
 
         if add_blank.has_before() {
             if let Some(indent) = indent.clone() {
-                mark::hit!(insert_use_indent_before);
+                cov_mark::hit!(insert_use_indent_before);
                 buf.push(indent);
             }
         }
@@ -155,11 +155,11 @@ pub fn insert_use<'a>(
         // only add indentation *after* our stuff if there's another node directly after it
         if add_blank.has_after() && matches!(insert_position, InsertPosition::Before(_)) {
             if let Some(indent) = indent {
-                mark::hit!(insert_use_indent_after);
+                cov_mark::hit!(insert_use_indent_after);
                 buf.push(indent);
             }
         } else if add_blank.has_after() && matches!(insert_position, InsertPosition::After(_)) {
-            mark::hit!(insert_use_no_indent_after);
+            cov_mark::hit!(insert_use_no_indent_after);
         }
 
         buf
@@ -538,6 +538,7 @@ impl AddBlankLine {
 fn find_insert_position(
     scope: &ImportScope,
     insert_path: ast::Path,
+    group_imports: bool,
 ) -> (InsertPosition<SyntaxElement>, AddBlankLine) {
     let group = ImportGroup::new(&insert_path);
     let path_node_iter = scope
@@ -550,6 +551,14 @@ fn find_insert_position(
             let has_tl = tree.use_tree_list().is_some();
             Some((path, has_tl, node))
         });
+
+    if !group_imports {
+        if let Some((_, _, node)) = path_node_iter.last() {
+            return (InsertPosition::After(node.into()), AddBlankLine::Before);
+        }
+        return (InsertPosition::First, AddBlankLine::AfterTwice);
+    }
+
     // Iterator that discards anything thats not in the required grouping
     // This implementation allows the user to rearrange their import groups as this only takes the first group that fits
     let group_iter = path_node_iter
@@ -565,6 +574,7 @@ fn find_insert_position(
             use_tree_path_cmp(&insert_path, false, path, has_tl) != Ordering::Greater
         },
     );
+
     match post_insert {
         // insert our import before that element
         Some((.., node)) => (InsertPosition::Before(node.into()), AddBlankLine::After),
diff --git a/crates/ide_db/src/helpers/insert_use/tests.rs b/crates/ide_db/src/helpers/insert_use/tests.rs
index 4bbe66f1f..3d151e629 100644
--- a/crates/ide_db/src/helpers/insert_use/tests.rs
+++ b/crates/ide_db/src/helpers/insert_use/tests.rs
@@ -1,8 +1,32 @@
 use super::*;
 
+use hir::PrefixKind;
 use test_utils::assert_eq_text;
 
 #[test]
+fn insert_not_group() {
+    check(
+        "use external_crate2::bar::A",
+        r"
+use std::bar::B;
+use external_crate::bar::A;
+use crate::bar::A;
+use self::bar::A;
+use super::bar::A;",
+        r"
+use std::bar::B;
+use external_crate::bar::A;
+use crate::bar::A;
+use self::bar::A;
+use super::bar::A;
+use external_crate2::bar::A;",
+        None,
+        false,
+        false,
+    );
+}
+
+#[test]
 fn insert_existing() {
     check_full("std::fs", "use std::fs;", "use std::fs;")
 }
@@ -27,7 +51,7 @@ use std::bar::G;",
 
 #[test]
 fn insert_start_indent() {
-    mark::check!(insert_use_indent_after);
+    cov_mark::check!(insert_use_indent_after);
     check_none(
         "std::bar::AA",
         r"
@@ -96,7 +120,7 @@ use std::bar::ZZ;",
 
 #[test]
 fn insert_end_indent() {
-    mark::check!(insert_use_indent_before);
+    cov_mark::check!(insert_use_indent_before);
     check_none(
         "std::bar::ZZ",
         r"
@@ -231,7 +255,7 @@ fn insert_empty_file() {
 
 #[test]
 fn insert_empty_module() {
-    mark::check!(insert_use_no_indent_after);
+    cov_mark::check!(insert_use_no_indent_after);
     check(
         "foo::bar",
         "mod x {}",
@@ -240,6 +264,7 @@ fn insert_empty_module() {
 }",
         None,
         true,
+        true,
     )
 }
 
@@ -584,6 +609,7 @@ fn check(
     ra_fixture_after: &str,
     mb: Option<MergeBehavior>,
     module: bool,
+    group: bool,
 ) {
     let mut syntax = ast::SourceFile::parse(ra_fixture_before).tree().syntax().clone();
     if module {
@@ -597,21 +623,25 @@ fn check(
         .find_map(ast::Path::cast)
         .unwrap();
 
-    let rewriter = insert_use(&file, path, mb);
+    let rewriter = insert_use(
+        &file,
+        path,
+        InsertUseConfig { merge: mb, prefix_kind: PrefixKind::Plain, group },
+    );
     let result = rewriter.rewrite(file.as_syntax_node()).to_string();
     assert_eq_text!(ra_fixture_after, &result);
 }
 
 fn check_full(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Full), false)
+    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Full), false, true)
 }
 
 fn check_last(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Last), false)
+    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Last), false, true)
 }
 
 fn check_none(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, None, false)
+    check(path, ra_fixture_before, ra_fixture_after, None, false, true)
 }
 
 fn check_merge_only_fail(ra_fixture0: &str, ra_fixture1: &str, mb: MergeBehavior) {
diff --git a/crates/ide_db/src/imports_locator.rs b/crates/ide_db/src/items_locator.rs
index 502e8281a..8a7f02935 100644
--- a/crates/ide_db/src/imports_locator.rs
+++ b/crates/ide_db/src/items_locator.rs
@@ -1,9 +1,10 @@
 //! This module contains an import search functionality that is provided to the assists module.
 //! Later, this should be moved away to a separate crate that is accessible from the assists module.
 
+use either::Either;
 use hir::{
     import_map::{self, ImportKind},
-    AsAssocItem, Crate, MacroDef, ModuleDef, Semantics,
+    AsAssocItem, Crate, ItemInNs, ModuleDef, Semantics,
 };
 use syntax::{ast, AstNode, SyntaxKind::NAME};
 
@@ -12,47 +13,47 @@ use crate::{
     symbol_index::{self, FileSymbol},
     RootDatabase,
 };
-use either::Either;
 use rustc_hash::FxHashSet;
 
 pub(crate) const DEFAULT_QUERY_SEARCH_LIMIT: usize = 40;
 
-pub fn find_exact_imports<'a>(
-    sema: &Semantics<'a, RootDatabase>,
+pub fn with_exact_name(
+    sema: &Semantics<'_, RootDatabase>,
     krate: Crate,
-    name_to_import: String,
-) -> Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>>> {
+    exact_name: String,
+) -> FxHashSet<ItemInNs> {
     let _p = profile::span("find_exact_imports");
-    Box::new(find_imports(
+    find_items(
         sema,
         krate,
         {
-            let mut local_query = symbol_index::Query::new(name_to_import.clone());
+            let mut local_query = symbol_index::Query::new(exact_name.clone());
             local_query.exact();
             local_query.limit(DEFAULT_QUERY_SEARCH_LIMIT);
             local_query
         },
-        import_map::Query::new(name_to_import)
+        import_map::Query::new(exact_name)
             .limit(DEFAULT_QUERY_SEARCH_LIMIT)
             .name_only()
             .search_mode(import_map::SearchMode::Equals)
             .case_sensitive(),
-    ))
+    )
 }
 
+#[derive(Debug)]
 pub enum AssocItemSearch {
     Include,
     Exclude,
     AssocItemsOnly,
 }
 
-pub fn find_similar_imports<'a>(
-    sema: &Semantics<'a, RootDatabase>,
+pub fn with_similar_name(
+    sema: &Semantics<'_, RootDatabase>,
     krate: Crate,
     fuzzy_search_string: String,
     assoc_item_search: AssocItemSearch,
     limit: Option<usize>,
-) -> Box<dyn Iterator<Item = Either<ModuleDef, MacroDef>> + 'a> {
+) -> FxHashSet<ItemInNs> {
     let _p = profile::span("find_similar_imports");
 
     let mut external_query = import_map::Query::new(fuzzy_search_string.clone())
@@ -76,37 +77,39 @@ pub fn find_similar_imports<'a>(
         local_query.limit(limit);
     }
 
-    let db = sema.db;
-    Box::new(find_imports(sema, krate, local_query, external_query).filter(
-        move |import_candidate| match assoc_item_search {
+    find_items(sema, krate, local_query, external_query)
+        .into_iter()
+        .filter(move |&item| match assoc_item_search {
             AssocItemSearch::Include => true,
-            AssocItemSearch::Exclude => !is_assoc_item(import_candidate, db),
-            AssocItemSearch::AssocItemsOnly => is_assoc_item(import_candidate, db),
-        },
-    ))
+            AssocItemSearch::Exclude => !is_assoc_item(item, sema.db),
+            AssocItemSearch::AssocItemsOnly => is_assoc_item(item, sema.db),
+        })
+        .collect()
 }
 
-fn is_assoc_item(import_candidate: &Either<ModuleDef, MacroDef>, db: &RootDatabase) -> bool {
-    match import_candidate {
-        Either::Left(ModuleDef::Function(function)) => function.as_assoc_item(db).is_some(),
-        Either::Left(ModuleDef::Const(const_)) => const_.as_assoc_item(db).is_some(),
-        Either::Left(ModuleDef::TypeAlias(type_alias)) => type_alias.as_assoc_item(db).is_some(),
-        _ => false,
-    }
+fn is_assoc_item(item: ItemInNs, db: &RootDatabase) -> bool {
+    item.as_module_def_id()
+        .and_then(|module_def_id| ModuleDef::from(module_def_id).as_assoc_item(db))
+        .is_some()
 }
 
-fn find_imports<'a>(
-    sema: &Semantics<'a, RootDatabase>,
+fn find_items(
+    sema: &Semantics<'_, RootDatabase>,
     krate: Crate,
     local_query: symbol_index::Query,
     external_query: import_map::Query,
-) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+) -> FxHashSet<ItemInNs> {
     let _p = profile::span("find_similar_imports");
     let db = sema.db;
 
     // Query dependencies first.
-    let mut candidates: FxHashSet<_> =
-        krate.query_external_importables(db, external_query).collect();
+    let mut candidates = krate
+        .query_external_importables(db, external_query)
+        .map(|external_importable| match external_importable {
+            Either::Left(module_def) => ItemInNs::from(module_def),
+            Either::Right(macro_def) => ItemInNs::from(macro_def),
+        })
+        .collect::<FxHashSet<_>>();
 
     // Query the local crate using the symbol index.
     let local_results = symbol_index::crate_symbols(db, krate.into(), local_query);
@@ -114,19 +117,19 @@ fn find_imports<'a>(
     candidates.extend(
         local_results
             .into_iter()
-            .filter_map(|import_candidate| get_name_definition(sema, &import_candidate))
+            .filter_map(|local_candidate| get_name_definition(sema, &local_candidate))
             .filter_map(|name_definition_to_import| match name_definition_to_import {
-                Definition::ModuleDef(module_def) => Some(Either::Left(module_def)),
-                Definition::Macro(macro_def) => Some(Either::Right(macro_def)),
+                Definition::ModuleDef(module_def) => Some(ItemInNs::from(module_def)),
+                Definition::Macro(macro_def) => Some(ItemInNs::from(macro_def)),
                 _ => None,
             }),
     );
 
