18 files changed, 748 insertions, 294 deletions

diff --git a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
index 40028fc01..e3ef04932 100644
--- a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -2,12 +2,16 @@ use std::iter;
 
 use either::Either;
 use hir::{AsName, Module, ModuleDef, Name, Variant};
-use ide_db::helpers::{
-    insert_use::{insert_use, ImportScope},
-    mod_path_to_ast,
+use ide_db::{
+    defs::Definition,
+    helpers::{
+        insert_use::{insert_use, ImportScope},
+        mod_path_to_ast,
+    },
+    search::FileReference,
+    RootDatabase,
 };
-use ide_db::{defs::Definition, search::Reference, RootDatabase};
-use rustc_hash::{FxHashMap, FxHashSet};
+use rustc_hash::FxHashSet;
 use syntax::{
     algo::{find_node_at_offset, SyntaxRewriter},
     ast::{self, edit::IndentLevel, make, AstNode, NameOwner, VisibilityOwner},
@@ -58,29 +62,29 @@ pub(crate) fn extract_struct_from_enum_variant(
             let mut visited_modules_set = FxHashSet::default();
             let current_module = enum_hir.module(ctx.db());
             visited_modules_set.insert(current_module);
-            let mut rewriters = FxHashMap::default();
-            for reference in usages {
-                let rewriter = rewriters
-                    .entry(reference.file_range.file_id)
-                    .or_insert_with(SyntaxRewriter::default);
-                let source_file = ctx.sema.parse(reference.file_range.file_id);
-                update_reference(
-                    ctx,
-                    rewriter,
-                    reference,
-                    &source_file,
-                    &enum_module_def,
-                    &variant_hir_name,
-                    &mut visited_modules_set,
-                );
-            }
-            let mut rewriter =
-                rewriters.remove(&ctx.frange.file_id).unwrap_or_else(SyntaxRewriter::default);
-            for (file_id, rewriter) in rewriters {
+            let mut def_rewriter = None;
+            for (file_id, references) in usages {
+                let mut rewriter = SyntaxRewriter::default();
+                let source_file = ctx.sema.parse(file_id);
+                for reference in references {
+                    update_reference(
+                        ctx,
+                        &mut rewriter,
+                        reference,
+                        &source_file,
+                        &enum_module_def,
+                        &variant_hir_name,
+                        &mut visited_modules_set,
+                    );
+                }
+                if file_id == ctx.frange.file_id {
+                    def_rewriter = Some(rewriter);
+                    continue;
+                }
                 builder.edit_file(file_id);
                 builder.rewrite(rewriter);
             }
-            builder.edit_file(ctx.frange.file_id);
+            let mut rewriter = def_rewriter.unwrap_or_default();
             update_variant(&mut rewriter, &variant);
             extract_struct_def(
                 &mut rewriter,
@@ -90,6 +94,7 @@ pub(crate) fn extract_struct_from_enum_variant(
                 &variant.parent_enum().syntax().clone().into(),
                 enum_ast.visibility(),
             );
+            builder.edit_file(ctx.frange.file_id);
             builder.rewrite(rewriter);
         },
     )
@@ -205,13 +210,13 @@ fn update_variant(rewriter: &mut SyntaxRewriter, variant: &ast::Variant) -> Opti
 fn update_reference(
     ctx: &AssistContext,
     rewriter: &mut SyntaxRewriter,
-    reference: Reference,
+    reference: FileReference,
     source_file: &SourceFile,
     enum_module_def: &ModuleDef,
     variant_hir_name: &Name,
     visited_modules_set: &mut FxHashSet<Module>,
 ) -> Option<()> {
-    let offset = reference.file_range.range.start();
+    let offset = reference.range.start();
     let (segment, expr) = if let Some(path_expr) =
         find_node_at_offset::<ast::PathExpr>(source_file.syntax(), offset)
     {
diff --git a/crates/assists/src/handlers/inline_local_variable.rs b/crates/assists/src/handlers/inline_local_variable.rs
index d559be9cb..dc798daaa 100644
--- a/crates/assists/src/handlers/inline_local_variable.rs
+++ b/crates/assists/src/handlers/inline_local_variable.rs
@@ -1,4 +1,7 @@
-use ide_db::{defs::Definition, search::ReferenceKind};
+use ide_db::{
+    defs::Definition,
+    search::{FileReference, ReferenceKind},
+};
 use syntax::{
     ast::{self, AstNode, AstToken},
     TextRange,
@@ -44,8 +47,8 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
 
     let def = ctx.sema.to_def(&bind_pat)?;
     let def = Definition::Local(def);
-    let refs = def.usages(&ctx.sema).all();
-    if refs.is_empty() {
+    let usages = def.usages(&ctx.sema).all();
+    if usages.is_empty() {
         mark::hit!(test_not_applicable_if_variable_unused);
         return None;
     };
@@ -63,48 +66,45 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
         let_stmt.syntax().text_range()
     };
 
-    let mut wrap_in_parens = vec![true; refs.len()];
-
-    for (i, desc) in refs.iter().enumerate() {
-        let usage_node = ctx
-            .covering_node_for_range(desc.file_range.range)
-            .ancestors()
-            .find_map(ast::PathExpr::cast)?;
-        let usage_parent_option = usage_node.syntax().parent().and_then(ast::Expr::cast);
-        let usage_parent = match usage_parent_option {
-            Some(u) => u,
-            None => {
-                wrap_in_parens[i] = false;
-                continue;
-            }
-        };
-
-        wrap_in_parens[i] = match (&initializer_expr, usage_parent) {
-            (ast::Expr::CallExpr(_), _)
-            | (ast::Expr::IndexExpr(_), _)
-            | (ast::Expr::MethodCallExpr(_), _)
-            | (ast::Expr::FieldExpr(_), _)
-            | (ast::Expr::TryExpr(_), _)
-            | (ast::Expr::RefExpr(_), _)
-            | (ast::Expr::Literal(_), _)
-            | (ast::Expr::TupleExpr(_), _)
-            | (ast::Expr::ArrayExpr(_), _)
-            | (ast::Expr::ParenExpr(_), _)
-            | (ast::Expr::PathExpr(_), _)
-            | (ast::Expr::BlockExpr(_), _)
-            | (ast::Expr::EffectExpr(_), _)
-            | (_, ast::Expr::CallExpr(_))
-            | (_, ast::Expr::TupleExpr(_))
-            | (_, ast::Expr::ArrayExpr(_))
-            | (_, ast::Expr::ParenExpr(_))
-            | (_, ast::Expr::ForExpr(_))
-            | (_, ast::Expr::WhileExpr(_))
-            | (_, ast::Expr::BreakExpr(_))
-            | (_, ast::Expr::ReturnExpr(_))
-            | (_, ast::Expr::MatchExpr(_)) => false,
-            _ => true,
-        };
-    }
+    let wrap_in_parens = usages
+        .references
+        .values()
+        .flatten()
+        .map(|&FileReference { range, .. }| {
+            let usage_node =
+                ctx.covering_node_for_range(range).ancestors().find_map(ast::PathExpr::cast)?;
+            let usage_parent_option = usage_node.syntax().parent().and_then(ast::Expr::cast);
+            let usage_parent = match usage_parent_option {
+                Some(u) => u,
+                None => return Ok(false),
+            };
+
+            Ok(!matches!((&initializer_expr, usage_parent),
+                (ast::Expr::CallExpr(_), _)
+                | (ast::Expr::IndexExpr(_), _)
+                | (ast::Expr::MethodCallExpr(_), _)
+                | (ast::Expr::FieldExpr(_), _)
+                | (ast::Expr::TryExpr(_), _)
+                | (ast::Expr::RefExpr(_), _)
+                | (ast::Expr::Literal(_), _)
+                | (ast::Expr::TupleExpr(_), _)
+                | (ast::Expr::ArrayExpr(_), _)
+                | (ast::Expr::ParenExpr(_), _)
+                | (ast::Expr::PathExpr(_), _)
+                | (ast::Expr::BlockExpr(_), _)
+                | (ast::Expr::EffectExpr(_), _)
+                | (_, ast::Expr::CallExpr(_))
+                | (_, ast::Expr::TupleExpr(_))
+                | (_, ast::Expr::ArrayExpr(_))
+                | (_, ast::Expr::ParenExpr(_))
+                | (_, ast::Expr::ForExpr(_))
+                | (_, ast::Expr::WhileExpr(_))
+                | (_, ast::Expr::BreakExpr(_))
+                | (_, ast::Expr::ReturnExpr(_))
+                | (_, ast::Expr::MatchExpr(_))
+            ))
+        })
+        .collect::<Result<Vec<_>, _>>()?;
 
