2 files changed, 617 insertions, 119 deletions

diff --git a/crates/assists/src/assist_context.rs b/crates/assists/src/assist_context.rs
index 11c171fc2..bf520069e 100644
--- a/crates/assists/src/assist_context.rs
+++ b/crates/assists/src/assist_context.rs
@@ -73,10 +73,6 @@ impl<'a> AssistContext<'a> {
         self.sema.db
     }
 
-    pub(crate) fn source_file(&self) -> &SourceFile {
-        &self.source_file
-    }
-
     // NB, this ignores active selection.
     pub(crate) fn offset(&self) -> TextSize {
         self.frange.range.start()
diff --git a/crates/assists/src/handlers/expand_glob_import.rs b/crates/assists/src/handlers/expand_glob_import.rs
index 81d0af2f3..b39d040f6 100644
--- a/crates/assists/src/handlers/expand_glob_import.rs
+++ b/crates/assists/src/handlers/expand_glob_import.rs
@@ -1,10 +1,10 @@
 use either::Either;
-use hir::{AssocItem, MacroDef, ModuleDef, Name, PathResolution, ScopeDef, SemanticsScope};
+use hir::{AssocItem, MacroDef, Module, ModuleDef, Name, PathResolution, ScopeDef};
 use ide_db::{
     defs::{classify_name_ref, Definition, NameRefClass},
-    RootDatabase,
+    search::SearchScope,
 };
-use syntax::{algo, ast, match_ast, AstNode, SyntaxNode, SyntaxToken, T};
+use syntax::{algo, ast, AstNode, Direction, SyntaxNode, SyntaxToken, T};
 
 use crate::{
     assist_context::{AssistBuilder, AssistContext, Assists},
@@ -38,140 +38,259 @@ use crate::{
 // ```
 pub(crate) fn expand_glob_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let star = ctx.find_token_at_offset(T![*])?;
-    let mod_path = find_mod_path(&star)?;
-    let module = match ctx.sema.resolve_path(&mod_path)? {
+    let (parent, mod_path) = find_parent_and_path(&star)?;
+    let target_module = match ctx.sema.resolve_path(&mod_path)? {
         PathResolution::Def(ModuleDef::Module(it)) => it,
         _ => return None,
     };
 
-    let source_file = ctx.source_file();
-    let scope = ctx.sema.scope_at_offset(source_file.syntax(), ctx.offset());
+    let current_scope = ctx.sema.scope(&star.parent());
+    let current_module = current_scope.module()?;
 
-    let defs_in_mod = find_defs_in_mod(ctx, scope, module)?;
-    let name_refs_in_source_file =
-        source_file.syntax().descendants().filter_map(ast::NameRef::cast).collect();
-    let used_names = find_used_names(ctx, defs_in_mod, name_refs_in_source_file);
+    let refs_in_target = find_refs_in_mod(ctx, target_module, Some(current_module))?;
+    let imported_defs = find_imported_defs(ctx, star)?;
+    let names_to_import = find_names_to_import(ctx, refs_in_target, imported_defs);
 
-    let parent = star.parent().parent()?;
+    let target = parent.clone().either(|n| n.syntax().clone(), |n| n.syntax().clone());
     acc.add(
         AssistId("expand_glob_import", AssistKind::RefactorRewrite),
         "Expand glob import",
-        parent.text_range(),
+        target.text_range(),
         |builder| {
-            replace_ast(builder, &parent, mod_path, used_names);
+            replace_ast(builder, parent, mod_path, names_to_import);
         },
     )
 }
 
-fn find_mod_path(star: &SyntaxToken) -> Option<ast::Path> {
-    star.ancestors().find_map(|n| ast::UseTree::cast(n).and_then(|u| u.path()))
+fn find_parent_and_path(
+    star: &SyntaxToken,
+) -> Option<(Either<ast::UseTree, ast::UseTreeList>, ast::Path)> {
+    return star.ancestors().find_map(|n| {
+        find_use_tree_list(n.clone())
+            .and_then(|(u, p)| Some((Either::Right(u), p)))
+            .or_else(|| find_use_tree(n).and_then(|(u, p)| Some((Either::Left(u), p))))
+    });
+
+    fn find_use_tree_list(n: SyntaxNode) -> Option<(ast::UseTreeList, ast::Path)> {
+        let use_tree_list = ast::UseTreeList::cast(n)?;
+        let path = use_tree_list.parent_use_tree().path()?;
+        Some((use_tree_list, path))
+    }
+
+    fn find_use_tree(n: SyntaxNode) -> Option<(ast::UseTree, ast::Path)> {
+        let use_tree = ast::UseTree::cast(n)?;
+        let path = use_tree.path()?;
+        Some((use_tree, path))
+    }
 }
 