-    candidates.into_iter()
+    candidates
 }
 
-fn get_name_definition<'a>(
-    sema: &Semantics<'a, RootDatabase>,
+fn get_name_definition(
+    sema: &Semantics<'_, RootDatabase>,
     import_candidate: &FileSymbol,
 ) -> Option<Definition> {
     let _p = profile::span("get_name_definition");
diff --git a/crates/ide_db/src/lib.rs b/crates/ide_db/src/lib.rs
index 6eb34b06b..88ee4a87d 100644
--- a/crates/ide_db/src/lib.rs
+++ b/crates/ide_db/src/lib.rs
@@ -8,7 +8,7 @@ pub mod line_index;
 pub mod symbol_index;
 pub mod defs;
 pub mod search;
-pub mod imports_locator;
+pub mod items_locator;
 pub mod source_change;
 pub mod ty_filter;
 pub mod traits;
diff --git a/crates/ide_ssr/Cargo.toml b/crates/ide_ssr/Cargo.toml
index edbc1846b..8c31df13a 100644
--- a/crates/ide_ssr/Cargo.toml
+++ b/crates/ide_ssr/Cargo.toml
@@ -11,6 +11,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 rustc-hash = "1.1.0"
 itertools = "0.10.0"
 
@@ -18,7 +19,7 @@ text_edit = { path = "../text_edit", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 ide_db = { path = "../ide_db", version = "0.0.0" }
 hir = { path = "../hir", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/ide_ssr/src/from_comment.rs b/crates/ide_ssr/src/from_comment.rs
new file mode 100644
index 000000000..f1b312284
--- /dev/null
+++ b/crates/ide_ssr/src/from_comment.rs
@@ -0,0 +1,32 @@
+//! This module allows building an SSR MatchFinder by parsing the SSR rule
+//! from a comment.
+
+use ide_db::{
+    base_db::{FilePosition, FileRange, SourceDatabase},
+    RootDatabase,
+};
+use syntax::{
+    ast::{self, AstNode, AstToken},
+    TextRange,
+};
+
+use crate::MatchFinder;
+
+/// Attempts to build an SSR MatchFinder from a comment at the given file
+/// range. If successful, returns the MatchFinder and a TextRange covering
+/// comment.
+pub fn ssr_from_comment(db: &RootDatabase, frange: FileRange) -> Option<(MatchFinder, TextRange)> {
+    let comment = {
+        let file = db.parse(frange.file_id);
+        file.tree().syntax().token_at_offset(frange.range.start()).find_map(ast::Comment::cast)
+    }?;
+    let comment_text_without_prefix = comment.text().strip_prefix(comment.prefix()).unwrap();
+    let ssr_rule = comment_text_without_prefix.parse().ok()?;
+
+    let lookup_context = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
+
+    let mut match_finder = MatchFinder::in_context(db, lookup_context, vec![]);
+    match_finder.add_rule(ssr_rule).ok()?;
+
+    Some((match_finder, comment.syntax().text_range()))
+}
diff --git a/crates/ide_ssr/src/lib.rs b/crates/ide_ssr/src/lib.rs
index a97fc8bca..00585f448 100644
--- a/crates/ide_ssr/src/lib.rs
+++ b/crates/ide_ssr/src/lib.rs
@@ -57,7 +57,17 @@
 //
 // | VS Code | **Rust Analyzer: Structural Search Replace**
 // |===
+//
+// Also available as an assist, by writing a comment containing the structural
+// search and replace rule. You will only see the assist if the comment can
+// be parsed as a valid structural search and replace rule.
+//
+// ```rust
+// // Place the cursor on the line below to see the assist 💡.
+// // foo($a, $b) ==>> ($a).foo($b)
+// ```
 
+mod from_comment;
 mod matching;
 mod nester;
 mod parsing;
@@ -71,6 +81,7 @@ mod tests;
 
 use crate::errors::bail;
 pub use crate::errors::SsrError;
+pub use crate::from_comment::ssr_from_comment;
 pub use crate::matching::Match;
 use crate::matching::MatchFailureReason;
 use hir::Semantics;
diff --git a/crates/ide_ssr/src/matching.rs b/crates/ide_ssr/src/matching.rs
index df013bae9..e1adb381e 100644
--- a/crates/ide_ssr/src/matching.rs
+++ b/crates/ide_ssr/src/matching.rs
@@ -15,7 +15,6 @@ use syntax::{
     ast::{AstNode, AstToken},
     SmolStr,
 };
-use test_utils::mark;
 
 // Creates a match error. If we're currently attempting to match some code that we thought we were
 // going to match, as indicated by the --debug-snippet flag, then populate the reason field.
@@ -731,7 +730,7 @@ impl NodeKind {
     fn matches(&self, node: &SyntaxNode) -> Result<(), MatchFailed> {
         let ok = match self {
             Self::Literal => {
-                mark::hit!(literal_constraint);
+                cov_mark::hit!(literal_constraint);
                 ast::Literal::can_cast(node.kind())
             }
         };
diff --git a/crates/ide_ssr/src/parsing.rs b/crates/ide_ssr/src/parsing.rs
index 3d5e4feb7..5ff25cb6d 100644
--- a/crates/ide_ssr/src/parsing.rs
+++ b/crates/ide_ssr/src/parsing.rs
@@ -10,7 +10,6 @@ use crate::{SsrError, SsrPattern, SsrRule};
 use rustc_hash::{FxHashMap, FxHashSet};
 use std::{fmt::Display, str::FromStr};
 use syntax::{ast, AstNode, SmolStr, SyntaxKind, SyntaxNode, T};
-use test_utils::mark;
 
 #[derive(Debug)]
 pub(crate) struct ParsedRule {
@@ -131,7 +130,7 @@ impl RuleBuilder {
             let old_len = self.rules.len();
             self.rules.retain(|rule| contains_path(&rule.pattern));
             if self.rules.len() < old_len {
-                mark::hit!(pattern_is_a_single_segment_path);
+                cov_mark::hit!(pattern_is_a_single_segment_path);
             }
         }
         Ok(self.rules)
diff --git a/crates/ide_ssr/src/replacing.rs b/crates/ide_ssr/src/replacing.rs
index 06a94a46c..c9ccc1961 100644
--- a/crates/ide_ssr/src/replacing.rs
+++ b/crates/ide_ssr/src/replacing.rs
@@ -5,7 +5,7 @@ use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet};
 use syntax::ast::{self, AstNode, AstToken};
 use syntax::{SyntaxElement, SyntaxKind, SyntaxNode, SyntaxToken, TextRange, TextSize};
-use test_utils::mark;
+
 use text_edit::TextEdit;
 
 /// Returns a text edit that will replace each match in `matches` with its corresponding replacement
@@ -128,7 +128,7 @@ impl ReplacementRenderer<'_> {
                     && (placeholder_value.autoderef_count > 0
                         || placeholder_value.autoref_kind != ast::SelfParamKind::Owned)
                 {
-                    mark::hit!(replace_autoref_autoderef_capture);
+                    cov_mark::hit!(replace_autoref_autoderef_capture);
                     let ref_kind = match placeholder_value.autoref_kind {
                         ast::SelfParamKind::Owned => "",
                         ast::SelfParamKind::Ref => "&",
diff --git a/crates/ide_ssr/src/resolving.rs b/crates/ide_ssr/src/resolving.rs
index 14e5a3b69..af94c7bb1 100644
--- a/crates/ide_ssr/src/resolving.rs
+++ b/crates/ide_ssr/src/resolving.rs
@@ -6,7 +6,6 @@ use ide_db::base_db::FilePosition;
 use parsing::Placeholder;
 use rustc_hash::FxHashMap;
 use syntax::{ast, SmolStr, SyntaxKind, SyntaxNode, SyntaxToken};
-use test_utils::mark;
 
 pub(crate) struct ResolutionScope<'db> {
     scope: hir::SemanticsScope<'db>,
@@ -170,13 +169,13 @@ impl Resolver<'_, '_> {
                     // calls. e.g. `Foo::bar($s)` should match `x.bar()`.
                     true
                 } else {
-                    mark::hit!(replace_associated_trait_default_function_call);
+                    cov_mark::hit!(replace_associated_trait_default_function_call);
                     false
                 }
             }
             hir::PathResolution::AssocItem(_) => {
                 // Not a function. Could be a constant or an associated type.
-                mark::hit!(replace_associated_trait_constant);
+                cov_mark::hit!(replace_associated_trait_constant);
                 false
             }
             _ => true,
@@ -267,7 +266,7 @@ fn pick_node_for_resolution(node: SyntaxNode) -> SyntaxNode {
     match node.kind() {
         SyntaxKind::EXPR_STMT => {
             if let Some(n) = node.first_child() {
-                mark::hit!(cursor_after_semicolon);
+                cov_mark::hit!(cursor_after_semicolon);
                 return n;
             }
         }
@@ -291,7 +290,7 @@ fn path_contains_type_arguments(path: Option<ast::Path>) -> bool {
     if let Some(path) = path {
         if let Some(segment) = path.segment() {
             if segment.generic_arg_list().is_some() {
-                mark::hit!(type_arguments_within_path);
+                cov_mark::hit!(type_arguments_within_path);
                 return true;
             }
         }
diff --git a/crates/ide_ssr/src/search.rs b/crates/ide_ssr/src/search.rs
index 836eb94b2..28cef742c 100644
--- a/crates/ide_ssr/src/search.rs
+++ b/crates/ide_ssr/src/search.rs
@@ -12,7 +12,6 @@ use ide_db::{
 };
 use rustc_hash::FxHashSet;
 use syntax::{ast, AstNode, SyntaxKind, SyntaxNode};
-use test_utils::mark;
 
 /// A cache for the results of find_usages. This is for when we have multiple patterns that have the
 /// same path. e.g. if the pattern was `foo::Bar` that can parse as a path, an expression, a type
@@ -61,7 +60,7 @@ impl<'db> MatchFinder<'db> {
             for file_range in self.find_usages(usage_cache, definition).file_ranges() {
                 if let Some(node_to_match) = self.find_node_to_match(resolved_path, file_range) {
                     if !is_search_permitted_ancestors(&node_to_match) {
-                        mark::hit!(use_declaration_with_braces);
+                        cov_mark::hit!(use_declaration_with_braces);
                         continue;
                     }
                     self.try_add_match(rule, &node_to_match, &None, matches_out);
@@ -205,7 +204,7 @@ impl<'db> MatchFinder<'db> {
         matches_out: &mut Vec<Match>,
     ) {
         if !self.within_range_restrictions(code) {
-            mark::hit!(replace_nonpath_within_selection);
+            cov_mark::hit!(replace_nonpath_within_selection);
             return;
         }
         if let Ok(m) = matching::get_match(false, rule, code, restrict_range, &self.sema) {
diff --git a/crates/ide_ssr/src/tests.rs b/crates/ide_ssr/src/tests.rs
index a3ea44f23..1d8565dc0 100644
--- a/crates/ide_ssr/src/tests.rs
+++ b/crates/ide_ssr/src/tests.rs
@@ -3,7 +3,7 @@ use expect_test::{expect, Expect};
 use ide_db::base_db::{salsa::Durability, FileId, FilePosition, FileRange, SourceDatabaseExt};
 use rustc_hash::FxHashSet;
 use std::sync::Arc;
-use test_utils::{mark, RangeOrOffset};
+use test_utils::RangeOrOffset;
 
 fn parse_error_text(query: &str) -> String {
     format!("{}", query.parse::<SsrRule>().unwrap_err())
@@ -492,7 +492,7 @@ fn match_resolved_type_name() {
 
 #[test]
 fn type_arguments_within_path() {
-    mark::check!(type_arguments_within_path);
+    cov_mark::check!(type_arguments_within_path);
     let code = r#"
         mod foo {
             pub struct Bar<T> {t: T}
@@ -508,7 +508,7 @@ fn type_arguments_within_path() {
 
 #[test]
 fn literal_constraint() {
-    mark::check!(literal_constraint);
+    cov_mark::check!(literal_constraint);
     let code = r#"
         enum Option<T> { Some(T), None }
         use Option::Some;
@@ -641,7 +641,7 @@ fn replace_associated_function_call() {
 
 #[test]
 fn replace_associated_trait_default_function_call() {
-    mark::check!(replace_associated_trait_default_function_call);
+    cov_mark::check!(replace_associated_trait_default_function_call);
     assert_ssr_transform(
         "Bar2::foo() ==>> Bar2::foo2()",
         r#"
@@ -673,7 +673,7 @@ fn replace_associated_trait_default_function_call() {
 