     let init_str = initializer_expr.syntax().text().to_string();
     let init_in_paren = format!("({})", &init_str);
@@ -116,15 +116,16 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
         target,
         move |builder| {
             builder.delete(delete_range);
-            for (desc, should_wrap) in refs.iter().zip(wrap_in_parens) {
+            for (reference, should_wrap) in usages.references.values().flatten().zip(wrap_in_parens)
+            {
                 let replacement =
                     if should_wrap { init_in_paren.clone() } else { init_str.clone() };
-                match desc.kind {
+                match reference.kind {
                     ReferenceKind::FieldShorthandForLocal => {
                         mark::hit!(inline_field_shorthand);
-                        builder.insert(desc.file_range.range.end(), format!(": {}", replacement))
+                        builder.insert(reference.range.end(), format!(": {}", replacement))
                     }
-                    _ => builder.replace(desc.file_range.range, replacement),
+                    _ => builder.replace(reference.range, replacement),
                 }
             }
         },
diff --git a/crates/assists/src/handlers/remove_unused_param.rs b/crates/assists/src/handlers/remove_unused_param.rs
index 56e8b5229..c961680e2 100644
--- a/crates/assists/src/handlers/remove_unused_param.rs
+++ b/crates/assists/src/handlers/remove_unused_param.rs
@@ -1,8 +1,8 @@
-use ide_db::{defs::Definition, search::Reference};
+use ide_db::{base_db::FileId, defs::Definition, search::FileReference};
 use syntax::{
     algo::find_node_at_range,
     ast::{self, ArgListOwner},
-    AstNode, SyntaxKind, SyntaxNode, TextRange, T,
+    AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange, T,
 };
 use test_utils::mark;
 use SyntaxKind::WHITESPACE;
@@ -58,32 +58,41 @@ pub(crate) fn remove_unused_param(acc: &mut Assists, ctx: &AssistContext) -> Opt
         param.syntax().text_range(),
         |builder| {
             builder.delete(range_to_remove(param.syntax()));
-            for usage in fn_def.usages(&ctx.sema).all() {
-                process_usage(ctx, builder, usage, param_position);
+            for (file_id, references) in fn_def.usages(&ctx.sema).all() {
+                process_usages(ctx, builder, file_id, references, param_position);
             }
         },
     )
 }
 
-fn process_usage(
+fn process_usages(
     ctx: &AssistContext,
     builder: &mut AssistBuilder,
-    usage: Reference,
+    file_id: FileId,
+    references: Vec<FileReference>,
     arg_to_remove: usize,
-) -> Option<()> {
-    let source_file = ctx.sema.parse(usage.file_range.file_id);
-    let call_expr: ast::CallExpr =
-        find_node_at_range(source_file.syntax(), usage.file_range.range)?;
+) {
+    let source_file = ctx.sema.parse(file_id);
+    builder.edit_file(file_id);
+    for usage in references {
+        if let Some(text_range) = process_usage(&source_file, usage, arg_to_remove) {
+            builder.delete(text_range);
+        }
+    }
+}
+
+fn process_usage(
+    source_file: &SourceFile,
+    FileReference { range, .. }: FileReference,
+    arg_to_remove: usize,
+) -> Option<TextRange> {
+    let call_expr: ast::CallExpr = find_node_at_range(source_file.syntax(), range)?;
     let call_expr_range = call_expr.expr()?.syntax().text_range();
-    if !call_expr_range.contains_range(usage.file_range.range) {
+    if !call_expr_range.contains_range(range) {
         return None;
     }
     let arg = call_expr.arg_list()?.args().nth(arg_to_remove)?;
-
-    builder.edit_file(usage.file_range.file_id);
-    builder.delete(range_to_remove(arg.syntax()));
-
-    Some(())
+    Some(range_to_remove(arg.syntax()))
 }
 