 #[test]
 fn replace_associated_trait_constant() {
-    mark::check!(replace_associated_trait_constant);
+    cov_mark::check!(replace_associated_trait_constant);
     assert_ssr_transform(
         "Bar2::VALUE ==>> Bar2::VALUE_2222",
         r#"
@@ -998,7 +998,7 @@ fn use_declaration_with_braces() {
     // It would be OK for a path rule to match and alter a use declaration. We shouldn't mess it up
     // though. In particular, we must not change `use foo::{baz, bar}` to `use foo::{baz,
     // foo2::bar2}`.
-    mark::check!(use_declaration_with_braces);
+    cov_mark::check!(use_declaration_with_braces);
     assert_ssr_transform(
         "foo::bar ==>> foo2::bar2",
         r#"
@@ -1076,7 +1076,7 @@ fn ufcs_matches_method_call() {
 
 #[test]
 fn pattern_is_a_single_segment_path() {
-    mark::check!(pattern_is_a_single_segment_path);
+    cov_mark::check!(pattern_is_a_single_segment_path);
     // The first function should not be altered because the `foo` in scope at the cursor position is
     // a different `foo`. This case is special because "foo" can be parsed as a pattern (IDENT_PAT ->
     // NAME -> IDENT), which contains no path. If we're not careful we'll end up matching the `foo`
@@ -1118,7 +1118,7 @@ fn replace_local_variable_reference() {
     // The pattern references a local variable `foo` in the block containing the cursor. We should
     // only replace references to this variable `foo`, not other variables that just happen to have
     // the same name.
-    mark::check!(cursor_after_semicolon);
+    cov_mark::check!(cursor_after_semicolon);
     assert_ssr_transform(
         "foo + $a ==>> $a - foo",
         r#"
@@ -1179,7 +1179,7 @@ fn replace_path_within_selection() {
 
 #[test]
 fn replace_nonpath_within_selection() {
-    mark::check!(replace_nonpath_within_selection);
+    cov_mark::check!(replace_nonpath_within_selection);
     assert_ssr_transform(
         "$a + $b ==>> $b * $a",
         r#"
@@ -1269,7 +1269,7 @@ fn replace_autoref_autoderef_capture() {
     // second, we already have a reference, so it isn't. When $a is used in a context where autoref
     // doesn't apply, we need to prefix it with `&`. Finally, we have some cases where autoderef
     // needs to be applied.
-    mark::check!(replace_autoref_autoderef_capture);
+    cov_mark::check!(replace_autoref_autoderef_capture);
     let code = r#"
         struct Foo {}
         impl Foo {
diff --git a/crates/mbe/Cargo.toml b/crates/mbe/Cargo.toml
index bb2656a80..139214207 100644
--- a/crates/mbe/Cargo.toml
+++ b/crates/mbe/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 rustc-hash = "1.1.0"
 smallvec = "1.2.0"
 log = "0.4.8"
@@ -17,8 +18,8 @@ log = "0.4.8"
 syntax = { path = "../syntax", version = "0.0.0" }
 parser = { path = "../parser", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 stdx = { path = "../stdx", version = "0.0.0" }
 
 [dev-dependencies]
 profile = { path = "../profile" }
+test_utils = { path = "../test_utils" }
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs
index f3d2da55a..33b85e23d 100644
--- a/crates/mbe/src/lib.rs
+++ b/crates/mbe/src/lib.rs
@@ -17,7 +17,6 @@ mod benchmark;
 
 use std::fmt;
 
-use test_utils::mark;
 pub use tt::{Delimiter, DelimiterKind, Punct};
 
 use crate::{
@@ -217,7 +216,7 @@ impl MacroDef {
         let mut rules = Vec::new();
 
         if Some(tt::DelimiterKind::Brace) == tt.delimiter_kind() {
-            mark::hit!(parse_macro_def_rules);
+            cov_mark::hit!(parse_macro_def_rules);
             while src.len() > 0 {
                 let rule = Rule::parse(&mut src, true)?;
                 rules.push(rule);
@@ -229,7 +228,7 @@ impl MacroDef {
                 }
             }
         } else {
-            mark::hit!(parse_macro_def_simple);
+            cov_mark::hit!(parse_macro_def_simple);
             let rule = Rule::parse(&mut src, false)?;
             if src.len() != 0 {
                 return Err(ParseError::Expected("remain tokens in macro def".to_string()));
diff --git a/crates/mbe/src/tests.rs b/crates/mbe/src/tests.rs
index 08acd4ac2..3a168bb4b 100644
--- a/crates/mbe/src/tests.rs
+++ b/crates/mbe/src/tests.rs
@@ -6,7 +6,7 @@ use syntax::{
     SyntaxKind::{ERROR, IDENT},
     SyntaxNode, WalkEvent, T,
 };
-use test_utils::{assert_eq_text, mark};
+use test_utils::assert_eq_text;
 
 use super::*;
 
@@ -687,7 +687,7 @@ fn test_match_literal() {
 
 #[test]
 fn test_parse_macro_def_simple() {
-    mark::check!(parse_macro_def_simple);
+    cov_mark::check!(parse_macro_def_simple);
 
     parse_macro2(
         r#"
@@ -701,7 +701,7 @@ macro foo($id:ident) {
 
 #[test]
 fn test_parse_macro_def_rules() {
-    mark::check!(parse_macro_def_rules);
+    cov_mark::check!(parse_macro_def_rules);
 
     parse_macro2(
         r#"
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 6159d064c..6c0e22722 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -18,7 +18,7 @@
 //! // fn foo() {}
 //! ```
 //!
-//! After adding a new inline-test, run `cargo xtask codegen` to
+//! After adding a new inline-test, run `cargo test -p xtask` to
 //! extract it as a standalone text-fixture into
 //! `crates/syntax/test_data/parser/`, and run `cargo test` once to
 //! create the "gold" value.
diff --git a/crates/proc_macro_api/Cargo.toml b/crates/proc_macro_api/Cargo.toml
index f09726223..16fd56c7e 100644
--- a/crates/proc_macro_api/Cargo.toml
+++ b/crates/proc_macro_api/Cargo.toml
@@ -19,3 +19,6 @@ jod-thread = "0.1.1"
 tt = { path = "../tt", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 stdx = { path = "../stdx", version = "0.0.0" }
+snap = "1"
+object = { version = "0.23.0", default-features = false, features = ["std", "read_core", "elf", "macho", "pe", "unaligned"] }
+memmap = "0.7.0"
diff --git a/crates/proc_macro_api/src/lib.rs b/crates/proc_macro_api/src/lib.rs
index 2ea456fb0..941d0fe9e 100644
--- a/crates/proc_macro_api/src/lib.rs
+++ b/crates/proc_macro_api/src/lib.rs
@@ -5,10 +5,12 @@
 //! is used to provide basic infrastructure for communication between two
 //! processes: Client (RA itself), Server (the external program)
 
-mod rpc;
-mod process;
 pub mod msg;
+mod process;
+mod rpc;
+mod version;
 
+use base_db::{Env, ProcMacro};
 use std::{
     ffi::OsStr,
     io,
@@ -16,7 +18,6 @@ use std::{
     sync::Arc,
 };
 
-use base_db::{Env, ProcMacro};
 use tt::{SmolStr, Subtree};
 
 use crate::process::{ProcMacroProcessSrv, ProcMacroProcessThread};
@@ -75,6 +76,21 @@ impl ProcMacroClient {
     }
 
     pub fn by_dylib_path(&self, dylib_path: &Path) -> Vec<ProcMacro> {
+        match version::read_info(dylib_path) {
+            Ok(info) => {
+                if info.version.0 < 1 || info.version.1 < 47 {
+                    eprintln!("proc-macro {} built by {:#?} is not supported by Rust Analyzer, please update your rust version.", dylib_path.to_string_lossy(), info);
+                }
+            }
+            Err(err) => {
+                eprintln!(
+                    "proc-macro {} failed to find the given version. Reason: {}",
+                    dylib_path.to_string_lossy(),
+                    err
+                );
+            }
+        }
+
         let macros = match self.process.find_proc_macros(dylib_path) {
             Err(err) => {
                 eprintln!("Failed to find proc macros. Error: {:#?}", err);
diff --git a/crates/proc_macro_api/src/version.rs b/crates/proc_macro_api/src/version.rs
new file mode 100644
index 000000000..11a7fb59a
--- /dev/null
+++ b/crates/proc_macro_api/src/version.rs
@@ -0,0 +1,132 @@
+//! Reading proc-macro rustc version information from binary data
+
+use std::{
+    fs::File,
+    io::{self, Read},
+    path::Path,
+};
+
+use memmap::Mmap;
+use object::read::{File as BinaryFile, Object, ObjectSection};
+use snap::read::FrameDecoder as SnapDecoder;
+
+#[derive(Debug)]
+pub(crate) struct RustCInfo {
+    pub(crate) version: (usize, usize, usize),
+    pub(crate) channel: String,
+    pub(crate) commit: String,
+    pub(crate) date: String,
+}
+
+pub(crate) fn read_info(dylib_path: &Path) -> io::Result<RustCInfo> {
+    macro_rules! err {
+        ($e:literal) => {
+            io::Error::new(io::ErrorKind::InvalidData, $e)
+        };
+    }
+
+    let ver_str = read_version(dylib_path)?;
+    let mut items = ver_str.split_whitespace();
+    let tag = items.next().ok_or(err!("version format error"))?;
+    if tag != "rustc" {
+        return Err(err!("version format error (No rustc tag)"));
+    }
+
+    let version_part = items.next().ok_or(err!("no version string"))?;
+    let mut version_parts = version_part.split("-");
+    let version = version_parts.next().ok_or(err!("no version"))?;
+    let channel = version_parts.next().unwrap_or_default().to_string();
+
+    let commit = items.next().ok_or(err!("no commit info"))?;
+    // remove (
+    if commit.len() == 0 {
+        return Err(err!("commit format error"));
+    }
+    let commit = commit[1..].to_string();
+    let date = items.next().ok_or(err!("no date info"))?;
+    // remove )
+    if date.len() == 0 {
+        return Err(err!("date format error"));
+    }
+    let date = date[0..date.len() - 2].to_string();
+
+    let version_numbers = version
+        .split(".")
+        .map(|it| it.parse::<usize>())
+        .collect::<Result<Vec<_>, _>>()
+        .map_err(|_| err!("version number error"))?;
+
+    if version_numbers.len() != 3 {
+        return Err(err!("version number format error"));
+    }
+    let version = (version_numbers[0], version_numbers[1], version_numbers[2]);
+
+    Ok(RustCInfo { version, channel, commit, date })
+}
+
+/// This is used inside read_version() to locate the ".rustc" section
+/// from a proc macro crate's binary file.
+fn read_section<'a>(dylib_binary: &'a [u8], section_name: &str) -> io::Result<&'a [u8]> {
+    BinaryFile::parse(dylib_binary)
+        .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?
+        .section_by_name(section_name)
+        .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "section read error"))?
+        .data()
+        .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+}
+
+/// Check the version of rustc that was used to compile a proc macro crate's
+///
+/// binary file.
+/// A proc macro crate binary's ".rustc" section has following byte layout:
+/// * [b'r',b'u',b's',b't',0,0,0,5] is the first 8 bytes
+/// * ff060000 734e6150 is followed, it's the snappy format magic bytes,
+///   means bytes from here(including this sequence) are compressed in
+///   snappy compression format. Version info is inside here, so decompress
+///   this.
+/// The bytes you get after decompressing the snappy format portion has
+/// following layout:
+/// * [b'r',b'u',b's',b't',0,0,0,5] is the first 8 bytes(again)
+/// * [crate root bytes] next 4 bytes is to store crate root position,
+///   according to rustc's source code comment
+/// * [length byte] next 1 byte tells us how many bytes we should read next
+///   for the version string's utf8 bytes
+/// * [version string bytes encoded in utf8] <- GET THIS BOI
+/// * [some more bytes that we don really care but still there] :-)
+/// Check this issue for more about the bytes layout:
+/// https://github.com/rust-analyzer/rust-analyzer/issues/6174
+fn read_version(dylib_path: &Path) -> io::Result<String> {
+    let dylib_file = File::open(dylib_path)?;
+    let dylib_mmaped = unsafe { Mmap::map(&dylib_file) }?;
+
+    let dot_rustc = read_section(&dylib_mmaped, ".rustc")?;
+
+    let header = &dot_rustc[..8];
+    const EXPECTED_HEADER: [u8; 8] = [b'r', b'u', b's', b't', 0, 0, 0, 5];
+    // check if header is valid
+    if header != EXPECTED_HEADER {
+        return Err(io::Error::new(
+            io::ErrorKind::InvalidData,
+            format!("only metadata version 5 is supported, section header was: {:?}", header),
+        ));
+    }
+
+    let snappy_portion = &dot_rustc[8..];
+
+    let mut snappy_decoder = SnapDecoder::new(snappy_portion);
+
+    // the bytes before version string bytes, so this basically is:
+    // 8 bytes for [b'r',b'u',b's',b't',0,0,0,5]
+    // 4 bytes for [crate root bytes]
+    // 1 byte for length of version string
+    // so 13 bytes in total, and we should check the 13th byte
+    // to know the length
+    let mut bytes_before_version = [0u8; 13];
+    snappy_decoder.read_exact(&mut bytes_before_version)?;
+    let length = bytes_before_version[12]; // what? can't use -1 indexing?
+
+    let mut version_string_utf8 = vec![0u8; length as usize];
+    snappy_decoder.read_exact(&mut version_string_utf8)?;
+    let version_string = String::from_utf8(version_string_utf8);
+    version_string.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+}
diff --git a/crates/proc_macro_srv/Cargo.toml b/crates/proc_macro_srv/Cargo.toml
index 4c1b3036a..63b3f1532 100644
--- a/crates/proc_macro_srv/Cargo.toml
+++ b/crates/proc_macro_srv/Cargo.toml
@@ -17,9 +17,9 @@ memmap2 = "0.2.0"
 tt = { path = "../tt", version = "0.0.0" }
 mbe = { path = "../mbe", version = "0.0.0" }
 proc_macro_api = { path = "../proc_macro_api", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 cargo_metadata = "0.13"
 
 # used as proc macro test targets
diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs b/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
index e4006a5ab..e67902682 100644
--- a/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
+++ b/crates/proc_macro_srv/src/proc_macro/bridge/mod.rs
@@ -268,7 +268,7 @@ trait Mark {
     fn mark(unmarked: Self::Unmarked) -> Self;
 }
 
-/// Unwrap types wrapped by `Mark::mark` (see `Mark` for details).
+/// Unwrap types wrapped by `cov_mark::mark` (see `Mark` for details).
 trait Unmark {
     type Unmarked;
     fn unmark(self) -> Self::Unmarked;
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index f7241b711..bc6e20341 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -9,6 +9,8 @@ use cargo_metadata::{CargoOpt, MetadataCommand};
 use la_arena::{Arena, Idx};
 use paths::{AbsPath, AbsPathBuf};
 use rustc_hash::FxHashMap;
+use serde::Deserialize;
+use serde_json::from_value;
 
 use crate::build_data::BuildDataConfig;
 use crate::utf8_stdout;
@@ -104,6 +106,13 @@ pub struct PackageData {
     pub active_features: Vec<String>,
     // String representation of package id
     pub id: String,
+    // The contents of [package.metadata.rust-analyzer]
+    pub metadata: RustAnalyzerPackageMetaData,
+}
+
+#[derive(Deserialize, Default, Debug, Clone, Eq, PartialEq)]
+pub struct RustAnalyzerPackageMetaData {
+    pub rustc_private: bool,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
@@ -161,6 +170,13 @@ impl PackageData {
     }
 }
 
+#[derive(Deserialize, Default)]
+// Deserialise helper for the cargo metadata
+struct PackageMetadata {
+    #[serde(rename = "rust-analyzer")]
+    rust_analyzer: Option<RustAnalyzerPackageMetaData>,
+}
+
 impl CargoWorkspace {
     pub fn from_cargo_metadata(
         cargo_toml: &AbsPath,
@@ -244,8 +260,10 @@ impl CargoWorkspace {
 
         meta.packages.sort_by(|a, b| a.id.cmp(&b.id));
         for meta_pkg in &meta.packages {
-            let cargo_metadata::Package { id, edition, name, manifest_path, version, .. } =
-                meta_pkg;
+            let cargo_metadata::Package {
+                id, edition, name, manifest_path, version, metadata, ..
+            } = meta_pkg;
+            let meta = from_value::<PackageMetadata>(metadata.clone()).unwrap_or_default();
             let is_member = ws_members.contains(&id);
             let edition = edition
                 .parse::<Edition>()
@@ -262,6 +280,7 @@ impl CargoWorkspace {
                 dependencies: Vec::new(),
                 features: meta_pkg.features.clone().into_iter().collect(),
                 active_features: Vec::new(),
+                metadata: meta.rust_analyzer.unwrap_or_default(),
             });
             let pkg_data = &mut packages[pkg];
             pkg_by_id.insert(id, pkg);
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index 0220efdb4..1b53fcc30 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -2,11 +2,7 @@
 //! metadata` or `rust-project.json`) into representation stored in the salsa
 //! database -- `CrateGraph`.
 
-use std::{
-    fmt, fs,
-    path::{Component, Path},
-    process::Command,
-};
+use std::{collections::VecDeque, fmt, fs, path::Path, process::Command};
 
 use anyhow::{Context, Result};
 use base_db::{CrateDisplayName, CrateGraph, CrateId, CrateName, Edition, Env, FileId, ProcMacro};
@@ -60,6 +56,7 @@ impl fmt::Debug for ProjectWorkspace {
         match self {
             ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg } => f
                 .debug_struct("Cargo")
+                .field("root", &cargo.workspace_root().file_name())
                 .field("n_packages", &cargo.packages().len())
                 .field("n_sysroot_crates", &sysroot.crates().len())
                 .field(
@@ -279,11 +276,8 @@ impl ProjectWorkspace {
 
     pub fn collect_build_data_configs(&self, collector: &mut BuildDataCollector) {
         match self {
-            ProjectWorkspace::Cargo { cargo, rustc, .. } => {
+            ProjectWorkspace::Cargo { cargo, .. } => {
                 collector.add_config(&cargo.workspace_root(), cargo.build_data_config().clone());
-                if let Some(rustc) = rustc {
-                    collector.add_config(rustc.workspace_root(), rustc.build_data_config().clone());
-                }
             }
             _ => {}
         }
@@ -380,9 +374,11 @@ fn cargo_to_crate_graph(
     cfg_options.insert_atom("debug_assertions".into());
 
     let mut pkg_crates = FxHashMap::default();
-
+    // Does any crate signal to rust-analyzer that they need the rustc_private crates?
+    let mut has_private = false;
     // Next, create crates for each package, target pair
     for pkg in cargo.packages() {
+        has_private |= cargo[pkg].metadata.rustc_private;
         let mut lib_tgt = None;
         for &tgt in cargo[pkg].targets.iter() {
             if let Some(file_id) = load(&cargo[tgt].root) {
@@ -443,28 +439,66 @@ fn cargo_to_crate_graph(
         }
     }
 
-    let mut rustc_pkg_crates = FxHashMap::default();
+    if has_private {
+        // If the user provided a path to rustc sources, we add all the rustc_private crates
+        // and create dependencies on them for the crates which opt-in to that
+        if let Some(rustc_workspace) = rustc {
+            handle_rustc_crates(
+                rustc_workspace,
+                load,
+                &mut crate_graph,
+                rustc_build_data_map,
+                &cfg_options,
+                proc_macro_loader,
+                &mut pkg_to_lib_crate,
+                &public_deps,
+                cargo,
+                &pkg_crates,
+            );
+        }
+    }
+    crate_graph
+}
 
-    // If the user provided a path to rustc sources, we add all the rustc_private crates
-    // and create dependencies on them for the crates in the current workspace
-    if let Some(rustc_workspace) = rustc {
-        for pkg in rustc_workspace.packages() {
+fn handle_rustc_crates(
+    rustc_workspace: &CargoWorkspace,
+    load: &mut dyn FnMut(&AbsPath) -> Option<FileId>,
+    crate_graph: &mut CrateGraph,
+    rustc_build_data_map: Option<&FxHashMap<String, BuildData>>,
+    cfg_options: &CfgOptions,
+    proc_macro_loader: &dyn Fn(&Path) -> Vec<ProcMacro>,
+    pkg_to_lib_crate: &mut FxHashMap<la_arena::Idx<crate::PackageData>, CrateId>,
+    public_deps: &[(CrateName, CrateId)],
+    cargo: &CargoWorkspace,
+    pkg_crates: &FxHashMap<la_arena::Idx<crate::PackageData>, Vec<CrateId>>,
+) {
+    let mut rustc_pkg_crates = FxHashMap::default();
+    // The root package of the rustc-dev component is rustc_driver, so we match that
+    let root_pkg =
+        rustc_workspace.packages().find(|package| rustc_workspace[*package].name == "rustc_driver");
+    // The rustc workspace might be incomplete (such as if rustc-dev is not
+    // installed for the current toolchain) and `rustcSource` is set to discover.
+    if let Some(root_pkg) = root_pkg {
+        // Iterate through every crate in the dependency subtree of rustc_driver using BFS
+        let mut queue = VecDeque::new();
+        queue.push_back(root_pkg);
+        while let Some(pkg) = queue.pop_front() {
+            // Don't duplicate packages if they are dependended on a diamond pattern
+            // N.B. if this line is ommitted, we try to analyse over 4_800_000 crates
+            // which is not ideal
+            if rustc_pkg_crates.contains_key(&pkg) {
+                continue;
+            }
+            for dep in &rustc_workspace[pkg].dependencies {
+                queue.push_back(dep.pkg);
+            }
             for &tgt in rustc_workspace[pkg].targets.iter() {
                 if rustc_workspace[tgt].kind != TargetKind::Lib {
                     continue;
                 }
-                // Exclude alloc / core / std
-                if rustc_workspace[tgt]
-                    .root
-                    .components()
-                    .any(|c| c == Component::Normal("library".as_ref()))
-                {
-                    continue;
-                }
-
                 if let Some(file_id) = load(&rustc_workspace[tgt].root) {
                     let crate_id = add_target_crate_root(
-                        &mut crate_graph,
+                        crate_graph,
                         &rustc_workspace[pkg],
                         rustc_build_data_map.and_then(|it| it.get(&rustc_workspace[pkg].id)),
                         &cfg_options,
@@ -472,44 +506,50 @@ fn cargo_to_crate_graph(
                         file_id,
                     );
                     pkg_to_lib_crate.insert(pkg, crate_id);
-                    // Add dependencies on the core / std / alloc for rustc
+                    // Add dependencies on core / std / alloc for this crate
                     for (name, krate) in public_deps.iter() {
-                        add_dep(&mut crate_graph, crate_id, name.clone(), *krate);
+                        add_dep(crate_graph, crate_id, name.clone(), *krate);
                     }
                     rustc_pkg_crates.entry(pkg).or_insert_with(Vec::new).push(crate_id);
                 }
             }
         }
-        // Now add a dep edge from all targets of upstream to the lib
-        // target of downstream.
-        for pkg in rustc_workspace.packages() {
-            for dep in rustc_workspace[pkg].dependencies.iter() {
-                let name = CrateName::new(&dep.name).unwrap();
-                if let Some(&to) = pkg_to_lib_crate.get(&dep.pkg) {
-                    for &from in rustc_pkg_crates.get(&pkg).into_iter().flatten() {
-                        add_dep(&mut crate_graph, from, name.clone(), to);
-                    }
+    }
+    // Now add a dep edge from all targets of upstream to the lib
+    // target of downstream.
+    for pkg in rustc_pkg_crates.keys().copied() {
+        for dep in rustc_workspace[pkg].dependencies.iter() {
+            let name = CrateName::new(&dep.name).unwrap();
+            if let Some(&to) = pkg_to_lib_crate.get(&dep.pkg) {
+                for &from in rustc_pkg_crates.get(&pkg).into_iter().flatten() {
+                    add_dep(crate_graph, from, name.clone(), to);
                 }
             }
         }
-
-        // Add dependencies for all the crates of the current workspace to rustc_private libraries
-        for dep in rustc_workspace.packages() {
-            let name = CrateName::normalize_dashes(&rustc_workspace[dep].name);
-
-            if let Some(&to) = pkg_to_lib_crate.get(&dep) {
-                for pkg in cargo.packages() {
-                    if !cargo[pkg].is_member {
-                        continue;
-                    }
-                    for &from in pkg_crates.get(&pkg).into_iter().flatten() {
-                        add_dep(&mut crate_graph, from, name.clone(), to);
+    }
+    // Add a dependency on the rustc_private crates for all targets of each package
+    // which opts in
+    for dep in rustc_workspace.packages() {
+        let name = CrateName::normalize_dashes(&rustc_workspace[dep].name);
+
+        if let Some(&to) = pkg_to_lib_crate.get(&dep) {
+            for pkg in cargo.packages() {
+                let package = &cargo[pkg];
+                if !package.metadata.rustc_private {
+                    continue;
+                }
+                for &from in pkg_crates.get(&pkg).into_iter().flatten() {
+                    // Avoid creating duplicate dependencies
+                    // This avoids the situation where `from` depends on e.g. `arrayvec`, but
+                    // `rust_analyzer` thinks that it should use the one from the `rustcSource`
+                    // instead of the one from `crates.io`
+                    if !crate_graph[from].dependencies.iter().any(|d| d.name == name) {
+                        add_dep(crate_graph, from, name.clone(), to);
                     }
                 }
             }
         }
     }
-    crate_graph
 }
 