 fn range_to_remove(node: &SyntaxNode) -> TextRange {
diff --git a/crates/assists/src/handlers/reorder_impl.rs b/crates/assists/src/handlers/reorder_impl.rs
new file mode 100644
index 000000000..309f291c8
--- /dev/null
+++ b/crates/assists/src/handlers/reorder_impl.rs
@@ -0,0 +1,201 @@
+use itertools::Itertools;
+use rustc_hash::FxHashMap;
+
+use hir::{PathResolution, Semantics};
+use ide_db::RootDatabase;
+use syntax::{
+    algo,
+    ast::{self, NameOwner},
+    AstNode,
+};
+use test_utils::mark;
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: reorder_impl
+//
+// Reorder the methods of an `impl Trait`. The methods will be ordered
+// in the same order as in the trait definition.
+//
+// ```
+// trait Foo {
+//     fn a() {}
+//     fn b() {}
+//     fn c() {}
+// }
+//
+// struct Bar;
+// $0impl Foo for Bar {
+//     fn b() {}
+//     fn c() {}
+//     fn a() {}
+// }
+// ```
+// ->
+// ```
+// trait Foo {
+//     fn a() {}
+//     fn b() {}
+//     fn c() {}
+// }
+//
+// struct Bar;
+// impl Foo for Bar {
+//     fn a() {}
+//     fn b() {}
+//     fn c() {}
+// }
+// ```
+//
+pub(crate) fn reorder_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let impl_ast = ctx.find_node_at_offset::<ast::Impl>()?;
+    let items = impl_ast.assoc_item_list()?;
+    let methods = get_methods(&items);
+
+    let path = impl_ast
+        .trait_()
+        .and_then(|t| match t {
+            ast::Type::PathType(path) => Some(path),
+            _ => None,
+        })?
+        .path()?;
+
+    let ranks = compute_method_ranks(&path, ctx)?;
+    let sorted: Vec<_> = methods
+        .iter()
+        .cloned()
+        .sorted_by_key(|f| {
+            f.name().and_then(|n| ranks.get(&n.to_string()).copied()).unwrap_or(usize::max_value())
+        })
+        .collect();
+
+    // Don't edit already sorted methods:
+    if methods == sorted {
+        mark::hit!(not_applicable_if_sorted);
+        return None;
+    }
+
+    let target = items.syntax().text_range();
+    acc.add(AssistId("reorder_impl", AssistKind::RefactorRewrite), "Sort methods", target, |edit| {
+        let mut rewriter = algo::SyntaxRewriter::default();
+        for (old, new) in methods.iter().zip(&sorted) {
+            rewriter.replace(old.syntax(), new.syntax());
+        }
+        edit.rewrite(rewriter);
+    })
+}
+
+fn compute_method_ranks(path: &ast::Path, ctx: &AssistContext) -> Option<FxHashMap<String, usize>> {
+    let td = trait_definition(path, &ctx.sema)?;
+
+    Some(
+        td.items(ctx.db())
+            .iter()
+            .flat_map(|i| match i {
+                hir::AssocItem::Function(f) => Some(f),
+                _ => None,
+            })
+            .enumerate()
+            .map(|(idx, func)| ((func.name(ctx.db()).to_string(), idx)))
+            .collect(),
+    )
+}
+
+fn trait_definition(path: &ast::Path, sema: &Semantics<RootDatabase>) -> Option<hir::Trait> {
+    match sema.resolve_path(path)? {
+        PathResolution::Def(hir::ModuleDef::Trait(trait_)) => Some(trait_),
+        _ => None,
+    }
+}
+
+fn get_methods(items: &ast::AssocItemList) -> Vec<ast::Fn> {
+    items
+        .assoc_items()
+        .flat_map(|i| match i {
+            ast::AssocItem::Fn(f) => Some(f),
+            _ => None,
+        })
+        .filter(|f| f.name().is_some())
+        .collect()
+}
+
+#[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);
+        check_assist_not_applicable(
+            reorder_impl,
+            r#"
+trait Bar {
+    fn a() {}
+    fn z() {}
+    fn b() {}
+}
+struct Foo;
+$0impl Bar for Foo {
+    fn a() {}
+    fn z() {}
+    fn b() {}
+}
+        "#,
+        )
+    }
+
+    #[test]
+    fn not_applicable_if_empty() {
+        check_assist_not_applicable(
+            reorder_impl,
+            r#"
+trait Bar {};
+struct Foo;
+$0impl Bar for Foo {}
+        "#,
+        )
+    }
+
+    #[test]
+    fn reorder_impl_trait_methods() {
+        check_assist(
+            reorder_impl,
+            r#"
+trait Bar {
+    fn a() {}
+    fn c() {}
+    fn b() {}
+    fn d() {}
+}
+
+struct Foo;
+$0impl Bar for Foo {
+    fn d() {}
+    fn b() {}
+    fn c() {}
+    fn a() {}
+}
+        "#,
+            r#"
+trait Bar {
+    fn a() {}
+    fn c() {}
+    fn b() {}
+    fn d() {}
+}
+
+struct Foo;
+impl Bar for Foo {
+    fn a() {}
+    fn c() {}
+    fn b() {}
+    fn d() {}
+}
+        "#,
+        )
+    }
+}
diff --git a/crates/assists/src/lib.rs b/crates/assists/src/lib.rs
index 90009c55a..1080294ab 100644
--- a/crates/assists/src/lib.rs
+++ b/crates/assists/src/lib.rs
@@ -146,6 +146,7 @@ mod handlers {
     mod remove_mut;
     mod remove_unused_param;
     mod reorder_fields;
+    mod reorder_impl;
     mod replace_derive_with_manual_impl;
     mod replace_if_let_with_match;
     mod replace_impl_trait_with_generic;
@@ -202,6 +203,7 @@ mod handlers {
             remove_mut::remove_mut,
             remove_unused_param::remove_unused_param,
             reorder_fields::reorder_fields,
+            reorder_impl::reorder_impl,
             replace_derive_with_manual_impl::replace_derive_with_manual_impl,
             replace_if_let_with_match::replace_if_let_with_match,
             replace_if_let_with_match::replace_match_with_if_let,
diff --git a/crates/assists/src/tests/generated.rs b/crates/assists/src/tests/generated.rs
index e28837b53..217f577eb 100644
--- a/crates/assists/src/tests/generated.rs
+++ b/crates/assists/src/tests/generated.rs
@@ -896,6 +896,41 @@ const test: Foo = Foo {foo: 1, bar: 0}
 }
 
 #[test]
+fn doctest_reorder_impl() {
+    check_doc_test(
+        "reorder_impl",
+        r#####"
+trait Foo {
+    fn a() {}
+    fn b() {}
+    fn c() {}
+}
+
+struct Bar;
+$0impl Foo for Bar {
+    fn b() {}
+    fn c() {}
+    fn a() {}
+}
+"#####,
+        r#####"
+trait Foo {
+    fn a() {}
+    fn b() {}
+    fn c() {}
+}
+
+struct Bar;
+impl Foo for Bar {
+    fn a() {}
+    fn b() {}
+    fn c() {}
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_replace_derive_with_manual_impl() {
     check_doc_test(
         "replace_derive_with_manual_impl",
diff --git a/crates/ide/src/call_hierarchy.rs b/crates/ide/src/call_hierarchy.rs
index b29d1fef9..e8999a7f3 100644
--- a/crates/ide/src/call_hierarchy.rs
+++ b/crates/ide/src/call_hierarchy.rs
@@ -47,22 +47,23 @@ pub(crate) fn incoming_calls(db: &RootDatabase, position: FilePosition) -> Optio
 
     let mut calls = CallLocations::default();
 
-    for reference in refs.info.references() {
-        let file_id = reference.file_range.file_id;
+    for (&file_id, references) in refs.info.references().iter() {
         let file = sema.parse(file_id);
         let file = file.syntax();
-        let token = file.token_at_offset(reference.file_range.range.start()).next()?;
-        let token = sema.descend_into_macros(token);
-        let syntax = token.parent();
-
-        // This target is the containing function
-        if let Some(nav) = syntax.ancestors().find_map(|node| {
-            let fn_ = ast::Fn::cast(node)?;
-            let def = sema.to_def(&fn_)?;
-            def.try_to_nav(sema.db)
-        }) {
-            let relative_range = reference.file_range.range;
-            calls.add(&nav, relative_range);
+        for reference in references {
+            let token = file.token_at_offset(reference.range.start()).next()?;
+            let token = sema.descend_into_macros(token);
+            let syntax = token.parent();
+
+            // This target is the containing function
+            if let Some(nav) = syntax.ancestors().find_map(|node| {
+                let fn_ = ast::Fn::cast(node)?;
+                let def = sema.to_def(&fn_)?;
+                def.try_to_nav(sema.db)
+            }) {
+                let relative_range = reference.range;
+                calls.add(&nav, relative_range);
+            }
         }
     }
 