 fn add_target_crate_root(
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 8789f0852..3130785cc 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -24,7 +24,7 @@ jod-thread = "0.1.0"
 log = "0.4.8"
 lsp-types = { version = "0.88.0", features = ["proposed"] }
 parking_lot = "0.11.0"
-xflags = "0.1.2"
+xflags = "0.2.1"
 oorandom = "11.1.2"
 rustc-hash = "1.1.0"
 serde = { version = "1.0.106", features = ["derive"] }
diff --git a/crates/rust-analyzer/src/bin/flags.rs b/crates/rust-analyzer/src/bin/flags.rs
index 244912d26..3a7caaf3f 100644
--- a/crates/rust-analyzer/src/bin/flags.rs
+++ b/crates/rust-analyzer/src/bin/flags.rs
@@ -6,7 +6,9 @@ use ide_ssr::{SsrPattern, SsrRule};
 use rust_analyzer::cli::{BenchWhat, Position, Verbosity};
 use vfs::AbsPathBuf;
 
-xflags::args_parser! {
+xflags::xflags! {
+    src "./src/bin/flags.rs"
+
     /// LSP server for the Rust programming language.
     cmd rust-analyzer {
         /// Verbosity level, can be repeated multiple times.
@@ -120,7 +122,7 @@ xflags::args_parser! {
 
 // generated start
 // The following code is generated by `xflags` macro.
-// Run `env XFLAGS_DUMP= cargo build` to regenerate.
+// Run `env UPDATE_XFLAGS=1 cargo build` to regenerate.
 #[derive(Debug)]
 pub struct RustAnalyzer {
     pub verbose: u32,
@@ -158,7 +160,7 @@ pub struct Parse {
 }
 
 #[derive(Debug)]
-pub struct Symbols {}
+pub struct Symbols;
 
 #[derive(Debug)]
 pub struct Highlight {
@@ -211,14 +213,13 @@ pub struct Search {
 }
 
 #[derive(Debug)]
-pub struct ProcMacro {}
+pub struct ProcMacro;
 
 impl RustAnalyzer {
-    pub const HELP: &'static str = Self::_HELP;
+    pub const HELP: &'static str = Self::HELP_;
 
     pub fn from_env() -> xflags::Result<Self> {
-        let mut p = xflags::rt::Parser::new_from_env();
-        Self::_parse(&mut p)
+        Self::from_env_()
     }
 }
 // generated end
diff --git a/crates/rust-analyzer/src/cli/analysis_bench.rs b/crates/rust-analyzer/src/cli/analysis_bench.rs
index 3bd7e678d..49994824f 100644
--- a/crates/rust-analyzer/src/cli/analysis_bench.rs
+++ b/crates/rust-analyzer/src/cli/analysis_bench.rs
@@ -108,7 +108,11 @@ impl BenchCmd {
                         add_call_parenthesis: true,
                         add_call_argument_snippets: true,
                         snippet_cap: SnippetCap::new(true),
-                        insert_use: InsertUseConfig { merge: None, prefix_kind: PrefixKind::Plain },
+                        insert_use: InsertUseConfig {
+                            merge: None,
+                            prefix_kind: PrefixKind::Plain,
+                            group: true,
+                        },
                     };
                     let res = do_work(&mut host, file_id, |analysis| {
                         analysis.completions(&options, file_position)
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 367136702..8af7871ac 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -16,7 +16,6 @@ use ide_db::helpers::{
     insert_use::{InsertUseConfig, MergeBehavior},
     SnippetCap,
 };
-use itertools::Itertools;
 use lsp_types::{ClientCapabilities, MarkupKind};
 use project_model::{CargoConfig, ProjectJson, ProjectJsonData, ProjectManifest, RustcSource};
 use rustc_hash::FxHashSet;
@@ -35,7 +34,8 @@ config_data! {
         assist_importMergeBehaviour: MergeBehaviorDef  = "\"full\"",
         /// The path structure for newly inserted paths to use.
         assist_importPrefix: ImportPrefixDef           = "\"plain\"",
-
+        /// Group inserted imports by the [following order](https://rust-analyzer.github.io/manual.html#auto-import). Groups are separated by newlines.
+        assist_importGroup: bool                       = "true",
         /// Show function name and docs in parameter hints.
         callInfo_full: bool = "true",
 
@@ -48,7 +48,7 @@ config_data! {
         cargo_features: Vec<String>      = "[]",
         /// Run build scripts (`build.rs`) for more precise code analysis.
         cargo_runBuildScripts |
-        cargo_loadOutDirsFromCheck: bool = "false",
+        cargo_loadOutDirsFromCheck: bool = "true",
         /// Do not activate the `default` feature.
         cargo_noDefaultFeatures: bool    = "false",
         /// Compilation target (target triple).
@@ -97,13 +97,15 @@ config_data! {
         diagnostics_enableExperimental: bool    = "true",
         /// List of rust-analyzer diagnostics to disable.
         diagnostics_disabled: FxHashSet<String> = "[]",
-        /// List of warnings that should be displayed with info severity.\n\nThe
-        /// warnings will be indicated by a blue squiggly underline in code and
-        /// a blue icon in the `Problems Panel`.
+        /// List of warnings that should be displayed with info severity.
+        ///
+        /// The warnings will be indicated by a blue squiggly underline in code
+        /// and a blue icon in the `Problems Panel`.
         diagnostics_warningsAsHint: Vec<String> = "[]",
-        /// List of warnings that should be displayed with hint severity.\n\nThe
-        /// warnings will be indicated by faded text or three dots in code and
-        /// will not show up in the `Problems Panel`.
+        /// List of warnings that should be displayed with hint severity.
+        ///
+        /// The warnings will be indicated by faded text or three dots in code
+        /// and will not show up in the `Problems Panel`.
         diagnostics_warningsAsInfo: Vec<String> = "[]",
 
         /// Controls file watching implementation.
@@ -157,7 +159,9 @@ config_data! {
         lens_references: bool = "false",
 
         /// Disable project auto-discovery in favor of explicitly specified set
-        /// of projects.\n\nElements must be paths pointing to `Cargo.toml`,
+        /// of projects.
+        ///
+        /// Elements must be paths pointing to `Cargo.toml`,
         /// `rust-project.json`, or JSON objects in `rust-project.json` format.
         linkedProjects: Vec<ManifestOrProjectJson> = "[]",
 
@@ -176,12 +180,17 @@ config_data! {
         /// Command to be executed instead of 'cargo' for runnables.
         runnables_overrideCargo: Option<String> = "null",
         /// Additional arguments to be passed to cargo for runnables such as
-        /// tests or binaries.\nFor example, it may be `--release`.
+        /// tests or binaries. For example, it may be `--release`.
         runnables_cargoExtraArgs: Vec<String>   = "[]",
 
-        /// Path to the rust compiler sources, for usage in rustc_private projects, or "discover"
-        /// to try to automatically find it.
-        rustcSource : Option<String> = "null",
+        /// Path to the Cargo.toml of the rust compiler workspace, for usage in rustc_private
+        /// projects, or "discover" to try to automatically find it.
+        ///
+        /// Any project which uses rust-analyzer with the rustcPrivate
+        /// crates must set `[package.metadata.rust-analyzer] rustc_private=true` to use it.
+        ///
+        /// This option is not reloaded automatically; you must restart rust-analyzer for it to take effect.
+        rustcSource: Option<String> = "null",
 
         /// Additional arguments to `rustfmt`.
         rustfmt_extraArgs: Vec<String>               = "[]",
@@ -386,6 +395,9 @@ impl Config {
     pub fn work_done_progress(&self) -> bool {
         try_or!(self.caps.window.as_ref()?.work_done_progress?, false)
     }
+    pub fn will_rename(&self) -> bool {
+        try_or!(self.caps.workspace.as_ref()?.file_operations.as_ref()?.will_rename?, false)
+    }
     pub fn code_action_resolve(&self) -> bool {
         try_or!(
             self.caps
@@ -574,6 +586,7 @@ impl Config {
                 ImportPrefixDef::ByCrate => PrefixKind::ByCrate,
                 ImportPrefixDef::BySelf => PrefixKind::BySelf,
             },
+            group: self.data.assist_importGroup,
         }
     }
     pub fn completion(&self) -> CompletionConfig {
@@ -758,7 +771,8 @@ fn schema(fields: &[(&'static str, &'static str, &[&str], &str)]) -> serde_json:
 }
 
 fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json::Value {
-    let doc = doc.iter().map(|it| it.trim()).join(" ");
+    let doc = doc_comment_to_string(doc);
+    let doc = doc.trim_end_matches('\n');
     assert!(
         doc.ends_with('.') && doc.starts_with(char::is_uppercase),
         "bad docs for {}: {:?}",
@@ -847,21 +861,26 @@ fn manual(fields: &[(&'static str, &'static str, &[&str], &str)]) -> String {
         .iter()
         .map(|(field, _ty, doc, default)| {
             let name = format!("rust-analyzer.{}", field.replace("_", "."));
-            format!("[[{}]]{} (default: `{}`)::\n{}\n", name, name, default, doc.join(" "))
+            let doc = doc_comment_to_string(*doc);
+            format!("[[{}]]{} (default: `{}`)::\n+\n--\n{}--\n", name, name, default, doc)
         })
         .collect::<String>()
 }
 
+fn doc_comment_to_string(doc: &[&str]) -> String {
+    doc.iter().map(|it| it.strip_prefix(' ').unwrap_or(it)).map(|it| format!("{}\n", it)).collect()
+}
+
 #[cfg(test)]
 mod tests {
     use std::fs;
 
-    use test_utils::project_dir;
+    use test_utils::{ensure_file_contents, project_root};
 
     use super::*;
 
     #[test]
-    fn schema_in_sync_with_package_json() {
+    fn generate_package_json_config() {
         let s = Config::json_schema();
         let schema = format!("{:#}", s);
         let mut schema = schema
@@ -874,7 +893,7 @@ mod tests {
             .to_string();
         schema.push_str(",\n");
 
-        let package_json_path = project_dir().join("editors/code/package.json");
+        let package_json_path = project_root().join("editors/code/package.json");
         let mut package_json = fs::read_to_string(&package_json_path).unwrap();
 
         let start_marker = "                \"$generated-start\": false,\n";
@@ -882,26 +901,20 @@ mod tests {
 
         let start = package_json.find(start_marker).unwrap() + start_marker.len();
         let end = package_json.find(end_marker).unwrap();
+
         let p = remove_ws(&package_json[start..end]);
         let s = remove_ws(&schema);
-
         if !p.contains(&s) {
             package_json.replace_range(start..end, &schema);
-            fs::write(&package_json_path, &mut package_json).unwrap();
-            panic!("new config, updating package.json")
+            ensure_file_contents(&package_json_path, &package_json)
         }
     }
 
     #[test]
-    fn schema_in_sync_with_docs() {
-        let docs_path = project_dir().join("docs/user/generated_config.adoc");
-        let current = fs::read_to_string(&docs_path).unwrap();
+    fn generate_config_documentation() {
+        let docs_path = project_root().join("docs/user/generated_config.adoc");
         let expected = ConfigData::manual();
-
-        if remove_ws(&current) != remove_ws(&expected) {
-            fs::write(&docs_path, expected).unwrap();
-            panic!("updated config manual");
-        }
+        ensure_file_contents(&docs_path, &expected);
     }
 
     fn remove_ws(text: &str) -> String {
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 4f6f250d6..6cc433cb8 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -697,7 +697,6 @@ pub(crate) fn handle_completion_resolve(
             FilePosition { file_id, offset },
             &resolve_data.full_import_path,
             resolve_data.imported_name,
-            resolve_data.import_for_trait_assoc_item,
         )?
         .into_iter()
         .flat_map(|edit| edit.into_iter().map(|indel| to_proto::text_edit(&line_index, indel)))
@@ -800,8 +799,18 @@ pub(crate) fn handle_rename(
     let _p = profile::span("handle_rename");
     let position = from_proto::file_position(&snap, params.text_document_position)?;
 
-    let change =
+    let mut change =
         snap.analysis.rename(position, &*params.new_name)?.map_err(to_proto::rename_error)?;
+
+    // this is kind of a hack to prevent double edits from happening when moving files
+    // When a module gets renamed by renaming the mod declaration this causes the file to move
+    // which in turn will trigger a WillRenameFiles request to the server for which we reply with a
+    // a second identical set of renames, the client will then apply both edits causing incorrect edits
+    // with this we only emit source_file_edits in the WillRenameFiles response which will do the rename instead
+    // See https://github.com/microsoft/vscode-languageserver-node/issues/752 for more info
+    if !change.file_system_edits.is_empty() && snap.config.will_rename() {
+        change.source_file_edits.clear();
+    }
     let workspace_edit = to_proto::workspace_edit(&snap, change)?;
     Ok(Some(workspace_edit))
 }
@@ -1135,20 +1144,13 @@ pub(crate) fn handle_document_highlight(
         None
     };
 
-    let res = refs
-        .references
-        .get(&position.file_id)
-        .map(|file_refs| {
-            file_refs
-                .into_iter()
-                .map(|&(range, access)| DocumentHighlight {
-                    range: to_proto::range(&line_index, range),
-                    kind: access.map(to_proto::document_highlight_kind),
-                })
-                .chain(decl)
-                .collect()
-        })
-        .unwrap_or_default();
+    let file_refs = refs.references.get(&position.file_id).map_or(&[][..], Vec::as_slice);
+    let mut res = Vec::with_capacity(file_refs.len() + 1);
+    res.extend(decl);
+    res.extend(file_refs.iter().map(|&(range, access)| DocumentHighlight {
+        range: to_proto::range(&line_index, range),
+        kind: access.map(to_proto::document_highlight_kind),
+    }));
     Ok(Some(res))
 }
 
@@ -1525,7 +1527,6 @@ struct CompletionResolveData {
     position: lsp_types::TextDocumentPositionParams,
     full_import_path: String,
     imported_name: String,
-    import_for_trait_assoc_item: bool,
 }
 
 fn fill_resolve_data(
@@ -1534,15 +1535,13 @@ fn fill_resolve_data(
     position: &TextDocumentPositionParams,
 ) -> Option<()> {
     let import_edit = item.import_to_add()?;
-    let full_import_path = import_edit.import_path.to_string();
-    let imported_name = import_edit.import_path.segments().last()?.to_string();
+    let import_path = &import_edit.import.import_path;
 
     *resolve_data = Some(
         to_value(CompletionResolveData {
             position: position.to_owned(),
-            full_import_path,
-            imported_name,
-            import_for_trait_assoc_item: import_edit.import_for_trait_assoc_item,
+            full_import_path: import_path.to_string(),
+            imported_name: import_path.segments().last()?.to_string(),
         })
         .unwrap(),
     );
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index c1ca88df6..1a8cdadad 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -6,9 +6,10 @@ use std::{
 
 use ide::{
     Annotation, AnnotationKind, Assist, AssistKind, CallInfo, CompletionItem, CompletionItemKind,
-    Documentation, FileId, FileRange, FileSystemEdit, Fold, FoldKind, Highlight, HlMod, HlPunct,
-    HlRange, HlTag, Indel, InlayHint, InlayKind, InsertTextFormat, Markup, NavigationTarget,
-    ReferenceAccess, RenameError, Runnable, Severity, SourceChange, TextEdit, TextRange, TextSize,
+    CompletionRelevance, Documentation, FileId, FileRange, FileSystemEdit, Fold, FoldKind,
+    Highlight, HlMod, HlPunct, HlRange, HlTag, Indel, InlayHint, InlayKind, InsertTextFormat,
+    Markup, NavigationTarget, ReferenceAccess, RenameError, Runnable, Severity, SourceChange,
+    TextEdit, TextRange, TextSize,
 };
 use ide_db::SymbolKind;
 use itertools::Itertools;
@@ -173,20 +174,14 @@ pub(crate) fn snippet_text_edit_vec(
 
 pub(crate) fn completion_item(
     line_index: &LineIndex,
-    completion_item: CompletionItem,
+    item: CompletionItem,
 ) -> Vec<lsp_types::CompletionItem> {
-    fn set_score(res: &mut lsp_types::CompletionItem, label: &str) {
-        res.preselect = Some(true);
-        // HACK: sort preselect items first
-        res.sort_text = Some(format!(" {}", label));
-    }
-
     let mut additional_text_edits = Vec::new();
     let mut text_edit = None;
     // LSP does not allow arbitrary edits in completion, so we have to do a
     // non-trivial mapping here.
-    let source_range = completion_item.source_range();
-    for indel in completion_item.text_edit().iter() {
+    let source_range = item.source_range();
+    for indel in item.text_edit().iter() {
         if indel.delete.contains_range(source_range) {
             text_edit = Some(if indel.delete == source_range {
                 self::text_edit(line_index, indel.clone())
@@ -207,46 +202,61 @@ pub(crate) fn completion_item(
     }
     let text_edit = text_edit.unwrap();
 
-    let mut res = lsp_types::CompletionItem {
-        label: completion_item.label().to_string(),
-        detail: completion_item.detail().map(|it| it.to_string()),
-        filter_text: Some(completion_item.lookup().to_string()),
-        kind: completion_item.kind().map(completion_item_kind),
+    let mut lsp_item = lsp_types::CompletionItem {
+        label: item.label().to_string(),
+        detail: item.detail().map(|it| it.to_string()),
+        filter_text: Some(item.lookup().to_string()),
+        kind: item.kind().map(completion_item_kind),
         text_edit: Some(text_edit.into()),
         additional_text_edits: Some(additional_text_edits),
-        documentation: completion_item.documentation().map(documentation),
-        deprecated: Some(completion_item.deprecated()),
+        documentation: item.documentation().map(documentation),
+        deprecated: Some(item.deprecated()),
         ..Default::default()
     };
 
-    if completion_item.score().is_some() {
-        set_score(&mut res, completion_item.label());
+    fn set_score(res: &mut lsp_types::CompletionItem, relevance: CompletionRelevance) {
+        if relevance.is_relevant() {
+            res.preselect = Some(true);
+        }
+        // The relevance needs to be inverted to come up with a sort score
+        // because the client will sort ascending.
+        let sort_score = relevance.score() ^ 0xFF_FF_FF_FF;
+        // Zero pad the string to ensure values can be properly sorted
+        // by the client. Hex format is used because it is easier to
+        // visually compare very large values, which the sort text
+        // tends to be since it is the opposite of the score.
+        res.sort_text = Some(format!("{:08x}", sort_score));
     }
 
-    if completion_item.deprecated() {
-        res.tags = Some(vec![lsp_types::CompletionItemTag::Deprecated])
+    set_score(&mut lsp_item, item.relevance());
+
+    if item.deprecated() {
+        lsp_item.tags = Some(vec![lsp_types::CompletionItemTag::Deprecated])
     }
 
-    if completion_item.trigger_call_info() {
-        res.command = Some(command::trigger_parameter_hints());
+    if item.trigger_call_info() {
+        lsp_item.command = Some(command::trigger_parameter_hints());
     }
 
-    let mut all_results = match completion_item.ref_match() {
-        Some(ref_match) => {
-            let mut refed = res.clone();
-            let (mutability, _score) = ref_match;
-            let label = format!("&{}{}", mutability.as_keyword_for_ref(), refed.label);
-            set_score(&mut refed, &label);
-            refed.label = label;
-            vec![res, refed]
+    let mut res = match item.ref_match() {
+        Some((mutability, relevance)) => {
+            let mut lsp_item_with_ref = lsp_item.clone();
+            set_score(&mut lsp_item_with_ref, relevance);
+            lsp_item_with_ref.label =
+                format!("&{}{}", mutability.as_keyword_for_ref(), lsp_item_with_ref.label);
+            if let Some(lsp_types::CompletionTextEdit::Edit(it)) = &mut lsp_item_with_ref.text_edit
+            {
+                it.new_text = format!("&{}{}", mutability.as_keyword_for_ref(), it.new_text);
+            }
+            vec![lsp_item_with_ref, lsp_item]
         }
-        None => vec![res],
+        None => vec![lsp_item],
     };
 
-    for mut r in all_results.iter_mut() {
-        r.insert_text_format = Some(insert_text_format(completion_item.insert_text_format()));
+    for lsp_item in res.iter_mut() {
+        lsp_item.insert_text_format = Some(insert_text_format(item.insert_text_format()));
     }
-    all_results
+    res
 }
 
 pub(crate) fn signature_help(
@@ -1087,7 +1097,11 @@ mod tests {
                     add_call_parenthesis: true,
                     add_call_argument_snippets: true,
                     snippet_cap: SnippetCap::new(true),
-                    insert_use: InsertUseConfig { merge: None, prefix_kind: PrefixKind::Plain },
+                    insert_use: InsertUseConfig {
+                        merge: None,
+                        prefix_kind: PrefixKind::Plain,
+                        group: true,
+                    },
                 },
                 ide_db::base_db::FilePosition { file_id, offset },
             )
@@ -1101,13 +1115,15 @@ mod tests {
         expect_test::expect![[r#"
             [
                 (
-                    "arg",
-                    None,
+                    "&arg",
+                    Some(
+                        "fffffffd",
+                    ),
                 ),
                 (
-                    "&arg",
+                    "arg",
                     Some(
-                        " &arg",
+                        "fffffffe",
                     ),
                 ),
             ]
diff --git a/crates/rust-analyzer/tests/rust-analyzer/support.rs b/crates/rust-analyzer/tests/rust-analyzer/support.rs
index 6b774073d..cd0c91481 100644
--- a/crates/rust-analyzer/tests/rust-analyzer/support.rs
+++ b/crates/rust-analyzer/tests/rust-analyzer/support.rs
@@ -13,7 +13,7 @@ use project_model::ProjectManifest;
 use rust_analyzer::{config::Config, lsp_ext, main_loop};
 use serde::Serialize;
 use serde_json::{json, to_string_pretty, Value};
-use test_utils::{find_mismatch, Fixture};
+use test_utils::Fixture;
 use vfs::AbsPathBuf;
 