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 1f368cbd0..1e03832ec 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -92,7 +92,7 @@ pub use ide_db::base_db::{
 };
 pub use ide_db::{
     call_info::CallInfo,
-    search::{Reference, ReferenceAccess, ReferenceKind},
+    search::{FileReference, ReferenceAccess, ReferenceKind},
 };
 pub use ide_db::{
     label::Label,
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index b774a2be1..7d4757e02 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -13,9 +13,9 @@ pub(crate) mod rename;
 
 use hir::Semantics;
 use ide_db::{
+    base_db::FileId,
     defs::{Definition, NameClass, NameRefClass},
-    search::Reference,
-    search::{ReferenceAccess, ReferenceKind, SearchScope},
+    search::{FileReference, ReferenceAccess, ReferenceKind, SearchScope, UsageSearchResult},
     RootDatabase,
 };
 use syntax::{
@@ -29,7 +29,7 @@ use crate::{display::TryToNav, FilePosition, FileRange, NavigationTarget, RangeI
 #[derive(Debug, Clone)]
 pub struct ReferenceSearchResult {
     declaration: Declaration,
-    references: Vec<Reference>,
+    references: UsageSearchResult,
 }
 
 #[derive(Debug, Clone)]
@@ -48,10 +48,21 @@ impl ReferenceSearchResult {
         &self.declaration.nav
     }
 
-    pub fn references(&self) -> &[Reference] {
+    pub fn references(&self) -> &UsageSearchResult {
         &self.references
     }
 
+    pub fn references_with_declaration(mut self) -> UsageSearchResult {
+        let decl_ref = FileReference {
+            range: self.declaration.nav.focus_or_full_range(),
+            kind: self.declaration.kind,
+            access: self.declaration.access,
+        };
+        let file_id = self.declaration.nav.file_id;
+        self.references.references.entry(file_id).or_default().push(decl_ref);
+        self.references
+    }
+
     /// Total number of references
     /// At least 1 since all valid references should
     /// Have a declaration
@@ -63,21 +74,11 @@ impl ReferenceSearchResult {
 // allow turning ReferenceSearchResult into an iterator
 // over References
 impl IntoIterator for ReferenceSearchResult {
-    type Item = Reference;
-    type IntoIter = std::vec::IntoIter<Reference>;
-
-    fn into_iter(mut self) -> Self::IntoIter {
-        let mut v = Vec::with_capacity(self.len());
-        v.push(Reference {
-            file_range: FileRange {
-                file_id: self.declaration.nav.file_id,
-                range: self.declaration.nav.focus_or_full_range(),
-            },
-            kind: self.declaration.kind,
-            access: self.declaration.access,
-        });
-        v.append(&mut self.references);
-        v.into_iter()
+    type Item = (FileId, Vec<FileReference>);
+    type IntoIter = std::collections::hash_map::IntoIter<FileId, Vec<FileReference>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.references_with_declaration().into_iter()
     }
 }
 
@@ -109,13 +110,12 @@ pub(crate) fn find_all_refs(
 
     let RangeInfo { range, info: def } = find_name(&sema, &syntax, position, opt_name)?;
 
-    let references = def
-        .usages(sema)
-        .set_scope(search_scope)
-        .all()
-        .into_iter()
-        .filter(|r| search_kind == ReferenceKind::Other || search_kind == r.kind)
-        .collect();
+    let mut usages = def.usages(sema).set_scope(search_scope).all();
+    usages
+        .references
+        .values_mut()
+        .for_each(|it| it.retain(|r| search_kind == ReferenceKind::Other || search_kind == r.kind));
+    usages.references.retain(|_, it| !it.is_empty());
 
     let nav = def.try_to_nav(sema.db)?;
     let decl_range = nav.focus_or_full_range();
@@ -139,7 +139,7 @@ pub(crate) fn find_all_refs(
 
     let declaration = Declaration { nav, kind, access: decl_access(&def, &syntax, decl_range) };
 
-    Some(RangeInfo::new(range, ReferenceSearchResult { declaration, references }))
+    Some(RangeInfo::new(range, ReferenceSearchResult { declaration, references: usages }))
 }
 
 fn find_name(
@@ -255,7 +255,8 @@ fn try_find_self_references(
     syntax: &SyntaxNode,
     position: FilePosition,
 ) -> Option<RangeInfo<ReferenceSearchResult>> {
-    let self_token = syntax.token_at_offset(position.offset).find(|t| t.kind() == T![self])?;
+    let FilePosition { file_id, offset } = position;
+    let self_token = syntax.token_at_offset(offset).find(|t| t.kind() == T![self])?;
     let parent = self_token.parent();
     match_ast! {
         match parent {
@@ -276,7 +277,7 @@ fn try_find_self_references(
 
     let declaration = Declaration {
         nav: NavigationTarget {
-            file_id: position.file_id,
+            file_id,
             full_range: self_param.syntax().text_range(),
             focus_range: Some(param_self_token.text_range()),
             name: param_self_token.text().clone(),
@@ -292,7 +293,7 @@ fn try_find_self_references(
             ReferenceAccess::Read
         }),
     };
-    let references = function
+    let refs = function
         .body()
         .map(|body| {
             body.syntax()
@@ -306,14 +307,16 @@ fn try_find_self_references(
                         None
                     }
                 })
-                .map(|token| Reference {
-                    file_range: FileRange { file_id: position.file_id, range: token.text_range() },
+                .map(|token| FileReference {
+                    range: token.text_range(),
                     kind: ReferenceKind::SelfKw,
                     access: declaration.access, // FIXME: properly check access kind here instead of copying it from the declaration
                 })
                 .collect()
         })
         .unwrap_or_default();
+    let mut references = UsageSearchResult::default();
+    references.references.insert(file_id, refs);
 
     Some(RangeInfo::new(
         param_self_token.text_range(),
@@ -1018,12 +1021,14 @@ impl Foo {
             actual += "\n\n";
         }
 
-        for r in &refs.references {
-            format_to!(actual, "{:?} {:?} {:?}", r.file_range.file_id, r.file_range.range, r.kind);
-            if let Some(access) = r.access {
-                format_to!(actual, " {:?}", access);
+        for (file_id, references) in refs.references {
+            for r in references {
+                format_to!(actual, "{:?} {:?} {:?}", file_id, r.range, r.kind);
+                if let Some(access) = r.access {
+                    format_to!(actual, " {:?}", access);
+                }
+                actual += "\n";
             }
-            actual += "\n";
         }
         expect.assert_eq(&actual)
     }
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 3edc43e08..c3ae568c2 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -1,14 +1,14 @@
 //! FIXME: write short doc here
 use std::{
     convert::TryInto,
-    error::Error,
     fmt::{self, Display},
 };
 
 use hir::{Module, ModuleDef, ModuleSource, Semantics};
-use ide_db::base_db::{AnchoredPathBuf, FileId, FileRange, SourceDatabaseExt};
 use ide_db::{
+    base_db::{AnchoredPathBuf, FileId, FileRange, SourceDatabaseExt},
     defs::{Definition, NameClass, NameRefClass},
+    search::FileReference,
     RootDatabase,
 };
 use syntax::{
@@ -20,8 +20,8 @@ use test_utils::mark;
 use text_edit::TextEdit;
 
 use crate::{
-    FilePosition, FileSystemEdit, RangeInfo, Reference, ReferenceKind, ReferenceSearchResult,
-    SourceChange, SourceFileEdit, TextRange, TextSize,
+    FilePosition, FileSystemEdit, RangeInfo, ReferenceKind, ReferenceSearchResult, SourceChange,
+    SourceFileEdit, TextRange, TextSize,
 };
 
 type RenameResult<T> = Result<T, RenameError>;
@@ -34,8 +34,6 @@ impl fmt::Display for RenameError {
     }
 }
 