 use crate::testdir::TestDir;
@@ -279,3 +279,98 @@ fn recv_timeout(receiver: &Receiver<Message>) -> Result<Option<Message>, Timeout
         recv(after(timeout)) -> _ => Err(Timeout),
     }
 }
+
+// Comparison functionality borrowed from cargo:
+
+/// Compares JSON object for approximate equality.
+/// You can use `[..]` wildcard in strings (useful for OS dependent things such
+/// as paths). You can use a `"{...}"` string literal as a wildcard for
+/// arbitrary nested JSON. Arrays are sorted before comparison.
+fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a Value, &'a Value)> {
+    match (expected, actual) {
+        (Value::Number(l), Value::Number(r)) if l == r => None,
+        (Value::Bool(l), Value::Bool(r)) if l == r => None,
+        (Value::String(l), Value::String(r)) if lines_match(l, r) => None,
+        (Value::Array(l), Value::Array(r)) => {
+            if l.len() != r.len() {
+                return Some((expected, actual));
+            }
+
+            let mut l = l.iter().collect::<Vec<_>>();
+            let mut r = r.iter().collect::<Vec<_>>();
+
+            l.retain(|l| match r.iter().position(|r| find_mismatch(l, r).is_none()) {
+                Some(i) => {
+                    r.remove(i);
+                    false
+                }
+                None => true,
+            });
+
+            if !l.is_empty() {
+                assert!(!r.is_empty());
+                Some((&l[0], &r[0]))
+            } else {
+                assert_eq!(r.len(), 0);
+                None
+            }
+        }
+        (Value::Object(l), Value::Object(r)) => {
+            fn sorted_values(obj: &serde_json::Map<String, Value>) -> Vec<&Value> {
+                let mut entries = obj.iter().collect::<Vec<_>>();
+                entries.sort_by_key(|it| it.0);
+                entries.into_iter().map(|(_k, v)| v).collect::<Vec<_>>()
+            }
+
+            let same_keys = l.len() == r.len() && l.keys().all(|k| r.contains_key(k));
+            if !same_keys {
+                return Some((expected, actual));
+            }
+
+            let l = sorted_values(l);
+            let r = sorted_values(r);
+
+            l.into_iter().zip(r).filter_map(|(l, r)| find_mismatch(l, r)).next()
+        }
+        (Value::Null, Value::Null) => None,
+        // magic string literal "{...}" acts as wildcard for any sub-JSON
+        (Value::String(l), _) if l == "{...}" => None,
+        _ => Some((expected, actual)),
+    }
+}
+
+/// Compare a line with an expected pattern.
+/// - Use `[..]` as a wildcard to match 0 or more characters on the same line
+///   (similar to `.*` in a regex).
+fn lines_match(expected: &str, actual: &str) -> bool {
+    // Let's not deal with / vs \ (windows...)
+    // First replace backslash-escaped backslashes with forward slashes
+    // which can occur in, for example, JSON output
+    let expected = expected.replace(r"\\", "/").replace(r"\", "/");
+    let mut actual: &str = &actual.replace(r"\\", "/").replace(r"\", "/");
+    for (i, part) in expected.split("[..]").enumerate() {
+        match actual.find(part) {
+            Some(j) => {
+                if i == 0 && j != 0 {
+                    return false;
+                }
+                actual = &actual[j + part.len()..];
+            }
+            None => return false,
+        }
+    }
+    actual.is_empty() || expected.ends_with("[..]")
+}
+
+#[test]
+fn lines_match_works() {
+    assert!(lines_match("a b", "a b"));
+    assert!(lines_match("a[..]b", "a b"));
+    assert!(lines_match("a[..]", "a b"));
+    assert!(lines_match("[..]", "a b"));
+    assert!(lines_match("[..]b", "a b"));
+
+    assert!(!lines_match("[..]b", "c"));
+    assert!(!lines_match("b", "c"));
+    assert!(!lines_match("b", "cb"));
+}
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 9ee3a8586..05fca5dc4 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -11,9 +11,10 @@ edition = "2018"
 doctest = false
 
 [dependencies]
+cov-mark = "1.1"
 itertools = "0.10.0"
 rowan = "0.12.2"
-rustc_lexer = { version = "709.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "710.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
@@ -24,10 +25,10 @@ serde = { version = "1.0.106", features = ["derive"] }
 stdx = { path = "../stdx", version = "0.0.0" }
 text_edit = { path = "../text_edit", version = "0.0.0" }
 parser = { path = "../parser", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 walkdir = "2.3.1"
 rayon = "1"
 expect-test = "1.1"
diff --git a/crates/syntax/src/algo.rs b/crates/syntax/src/algo.rs
index 2ff92f9f6..b13252eec 100644
--- a/crates/syntax/src/algo.rs
+++ b/crates/syntax/src/algo.rs
@@ -10,7 +10,6 @@ use std::{
 use indexmap::IndexMap;
 use itertools::Itertools;
 use rustc_hash::FxHashMap;
-use test_utils::mark;
 use text_edit::TextEditBuilder;
 
 use crate::{
@@ -184,7 +183,7 @@ pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
         let (lhs, rhs) = match lhs.as_node().zip(rhs.as_node()) {
             Some((lhs, rhs)) => (lhs, rhs),
             _ => {
-                mark::hit!(diff_node_token_replace);
+                cov_mark::hit!(diff_node_token_replace);
                 diff.replacements.insert(lhs, rhs);
                 return;
             }
@@ -202,19 +201,19 @@ pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
                 (None, Some(element)) => {
                     let insert_pos = match last_lhs.clone() {
                         Some(prev) => {
-                            mark::hit!(diff_insert);
+                            cov_mark::hit!(diff_insert);
                             TreeDiffInsertPos::After(prev)
                         }
                         // first iteration, insert into out parent as the first child
                         None => {
-                            mark::hit!(diff_insert_as_first_child);
+                            cov_mark::hit!(diff_insert_as_first_child);
                             TreeDiffInsertPos::AsFirstChild(lhs.clone().into())
                         }
                     };
                     diff.insertions.entry(insert_pos).or_insert_with(Vec::new).push(element);
                 }
                 (Some(element), None) => {
-                    mark::hit!(diff_delete);
+                    cov_mark::hit!(diff_delete);
                     diff.deletions.push(element);
                 }
                 (Some(ref lhs_ele), Some(ref rhs_ele)) if syntax_element_eq(lhs_ele, rhs_ele) => {}
@@ -228,7 +227,7 @@ pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
                     let mut insert = false;
                     while let Some(rhs_child) = rhs_children_clone.next() {
                         if syntax_element_eq(&lhs_ele, &rhs_child) {
-                            mark::hit!(diff_insertions);
+                            cov_mark::hit!(diff_insertions);
                             insert = true;
                             break;
                         } else {
@@ -240,7 +239,7 @@ pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
                         let insert_pos = if let Some(prev) = last_lhs.clone().filter(|_| insert) {
                             TreeDiffInsertPos::After(prev)
                         } else {
-                            mark::hit!(insert_first_child);
+                            cov_mark::hit!(insert_first_child);
                             TreeDiffInsertPos::AsFirstChild(lhs.clone().into())
                         };
 
@@ -635,14 +634,13 @@ mod tests {
     use expect_test::{expect, Expect};
     use itertools::Itertools;
     use parser::SyntaxKind;
-    use test_utils::mark;
     use text_edit::TextEdit;
 
     use crate::{AstNode, SyntaxElement};
 
     #[test]
     fn replace_node_token() {
-        mark::check!(diff_node_token_replace);
+        cov_mark::check!(diff_node_token_replace);
         check_diff(
             r#"use node;"#,
             r#"ident"#,
@@ -666,7 +664,7 @@ mod tests {
 
     #[test]
     fn replace_parent() {
-        mark::check!(diff_insert_as_first_child);
+        cov_mark::check!(diff_insert_as_first_child);
         check_diff(
             r#""#,
             r#"use foo::bar;"#,
@@ -689,7 +687,7 @@ mod tests {
 
     #[test]
     fn insert_last() {
-        mark::check!(diff_insert);
+        cov_mark::check!(diff_insert);
         check_diff(
             r#"
 use foo;
@@ -774,7 +772,7 @@ use baz;"#,
 
     #[test]
     fn first_child_insertion() {
-        mark::check!(insert_first_child);
+        cov_mark::check!(insert_first_child);
         check_diff(
             r#"fn main() {
         stdi
@@ -804,7 +802,7 @@ use baz;"#,
 
     #[test]
     fn delete_last() {
-        mark::check!(diff_delete);
+        cov_mark::check!(diff_delete);
         check_diff(
             r#"use foo;
             use bar;"#,
@@ -828,7 +826,7 @@ use baz;"#,
 
     #[test]
     fn delete_middle() {
-        mark::check!(diff_insertions);
+        cov_mark::check!(diff_insertions);
         check_diff(
             r#"
 use expect_test::{expect, Expect};
diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs
index b6c5de658..05a6b0b25 100644
--- a/crates/syntax/src/ast/make.rs
+++ b/crates/syntax/src/ast/make.rs
@@ -91,6 +91,10 @@ pub fn path_from_segments(
     })
 }
 
+pub fn path_from_text(text: &str) -> ast::Path {
+    ast_from_text(&format!("fn main() {{ let test = {}; }}", text))
+}
+
 pub fn glob_use_tree() -> ast::UseTree {
     ast_from_text("use *;")
 }
@@ -218,6 +222,9 @@ pub fn expr_if(
     };
     expr_from_text(&format!("if {} {} {}", condition, then_branch, else_branch))
 }
+pub fn expr_for_loop(pat: ast::Pat, expr: ast::Expr, block: ast::BlockExpr) -> ast::Expr {
+    expr_from_text(&format!("for {} in {} {}", pat, expr, block))
+}
 pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
     let token = token(op);
     expr_from_text(&format!("{}{}", token, expr))
diff --git a/crates/syntax/src/lib.rs b/crates/syntax/src/lib.rs
index 11294c5b2..09e212e8c 100644
--- a/crates/syntax/src/lib.rs
+++ b/crates/syntax/src/lib.rs
@@ -37,6 +37,7 @@ pub mod algo;
 pub mod ast;
 #[doc(hidden)]
 pub mod fuzz;
+pub mod utils;
 
 use std::{marker::PhantomData, sync::Arc};
 
diff --git a/crates/syntax/src/tests.rs b/crates/syntax/src/tests.rs
index b2c06e24f..ba0ccfaed 100644
--- a/crates/syntax/src/tests.rs
+++ b/crates/syntax/src/tests.rs
@@ -7,7 +7,7 @@ use std::{
 use ast::NameOwner;
 use expect_test::expect_file;
 use rayon::prelude::*;
-use test_utils::{bench, bench_fixture, project_dir, skip_slow_tests};
+use test_utils::{bench, bench_fixture, project_root, skip_slow_tests};
 
 use crate::{ast, fuzz, tokenize, AstNode, SourceFile, SyntaxError, TextRange, TextSize, Token};
 