-impl Error for RenameError {}
-
 macro_rules! format_err {
     ($fmt:expr) => {RenameError(format!($fmt))};
     ($fmt:expr, $($arg:tt)+) => {RenameError(format!($fmt, $($arg)+))}
@@ -173,39 +171,46 @@ fn find_all_refs(
         .ok_or_else(|| format_err!("No references found at position"))
 }
 
-fn source_edit_from_reference(
+fn source_edit_from_references(
     sema: &Semantics<RootDatabase>,
-    reference: Reference,
+    file_id: FileId,
+    references: &[FileReference],
     new_name: &str,
 ) -> SourceFileEdit {
-    let mut replacement_text = String::new();
-    let range = match reference.kind {
-        ReferenceKind::FieldShorthandForField => {
-            mark::hit!(test_rename_struct_field_for_shorthand);
-            replacement_text.push_str(new_name);
-            replacement_text.push_str(": ");
-            TextRange::new(reference.file_range.range.start(), reference.file_range.range.start())
-        }
-        ReferenceKind::FieldShorthandForLocal => {
-            mark::hit!(test_rename_local_for_field_shorthand);
-            replacement_text.push_str(": ");
-            replacement_text.push_str(new_name);
-            TextRange::new(reference.file_range.range.end(), reference.file_range.range.end())
-        }
-        ReferenceKind::RecordFieldExprOrPat => {
-            mark::hit!(test_rename_field_expr_pat);
-            replacement_text.push_str(new_name);
-            edit_text_range_for_record_field_expr_or_pat(sema, reference.file_range, new_name)
-        }
-        _ => {
-            replacement_text.push_str(new_name);
-            reference.file_range.range
-        }
-    };
-    SourceFileEdit {
-        file_id: reference.file_range.file_id,
-        edit: TextEdit::replace(range, replacement_text),
+    let mut edit = TextEdit::builder();
+    for reference in references {
+        let mut replacement_text = String::new();
+        let range = match reference.kind {
+            ReferenceKind::FieldShorthandForField => {
+                mark::hit!(test_rename_struct_field_for_shorthand);
+                replacement_text.push_str(new_name);
+                replacement_text.push_str(": ");
+                TextRange::new(reference.range.start(), reference.range.start())
+            }
+            ReferenceKind::FieldShorthandForLocal => {
+                mark::hit!(test_rename_local_for_field_shorthand);
+                replacement_text.push_str(": ");
+                replacement_text.push_str(new_name);
+                TextRange::new(reference.range.end(), reference.range.end())
+            }
+            ReferenceKind::RecordFieldExprOrPat => {
+                mark::hit!(test_rename_field_expr_pat);
+                replacement_text.push_str(new_name);
+                edit_text_range_for_record_field_expr_or_pat(
+                    sema,
+                    FileRange { file_id, range: reference.range },
+                    new_name,
+                )
+            }
+            _ => {
+                replacement_text.push_str(new_name);
+                reference.range
+            }
+        };
+        edit.replace(range, replacement_text);
     }
+
+    SourceFileEdit { file_id, edit: edit.finish() }
 }
 
 fn edit_text_range_for_record_field_expr_or_pat(
@@ -276,10 +281,9 @@ fn rename_mod(
     }
 
     let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
-    let ref_edits = refs
-        .references
-        .into_iter()
-        .map(|reference| source_edit_from_reference(sema, reference, new_name));
+    let ref_edits = refs.references().iter().map(|(&file_id, references)| {
+        source_edit_from_references(sema, file_id, references, new_name)
+    });
     source_file_edits.extend(ref_edits);
 
     Ok(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
@@ -331,17 +335,12 @@ fn rename_to_self(
 
     let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
 
-    let (param_ref, usages): (Vec<Reference>, Vec<Reference>) = refs
-        .into_iter()
-        .partition(|reference| param_range.intersect(reference.file_range.range).is_some());
-
-    if param_ref.is_empty() {
-        bail!("Parameter to rename not found");
-    }
-
-    let mut edits = usages
-        .into_iter()
-        .map(|reference| source_edit_from_reference(sema, reference, "self"))
+    let mut edits = refs
+        .references()
+        .iter()
+        .map(|(&file_id, references)| {
+            source_edit_from_references(sema, file_id, references, "self")
+        })
         .collect::<Vec<_>>();
 
     edits.push(SourceFileEdit {
@@ -467,7 +466,9 @@ fn rename_reference(
 
     let edit = refs
         .into_iter()
-        .map(|reference| source_edit_from_reference(sema, reference, new_name))
+        .map(|(file_id, references)| {
+            source_edit_from_references(sema, file_id, &references, new_name)
+        })
         .collect::<Vec<_>>();
 
     Ok(RangeInfo::new(range, SourceChange::from(edit)))
diff --git a/crates/ide/src/syntax_highlighting/highlights.rs b/crates/ide/src/syntax_highlighting/highlights.rs
index c6f0417ec..882a685a5 100644
--- a/crates/ide/src/syntax_highlighting/highlights.rs
+++ b/crates/ide/src/syntax_highlighting/highlights.rs
@@ -1,5 +1,5 @@
 //! Collects a tree of highlighted ranges and flattens it.
-use std::{cmp::Ordering, iter};
+use std::iter;
 
 use stdx::equal_range_by;
 use syntax::TextRange;
@@ -52,7 +52,7 @@ impl Node {
         }
 
         let overlapping =
-            equal_range_by(&self.nested, |n| ordering(n.hl_range.range, hl_range.range));
+            equal_range_by(&self.nested, |n| TextRange::ordering(n.hl_range.range, hl_range.range));
 
         if overlapping.len() == 1
             && self.nested[overlapping.start].hl_range.range.contains_range(hl_range.range)
@@ -90,13 +90,3 @@ impl Node {
         }
     }
 }
-
-pub(super) fn ordering(r1: TextRange, r2: TextRange) -> Ordering {
-    if r1.end() <= r2.start() {
-        Ordering::Less
-    } else if r2.end() <= r1.start() {
-        Ordering::Greater
-    } else {
-        Ordering::Equal
-    }
-}
diff --git a/crates/ide/src/syntax_highlighting/injector.rs b/crates/ide/src/syntax_highlighting/injector.rs
index fd4025694..24ff473ec 100644
--- a/crates/ide/src/syntax_highlighting/injector.rs
+++ b/crates/ide/src/syntax_highlighting/injector.rs
@@ -5,8 +5,6 @@ use std::ops::{self, Sub};
 use stdx::equal_range_by;
 use syntax::{TextRange, TextSize};
 
-use super::highlights::ordering;
-
 #[derive(Default)]
 pub(super) struct Injector {
     buf: String,
@@ -33,7 +31,7 @@ impl Injector {
         &self.buf
     }
     pub(super) fn map_range_up(&self, range: TextRange) -> impl Iterator<Item = TextRange> + '_ {
-        equal_range_by(&self.ranges, |&(r, _)| ordering(r, range)).filter_map(move |i| {
+        equal_range_by(&self.ranges, |&(r, _)| TextRange::ordering(r, range)).filter_map(move |i| {
             let (target_range, delta) = self.ranges[i];
             let intersection = target_range.intersect(range).unwrap();
             Some(intersection + delta?)
diff --git a/crates/ide_db/src/search.rs b/crates/ide_db/src/search.rs
index 773bfbc2c..b5fa46642 100644
--- a/crates/ide_db/src/search.rs
+++ b/crates/ide_db/src/search.rs
@@ -18,9 +18,43 @@ use crate::{
     RootDatabase,
 };
 
+#[derive(Debug, Default, Clone)]
+pub struct UsageSearchResult {
+    pub references: FxHashMap<FileId, Vec<FileReference>>,
+}
+
+impl UsageSearchResult {
+    pub fn is_empty(&self) -> bool {
+        self.references.is_empty()
+    }
+
+    pub fn len(&self) -> usize {
+        self.references.len()
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = (&FileId, &Vec<FileReference>)> + '_ {
+        self.references.iter()
+    }
+
+    pub fn file_ranges(&self) -> impl Iterator<Item = FileRange> + '_ {
+        self.references.iter().flat_map(|(&file_id, refs)| {
+            refs.iter().map(move |&FileReference { range, .. }| FileRange { file_id, range })
+        })
+    }
+}
+
+impl IntoIterator for UsageSearchResult {
+    type Item = (FileId, Vec<FileReference>);
+    type IntoIter = <FxHashMap<FileId, Vec<FileReference>> as IntoIterator>::IntoIter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.references.into_iter()
+    }
+}
+
 #[derive(Debug, Clone)]
-pub struct Reference {
-    pub file_range: FileRange,
+pub struct FileReference {
+    pub range: TextRange,
     pub kind: ReferenceKind,
     pub access: Option<ReferenceAccess>,
 }
@@ -252,23 +286,23 @@ impl<'a> FindUsages<'a> {
 
     pub fn at_least_one(self) -> bool {
         let mut found = false;
-        self.search(&mut |_reference| {
+        self.search(&mut |_, _| {
             found = true;
             true
         });
         found
     }
 
-    pub fn all(self) -> Vec<Reference> {
-        let mut res = Vec::new();
-        self.search(&mut |reference| {
-            res.push(reference);
+    pub fn all(self) -> UsageSearchResult {
+        let mut res = UsageSearchResult::default();
+        self.search(&mut |file_id, reference| {
+            res.references.entry(file_id).or_default().push(reference);
             false
         });
         res
     }
 
-    fn search(self, sink: &mut dyn FnMut(Reference) -> bool) {
+    fn search(self, sink: &mut dyn FnMut(FileId, FileReference) -> bool) {
         let _p = profile::span("FindUsages:search");
         let sema = self.sema;
 
@@ -320,16 +354,14 @@ impl<'a> FindUsages<'a> {
     fn found_lifetime(
         &self,
         lifetime: &ast::Lifetime,
-        sink: &mut dyn FnMut(Reference) -> bool,
+        sink: &mut dyn FnMut(FileId, FileReference) -> bool,
     ) -> bool {
         match NameRefClass::classify_lifetime(self.sema, lifetime) {
             Some(NameRefClass::Definition(def)) if &def == self.def => {
-                let reference = Reference {
-                    file_range: self.sema.original_range(lifetime.syntax()),
-                    kind: ReferenceKind::Lifetime,
-                    access: None,
-                };
-                sink(reference)
+                let FileRange { file_id, range } = self.sema.original_range(lifetime.syntax());
+                let reference =
+                    FileReference { range, kind: ReferenceKind::Lifetime, access: None };
+                sink(file_id, reference)
             }
             _ => false, // not a usage
         }
@@ -338,7 +370,7 @@ impl<'a> FindUsages<'a> {
     fn found_name_ref(
         &self,
         name_ref: &ast::NameRef,
-        sink: &mut dyn FnMut(Reference) -> bool,
+        sink: &mut dyn FnMut(FileId, FileReference) -> bool,
     ) -> bool {
         match NameRefClass::classify(self.sema, &name_ref) {
             Some(NameRefClass::Definition(def)) if &def == self.def => {
@@ -352,46 +384,50 @@ impl<'a> FindUsages<'a> {
                     ReferenceKind::Other
                 };
 
-                let reference = Reference {
-                    file_range: self.sema.original_range(name_ref.syntax()),
-                    kind,
-                    access: reference_access(&def, &name_ref),
-                };
-                sink(reference)
+                let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
+                let reference =
+                    FileReference { range, kind, access: reference_access(&def, &name_ref) };
+                sink(file_id, reference)
             }
             Some(NameRefClass::FieldShorthand { local_ref: local, field_ref: field }) => {
+                let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
                 let reference = match self.def {
-                    Definition::Field(_) if &field == self.def => Reference {
-                        file_range: self.sema.original_range(name_ref.syntax()),
+                    Definition::Field(_) if &field == self.def => FileReference {
+                        range,
                         kind: ReferenceKind::FieldShorthandForField,
                         access: reference_access(&field, &name_ref),
                     },
-                    Definition::Local(l) if &local == l => Reference {
-                        file_range: self.sema.original_range(name_ref.syntax()),
+                    Definition::Local(l) if &local == l => FileReference {
+                        range,
                         kind: ReferenceKind::FieldShorthandForLocal,
                         access: reference_access(&Definition::Local(local), &name_ref),
                     },
                     _ => return false, // not a usage
                 };
-                sink(reference)
+                sink(file_id, reference)
             }
             _ => false, // not a usage
         }
     }
 
-    fn found_name(&self, name: &ast::Name, sink: &mut dyn FnMut(Reference) -> bool) -> bool {
+    fn found_name(
+        &self,
+        name: &ast::Name,
+        sink: &mut dyn FnMut(FileId, FileReference) -> bool,
+    ) -> bool {
         match NameClass::classify(self.sema, name) {
             Some(NameClass::PatFieldShorthand { local_def: _, field_ref }) => {
-                let reference = match self.def {
-                    Definition::Field(_) if &field_ref == self.def => Reference {
-                        file_range: self.sema.original_range(name.syntax()),
-                        kind: ReferenceKind::FieldShorthandForField,
-                        // FIXME: mutable patterns should have `Write` access
-                        access: Some(ReferenceAccess::Read),
-                    },
-                    _ => return false, // not a usage
+                if !matches!(self.def, Definition::Field(_) if &field_ref == self.def) {
+                    return false;
+                }
+                let FileRange { file_id, range } = self.sema.original_range(name.syntax());
+                let reference = FileReference {
+                    range,
+                    kind: ReferenceKind::FieldShorthandForField,
+                    // FIXME: mutable patterns should have `Write` access
+                    access: Some(ReferenceAccess::Read),
                 };
-                sink(reference)
+                sink(file_id, reference)
             }
             _ => false, // not a usage
         }
diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index 3db0d55c5..f148521a2 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -75,14 +75,24 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
                 will_create: None,
                 did_rename: None,
                 will_rename: Some(FileOperationRegistrationOptions {
-                    filters: vec![FileOperationFilter {
-                        scheme: Some(String::from("file")),
-                        pattern: FileOperationPattern {
-                            glob: String::from("**/*.rs"),
-                            matches: Some(FileOperationPatternKind::File),
-                            options: None,
+                    filters: vec![
+                        FileOperationFilter {
+                            scheme: Some(String::from("file")),
+                            pattern: FileOperationPattern {
+                                glob: String::from("**/*.rs"),
+                                matches: Some(FileOperationPatternKind::File),
+                                options: None,
+                            },
                         },
-                    }],
+                        FileOperationFilter {
+                            scheme: Some(String::from("file")),
+                            pattern: FileOperationPattern {
+                                glob: String::from("**"),
+                                matches: Some(FileOperationPatternKind::Folder),
+                                options: None,
+                            },
+                        },
+                    ],
                 }),
                 did_delete: None,
                 will_delete: None,
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 29cc9051e..dc81f55d6 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -432,9 +432,27 @@ pub(crate) fn handle_will_rename_files(
             // Limit to single-level moves for now.
             match (from_path.parent(), to_path.parent()) {
                 (Some(p1), Some(p2)) if p1 == p2 => {
-                    let new_name = to_path.file_stem()?;
-                    let new_name = new_name.to_str()?;
-                    Some((snap.url_to_file_id(&from).ok()?, new_name.to_string()))
+                    if from_path.is_dir() {
+                        // add '/' to end of url -- from `file://path/to/folder` to `file://path/to/folder/`
+                        let mut old_folder_name = from_path.file_stem()?.to_str()?.to_string();
+                        old_folder_name.push('/');
+                        let from_with_trailing_slash = from.join(&old_folder_name).ok()?;
+
+                        let imitate_from_url = from_with_trailing_slash.join("mod.rs").ok()?;
+                        let new_file_name = to_path.file_name()?.to_str()?;
+                        Some((
+                            snap.url_to_file_id(&imitate_from_url).ok()?,
+                            new_file_name.to_string(),
+                        ))
+                    } else {
+                        let old_name = from_path.file_stem()?.to_str()?;
+                        let new_name = to_path.file_stem()?.to_str()?;
+                        match (old_name, new_name) {
+                            ("mod", _) => None,
+                            (_, "mod") => None,
+                            _ => Some((snap.url_to_file_id(&from).ok()?, new_name.to_string())),
+                        }
+                    }
                 }
                 _ => None,
             }
@@ -773,7 +791,8 @@ pub(crate) fn handle_prepare_rename(
     let _p = profile::span("handle_prepare_rename");
     let position = from_proto::file_position(&snap, params)?;
 