@@ -153,7 +153,7 @@ fn reparse_fuzz_tests() {
 /// Test that Rust-analyzer can parse and validate the rust-analyzer
 #[test]
 fn self_hosting_parsing() {
-    let dir = project_dir().join("crates");
+    let dir = project_root().join("crates");
     let files = walkdir::WalkDir::new(dir)
         .into_iter()
         .filter_entry(|entry| {
@@ -193,7 +193,7 @@ fn self_hosting_parsing() {
 }
 
 fn test_data_dir() -> PathBuf {
-    project_dir().join("crates/syntax/test_data")
+    project_root().join("crates/syntax/test_data")
 }
 
 fn assert_errors_are_present(errors: &[SyntaxError], path: &Path) {
diff --git a/crates/syntax/src/utils.rs b/crates/syntax/src/utils.rs
new file mode 100644
index 000000000..f4c02518b
--- /dev/null
+++ b/crates/syntax/src/utils.rs
@@ -0,0 +1,43 @@
+//! A set of utils methods to reuse on other abstraction levels
+
+use itertools::Itertools;
+
+use crate::{ast, match_ast, AstNode};
+
+pub fn path_to_string_stripping_turbo_fish(path: &ast::Path) -> String {
+    path.syntax()
+        .children()
+        .filter_map(|node| {
+            match_ast! {
+                match node {
+                    ast::PathSegment(it) => {
+                        Some(it.name_ref()?.to_string())
+                    },
+                    ast::Path(it) => {
+                        Some(path_to_string_stripping_turbo_fish(&it))
+                    },
+                    _ => None,
+                }
+            }
+        })
+        .join("::")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::path_to_string_stripping_turbo_fish;
+    use crate::ast::make;
+
+    #[test]
+    fn turbofishes_are_stripped() {
+        assert_eq!("Vec", path_to_string_stripping_turbo_fish(&make::path_from_text("Vec::<i32>")),);
+        assert_eq!(
+            "Vec::new",
+            path_to_string_stripping_turbo_fish(&make::path_from_text("Vec::<i32>::new")),
+        );
+        assert_eq!(
+            "Vec::new",
+            path_to_string_stripping_turbo_fish(&make::path_from_text("Vec::new()")),
+        );
+    }
+}
diff --git a/crates/test_utils/Cargo.toml b/crates/test_utils/Cargo.toml
index 2a65000b8..87bab7a08 100644
--- a/crates/test_utils/Cargo.toml
+++ b/crates/test_utils/Cargo.toml
@@ -13,7 +13,6 @@ doctest = false
 # Avoid adding deps here, this crate is widely used in tests it should compile fast!
 dissimilar = "1.0.2"
 text-size = "1.0.0"
-serde_json = "1.0.48"
 rustc-hash = "1.1.0"
 
 stdx = { path = "../stdx", version = "0.0.0" }
diff --git a/crates/test_utils/src/bench_fixture.rs b/crates/test_utils/src/bench_fixture.rs
index d775e2cc9..3a37c4473 100644
--- a/crates/test_utils/src/bench_fixture.rs
+++ b/crates/test_utils/src/bench_fixture.rs
@@ -4,7 +4,7 @@ use std::fs;
 
 use stdx::format_to;
 
-use crate::project_dir;
+use crate::project_root;
 
 pub fn big_struct() -> String {
     let n = 1_000;
@@ -32,11 +32,11 @@ struct S{} {{
 }
 
 pub fn glorious_old_parser() -> String {
-    let path = project_dir().join("bench_data/glorious_old_parser");
+    let path = project_root().join("bench_data/glorious_old_parser");
     fs::read_to_string(&path).unwrap()
 }
 
 pub fn numerous_macro_rules() -> String {
-    let path = project_dir().join("bench_data/numerous_macro_rules");
+    let path = project_root().join("bench_data/numerous_macro_rules");
     fs::read_to_string(&path).unwrap()
 }
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 5be4a64fc..c5f859790 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -6,20 +6,17 @@
 //! * Extracting markup (mainly, `$0` markers) out of fixture strings.
 //! * marks (see the eponymous module).
 
-#[macro_use]
-pub mod mark;
 pub mod bench_fixture;
 mod fixture;
 
 use std::{
     convert::{TryFrom, TryInto},
     env, fs,
-    path::PathBuf,
+    path::{Path, PathBuf},
 };
 
 use profile::StopWatch;
-use serde_json::Value;
-use stdx::lines_with_ends;
+use stdx::{is_ci, lines_with_ends};
 use text_size::{TextRange, TextSize};
 
 pub use dissimilar::diff as __diff;
@@ -281,101 +278,6 @@ fn main() {
     );
 }
 
-// Comparison functionality borrowed from cargo:
-
-/// Compare a line with an expected pattern.
-/// - Use `[..]` as a wildcard to match 0 or more characters on the same line
-///   (similar to `.*` in a regex).
-pub fn lines_match(expected: &str, actual: &str) -> bool {
-    // Let's not deal with / vs \ (windows...)
-    // First replace backslash-escaped backslashes with forward slashes
-    // which can occur in, for example, JSON output
-    let expected = expected.replace(r"\\", "/").replace(r"\", "/");
-    let mut actual: &str = &actual.replace(r"\\", "/").replace(r"\", "/");
-    for (i, part) in expected.split("[..]").enumerate() {
-        match actual.find(part) {
-            Some(j) => {
-                if i == 0 && j != 0 {
-                    return false;
-                }
-                actual = &actual[j + part.len()..];
-            }
-            None => return false,
-        }
-    }
-    actual.is_empty() || expected.ends_with("[..]")
-}
-
-#[test]
-fn lines_match_works() {
-    assert!(lines_match("a b", "a b"));
-    assert!(lines_match("a[..]b", "a b"));
-    assert!(lines_match("a[..]", "a b"));
-    assert!(lines_match("[..]", "a b"));
-    assert!(lines_match("[..]b", "a b"));
-
-    assert!(!lines_match("[..]b", "c"));
-    assert!(!lines_match("b", "c"));
-    assert!(!lines_match("b", "cb"));
-}
-
-/// Compares JSON object for approximate equality.
-/// You can use `[..]` wildcard in strings (useful for OS dependent things such
-/// as paths). You can use a `"{...}"` string literal as a wildcard for
-/// arbitrary nested JSON. Arrays are sorted before comparison.
-pub fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a Value, &'a Value)> {
-    match (expected, actual) {
-        (Value::Number(l), Value::Number(r)) if l == r => None,
-        (Value::Bool(l), Value::Bool(r)) if l == r => None,
-        (Value::String(l), Value::String(r)) if lines_match(l, r) => None,
-        (Value::Array(l), Value::Array(r)) => {
-            if l.len() != r.len() {
-                return Some((expected, actual));
-            }
-
-            let mut l = l.iter().collect::<Vec<_>>();
-            let mut r = r.iter().collect::<Vec<_>>();
-
-            l.retain(|l| match r.iter().position(|r| find_mismatch(l, r).is_none()) {
-                Some(i) => {
-                    r.remove(i);
-                    false
-                }
-                None => true,
-            });
-
-            if !l.is_empty() {
-                assert!(!r.is_empty());
-                Some((&l[0], &r[0]))
-            } else {
-                assert_eq!(r.len(), 0);
-                None
-            }
-        }
-        (Value::Object(l), Value::Object(r)) => {
-            fn sorted_values(obj: &serde_json::Map<String, Value>) -> Vec<&Value> {
-                let mut entries = obj.iter().collect::<Vec<_>>();
-                entries.sort_by_key(|it| it.0);
-                entries.into_iter().map(|(_k, v)| v).collect::<Vec<_>>()
-            }
-
-            let same_keys = l.len() == r.len() && l.keys().all(|k| r.contains_key(k));
-            if !same_keys {
-                return Some((expected, actual));
-            }
-
-            let l = sorted_values(l);
-            let r = sorted_values(r);
-
-            l.into_iter().zip(r).filter_map(|(l, r)| find_mismatch(l, r)).next()
-        }
-        (Value::Null, Value::Null) => None,
-        // magic string literal "{...}" acts as wildcard for any sub-JSON
-        (Value::String(l), _) if l == "{...}" => None,
-        _ => Some((expected, actual)),
-    }
-}
-
 /// Returns `false` if slow tests should not run, otherwise returns `true` and
 /// also creates a file at `./target/.slow_tests_cookie` which serves as a flag
 /// that slow tests did run.
@@ -384,14 +286,14 @@ pub fn skip_slow_tests() -> bool {
     if should_skip {
         eprintln!("ignoring slow test")
     } else {
-        let path = project_dir().join("./target/.slow_tests_cookie");
+        let path = project_root().join("./target/.slow_tests_cookie");
         fs::write(&path, ".").unwrap();
     }
     should_skip
 }
 
 /// Returns the path to the root directory of `rust-analyzer` project.
-pub fn project_dir() -> PathBuf {
+pub fn project_root() -> PathBuf {
     let dir = env!("CARGO_MANIFEST_DIR");
     PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
 }
@@ -449,3 +351,39 @@ pub fn bench(label: &'static str) -> impl Drop {
 
     Bencher { sw: StopWatch::start(), label }
 }
+
+/// Checks that the `file` has the specified `contents`. If that is not the
+/// case, updates the file and then fails the test.
+pub fn ensure_file_contents(file: &Path, contents: &str) {
+    if let Err(()) = try_ensure_file_contents(file, contents) {
+        panic!("Some files were not up-to-date");
+    }
+}
+
+/// Checks that the `file` has the specified `contents`. If that is not the
+/// case, updates the file and return an Error.
+pub fn try_ensure_file_contents(file: &Path, contents: &str) -> Result<(), ()> {
+    match std::fs::read_to_string(file) {
+        Ok(old_contents) if normalize_newlines(&old_contents) == normalize_newlines(contents) => {
+            return Ok(())
+        }
+        _ => (),
+    }
+    let display_path = file.strip_prefix(&project_root()).unwrap_or(file);
+    eprintln!(
+        "\n\x1b[31;1merror\x1b[0m: {} was not up-to-date, updating\n",
+        display_path.display()
+    );
+    if is_ci() {
+        eprintln!("    NOTE: run `cargo test` locally and commit the updated files\n");
+    }
+    if let Some(parent) = file.parent() {
+        let _ = std::fs::create_dir_all(parent);
+    }
+    std::fs::write(file, contents).unwrap();
+    Err(())
+}
+
+fn normalize_newlines(s: &str) -> String {
+    s.replace("\r\n", "\n")
+}
diff --git a/crates/test_utils/src/mark.rs b/crates/test_utils/src/mark.rs
deleted file mode 100644
index 97f5a93ad..000000000
--- a/crates/test_utils/src/mark.rs
+++ /dev/null
@@ -1,78 +0,0 @@
-//! This module implements manually tracked test coverage, which is useful for
-//! quickly finding a test responsible for testing a particular bit of code.
-//!
-//! See <https://matklad.github.io/2018/06/18/a-trick-for-test-maintenance.html>
-//! for details, but the TL;DR is that you write your test as
-//!
-//! ```
-//! #[test]
-//! fn test_foo() {
-//!     mark::check!(test_foo);
-//! }
-//! ```
-//!
-//! and in the code under test you write
-//!
-//! ```
-//! # use test_utils::mark;
-//! # fn some_condition() -> bool { true }
-//! fn foo() {
-//!     if some_condition() {
-//!         mark::hit!(test_foo);
-//!     }
-//! }
-//! ```
-//!
-//! This module then checks that executing the test indeed covers the specified
-//! function. This is useful if you come back to the `foo` function ten years
-//! later and wonder where the test are: now you can grep for `test_foo`.
-use std::sync::atomic::{AtomicUsize, Ordering};
-
-#[macro_export]
-macro_rules! _hit {
-    ($ident:ident) => {{
-        #[cfg(test)]
-        {
-            extern "C" {
-                #[no_mangle]
-                static $ident: std::sync::atomic::AtomicUsize;
-            }
-            unsafe {
-                $ident.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
-            }
-        }
-    }};
-}
-pub use _hit as hit;
-
-#[macro_export]
-macro_rules! _check {
-    ($ident:ident) => {
-        #[no_mangle]
-        static $ident: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
-        let _checker = $crate::mark::MarkChecker::new(&$ident);
-    };
-}
-pub use _check as check;
-
-pub struct MarkChecker {
-    mark: &'static AtomicUsize,
-    value_on_entry: usize,
-}
-
-impl MarkChecker {
-    pub fn new(mark: &'static AtomicUsize) -> MarkChecker {
-        let value_on_entry = mark.load(Ordering::Relaxed);
-        MarkChecker { mark, value_on_entry }
-    }
-}
-
-impl Drop for MarkChecker {
-    fn drop(&mut self) {
-        if std::thread::panicking() {
-            return;
-        }
-        let value_on_exit = self.mark.load(Ordering::Relaxed);
-        assert!(value_on_exit > self.value_on_entry, "mark was not hit")
-    }
-}