-    let change = snap.analysis.prepare_rename(position)??;
+    let change = snap.analysis.prepare_rename(position)?.map_err(to_proto::rename_error)?;
+
     let line_index = snap.analysis.file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, change.range);
     Ok(Some(PrepareRenameResponse::Range(range)))
@@ -786,15 +805,8 @@ pub(crate) fn handle_rename(
     let _p = profile::span("handle_rename");
     let position = from_proto::file_position(&snap, params.text_document_position)?;
 
-    if params.new_name.is_empty() {
-        return Err(LspError::new(
-            ErrorCode::InvalidParams as i32,
-            "New Name cannot be empty".into(),
-        )
-        .into());
-    }
-
-    let change = snap.analysis.rename(position, &*params.new_name)??;
+    let change =
+        snap.analysis.rename(position, &*params.new_name)?.map_err(to_proto::rename_error)?;
     let workspace_edit = to_proto::workspace_edit(&snap, change.info)?;
     Ok(Some(workspace_edit))
 }
@@ -812,14 +824,15 @@ pub(crate) fn handle_references(
     };
 
     let locations = if params.context.include_declaration {
-        refs.into_iter()
-            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
+        refs.references_with_declaration()
+            .file_ranges()
+            .filter_map(|frange| to_proto::location(&snap, frange).ok())
             .collect()
     } else {
         // Only iterate over the references if include_declaration was false
         refs.references()
-            .iter()
-            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
+            .file_ranges()
+            .filter_map(|frange| to_proto::location(&snap, frange).ok())
             .collect()
     };
 
@@ -1175,8 +1188,8 @@ pub(crate) fn handle_code_lens_resolve(
                 .unwrap_or(None)
                 .map(|r| {
                     r.references()
-                        .iter()
-                        .filter_map(|it| to_proto::location(&snap, it.file_range).ok())
+                        .file_ranges()
+                        .filter_map(|frange| to_proto::location(&snap, frange).ok())
                         .collect_vec()
                 })
                 .unwrap_or_default();
@@ -1220,13 +1233,19 @@ pub(crate) fn handle_document_highlight(
     };
 
     let res = refs
-        .into_iter()
-        .filter(|reference| reference.file_range.file_id == position.file_id)
-        .map(|reference| DocumentHighlight {
-            range: to_proto::range(&line_index, reference.file_range.range),
-            kind: reference.access.map(to_proto::document_highlight_kind),
+        .references_with_declaration()
+        .references
+        .get(&position.file_id)
+        .map(|file_refs| {
+            file_refs
+                .into_iter()
+                .map(|r| DocumentHighlight {
+                    range: to_proto::range(&line_index, r.range),
+                    kind: r.access.map(to_proto::document_highlight_kind),
+                })
+                .collect()
         })
-        .collect();
+        .unwrap_or_default();
     Ok(Some(res))
 }
 
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index bdddca9da..a7ff8975a 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -8,7 +8,8 @@ use ide::{
     Assist, AssistKind, CallInfo, CompletionItem, CompletionItemKind, Documentation, FileId,
     FileRange, FileSystemEdit, Fold, FoldKind, Highlight, HlMod, HlPunct, HlRange, HlTag, Indel,
     InlayHint, InlayKind, InsertTextFormat, LineIndex, Markup, NavigationTarget, ReferenceAccess,
-    Runnable, Severity, SourceChange, SourceFileEdit, SymbolKind, TextEdit, TextRange, TextSize,
+    RenameError, Runnable, Severity, SourceChange, SourceFileEdit, SymbolKind, TextEdit, TextRange,
+    TextSize,
 };
 use itertools::Itertools;
 
@@ -855,6 +856,10 @@ pub(crate) fn markup_content(markup: Markup) -> lsp_types::MarkupContent {
     lsp_types::MarkupContent { kind: lsp_types::MarkupKind::Markdown, value }
 }
 
+pub(crate) fn rename_error(err: RenameError) -> crate::LspError {
+    crate::LspError { code: lsp_server::ErrorCode::InvalidParams as i32, message: err.to_string() }
+}
+
 #[cfg(test)]
 mod tests {
     use ide::Analysis;
diff --git a/crates/rust-analyzer/tests/rust-analyzer/main.rs b/crates/rust-analyzer/tests/rust-analyzer/main.rs
index f5c5c63e5..80bde29b9 100644
--- a/crates/rust-analyzer/tests/rust-analyzer/main.rs
+++ b/crates/rust-analyzer/tests/rust-analyzer/main.rs
@@ -16,11 +16,14 @@ use std::{collections::HashMap, path::PathBuf, time::Instant};
 use expect_test::expect;
 use lsp_types::{
     notification::DidOpenTextDocument,
-    request::{CodeActionRequest, Completion, Formatting, GotoTypeDefinition, HoverRequest},
+    request::{
+        CodeActionRequest, Completion, Formatting, GotoTypeDefinition, HoverRequest,
+        WillRenameFiles,
+    },
     CodeActionContext, CodeActionParams, CompletionParams, DidOpenTextDocumentParams,
-    DocumentFormattingParams, FormattingOptions, GotoDefinitionParams, HoverParams,
-    PartialResultParams, Position, Range, TextDocumentItem, TextDocumentPositionParams,
-    WorkDoneProgressParams,
+    DocumentFormattingParams, FileRename, FormattingOptions, GotoDefinitionParams, HoverParams,
+    PartialResultParams, Position, Range, RenameFilesParams, TextDocumentItem,
+    TextDocumentPositionParams, WorkDoneProgressParams,
 };
 use rust_analyzer::lsp_ext::{OnEnter, Runnables, RunnablesParams};
 use serde_json::json;
@@ -745,3 +748,136 @@ pub fn foo(_input: TokenStream) -> TokenStream {
         ```"#]]
     .assert_eq(&value);
 }
+
+#[test]
+fn test_will_rename_files_same_level() {
+    if skip_slow_tests() {
+        return;
+    }
+
+    let tmp_dir = TestDir::new();
+    let tmp_dir_path = tmp_dir.path().to_owned();
+    let tmp_dir_str = tmp_dir_path.to_str().unwrap();
+    let base_path = PathBuf::from(format!("file://{}", tmp_dir_str));
+
+    let code = r#"
+//- /Cargo.toml
+[package]
+name = "foo"
+version = "0.0.0"
+
+//- /src/lib.rs
+mod old_file;
+mod from_mod;
+mod to_mod;
+mod old_folder;
+fn main() {}
+
+//- /src/old_file.rs
+
+//- /src/old_folder/mod.rs
+
+//- /src/from_mod/mod.rs
+
+//- /src/to_mod/foo.rs
+
+"#;
+    let server =
+        Project::with_fixture(&code).tmp_dir(tmp_dir).server().wait_until_workspace_is_loaded();
+
+    //rename same level file
+    server.request::<WillRenameFiles>(
+        RenameFilesParams {
+            files: vec![FileRename {
+                old_uri: base_path.join("src/old_file.rs").to_str().unwrap().to_string(),
+                new_uri: base_path.join("src/new_file.rs").to_str().unwrap().to_string(),
+            }],
+        },
+        json!({
+          "documentChanges": [
+            {
+              "textDocument": {
+                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").to_str().unwrap().to_string().replace("C:\\", "/c:/").replace("\\", "/")),
+                "version": null
+              },
+              "edits": [
+                {
+                  "range": {
+                    "start": {
+                      "line": 0,
+                      "character": 4
+                    },
+                    "end": {
+                      "line": 0,
+                      "character": 12
+                    }
+                  },
+                  "newText": "new_file"
+                }
+              ]
+            }
+          ]
+        }),
+    );
+
+    //rename file from mod.rs to foo.rs
+    server.request::<WillRenameFiles>(
+        RenameFilesParams {
+            files: vec![FileRename {
+                old_uri: base_path.join("src/from_mod/mod.rs").to_str().unwrap().to_string(),
+                new_uri: base_path.join("src/from_mod/foo.rs").to_str().unwrap().to_string(),
+            }],
+        },
+        json!({
+          "documentChanges": []
+        }),
+    );
+
+    //rename file from foo.rs to mod.rs
+    server.request::<WillRenameFiles>(
+        RenameFilesParams {
+            files: vec![FileRename {
+                old_uri: base_path.join("src/to_mod/foo.rs").to_str().unwrap().to_string(),
+                new_uri: base_path.join("src/to_mod/mod.rs").to_str().unwrap().to_string(),
+            }],
+        },
+        json!({
+          "documentChanges": []
+        }),
+    );
+
+    //rename same level file
+    server.request::<WillRenameFiles>(
+        RenameFilesParams {
+            files: vec![FileRename {
+                old_uri: base_path.join("src/old_folder").to_str().unwrap().to_string(),
+                new_uri: base_path.join("src/new_folder").to_str().unwrap().to_string(),
+            }],
+        },
+        json!({
+          "documentChanges": [
+            {
+              "textDocument": {
+                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").to_str().unwrap().to_string().replace("C:\\", "/c:/").replace("\\", "/")),
+                "version": null
+              },
+              "edits": [
+                {
+                  "range": {
+                    "start": {
+                      "line": 3,
+                      "character": 4
+                    },
+                    "end": {
+                      "line": 3,
+                      "character": 14
+                    }
+                  },
+                  "newText": "new_folder"
+                }
+              ]
+            }
+          ]
+        }),
+    );
+}
diff --git a/crates/ssr/src/search.rs b/crates/ssr/src/search.rs
index 44b5db029..836eb94b2 100644
--- a/crates/ssr/src/search.rs
+++ b/crates/ssr/src/search.rs
@@ -5,10 +5,10 @@ use crate::{
     resolving::{ResolvedPath, ResolvedPattern, ResolvedRule},
     Match, MatchFinder,
 };
-use ide_db::base_db::{FileId, FileRange};
 use ide_db::{
+    base_db::{FileId, FileRange},
     defs::Definition,
-    search::{Reference, SearchScope},
+    search::{SearchScope, UsageSearchResult},
 };
 use rustc_hash::FxHashSet;
 use syntax::{ast, AstNode, SyntaxKind, SyntaxNode};
@@ -20,7 +20,7 @@ use test_utils::mark;
 /// them more than once.
 #[derive(Default)]
 pub(crate) struct UsageCache {
-    usages: Vec<(Definition, Vec<Reference>)>,
+    usages: Vec<(Definition, UsageSearchResult)>,
 }
 
 impl<'db> MatchFinder<'db> {
@@ -58,8 +58,8 @@ impl<'db> MatchFinder<'db> {
     ) {
         if let Some(resolved_path) = pick_path_for_usages(pattern) {
             let definition: Definition = resolved_path.resolution.clone().into();
-            for reference in self.find_usages(usage_cache, definition) {
-                if let Some(node_to_match) = self.find_node_to_match(resolved_path, reference) {
+            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);
                         continue;
@@ -73,11 +73,11 @@ impl<'db> MatchFinder<'db> {
     fn find_node_to_match(
         &self,
         resolved_path: &ResolvedPath,
-        reference: &Reference,
+        file_range: FileRange,
     ) -> Option<SyntaxNode> {
-        let file = self.sema.parse(reference.file_range.file_id);
+        let file = self.sema.parse(file_range.file_id);
         let depth = resolved_path.depth as usize;
-        let offset = reference.file_range.range.start();
+        let offset = file_range.range.start();
         if let Some(path) =
             self.sema.find_node_at_offset_with_descend::<ast::Path>(file.syntax(), offset)
         {
@@ -108,7 +108,7 @@ impl<'db> MatchFinder<'db> {
         &self,
         usage_cache: &'a mut UsageCache,
         definition: Definition,
-    ) -> &'a [Reference] {
+    ) -> &'a UsageSearchResult {
         // Logically if a lookup succeeds we should just return it. Unfortunately returning it would
         // extend the lifetime of the borrow, then we wouldn't be able to do the insertion on a
         // cache miss. This is a limitation of NLL and is fixed with Polonius. For now we do two
@@ -250,7 +250,7 @@ fn is_search_permitted(node: &SyntaxNode) -> bool {
 }
 
 impl UsageCache {
-    fn find(&mut self, definition: &Definition) -> Option<&[Reference]> {
+    fn find(&mut self, definition: &Definition) -> Option<&UsageSearchResult> {
         // We expect a very small number of cache entries (generally 1), so a linear scan should be
         // fast enough and avoids the need to implement Hash for Definition.
         for (d, refs) in &self.usages {