-#[derive(PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 enum Def {
     ModuleDef(ModuleDef),
     MacroDef(MacroDef),
 }
 
 impl Def {
-    fn name(&self, db: &RootDatabase) -> Option<Name> {
-        match self {
-            Def::ModuleDef(def) => def.name(db),
-            Def::MacroDef(def) => def.name(db),
+    fn is_referenced_in(&self, ctx: &AssistContext) -> bool {
+        let def = match self {
+            Def::ModuleDef(def) => Definition::ModuleDef(*def),
+            Def::MacroDef(def) => Definition::Macro(*def),
+        };
+
+        let search_scope = SearchScope::single_file(ctx.frange.file_id);
+        def.usages(&ctx.sema).in_scope(search_scope).at_least_one()
+    }
+}
+
+#[derive(Debug, Clone)]
+struct Ref {
+    // could be alias
+    visible_name: Name,
+    def: Def,
+}
+
+impl Ref {
+    fn from_scope_def(name: Name, scope_def: ScopeDef) -> Option<Self> {
+        match scope_def {
+            ScopeDef::ModuleDef(def) => Some(Ref { visible_name: name, def: Def::ModuleDef(def) }),
+            ScopeDef::MacroDef(def) => Some(Ref { visible_name: name, def: Def::MacroDef(def) }),
+            _ => None,
         }
     }
 }
 
-fn find_defs_in_mod(
+#[derive(Debug, Clone)]
+struct Refs(Vec<Ref>);
+
+impl Refs {
+    fn used_refs(&self, ctx: &AssistContext) -> Refs {
+        Refs(
+            self.0
+                .clone()
+                .into_iter()
+                .filter(|r| {
+                    if let Def::ModuleDef(ModuleDef::Trait(tr)) = r.def {
+                        if tr
+                            .items(ctx.db())
+                            .into_iter()
+                            .find(|ai| {
+                                if let AssocItem::Function(f) = *ai {
+                                    Def::ModuleDef(ModuleDef::Function(f)).is_referenced_in(ctx)
+                                } else {
+                                    false
+                                }
+                            })
+                            .is_some()
+                        {
+                            return true;
+                        }
+                    }
+
+                    r.def.is_referenced_in(ctx)
+                })
+                .collect(),
+        )
+    }
+
+    fn filter_out_by_defs(&self, defs: Vec<Def>) -> Refs {
+        Refs(self.0.clone().into_iter().filter(|r| !defs.contains(&r.def)).collect())
+    }
+}
+
+fn find_refs_in_mod(
     ctx: &AssistContext,
-    from: SemanticsScope<'_>,
-    module: hir::Module,
-) -> Option<Vec<Def>> {
-    let module_scope = module.scope(ctx.db(), from.module());
-
-    let mut defs = vec![];
-    for (_, def) in module_scope {
-        match def {
-            ScopeDef::ModuleDef(def) => defs.push(Def::ModuleDef(def)),
-            ScopeDef::MacroDef(def) => defs.push(Def::MacroDef(def)),
-            _ => continue,
+    module: Module,
+    visible_from: Option<Module>,
+) -> Option<Refs> {
+    if let Some(from) = visible_from {
+        if !is_mod_visible_from(ctx, module, from) {
+            return None;
         }
     }
 
-    Some(defs)
+    let module_scope = module.scope(ctx.db(), visible_from);
+    let refs = module_scope.into_iter().filter_map(|(n, d)| Ref::from_scope_def(n, d)).collect();
+    Some(Refs(refs))
 }
 
-fn find_used_names(
-    ctx: &AssistContext,
-    defs_in_mod: Vec<Def>,
-    name_refs_in_source_file: Vec<ast::NameRef>,
-) -> Vec<Name> {
-    let defs_in_source_file = name_refs_in_source_file
-        .iter()
-        .filter_map(|r| classify_name_ref(&ctx.sema, r))
-        .filter_map(|rc| match rc {
-            NameRefClass::Definition(Definition::ModuleDef(def)) => Some(Def::ModuleDef(def)),
-            NameRefClass::Definition(Definition::Macro(def)) => Some(Def::MacroDef(def)),
-            _ => None,
-        })
-        .collect::<Vec<Def>>();
+fn is_mod_visible_from(ctx: &AssistContext, module: Module, from: Module) -> bool {
+    match module.parent(ctx.db()) {
+        Some(parent) => {
+            parent.visibility_of(ctx.db(), &ModuleDef::Module(module)).map_or(true, |vis| {
+                vis.is_visible_from(ctx.db(), from.into()) && is_mod_visible_from(ctx, parent, from)
+            })
+        }
+        None => true,
+    }
+}
 
-    defs_in_mod
-        .iter()
-        .filter(|def| {
-            if let Def::ModuleDef(ModuleDef::Trait(tr)) = def {
-                for item in tr.items(ctx.db()) {
-                    if let AssocItem::Function(f) = item {
-                        if defs_in_source_file.contains(&Def::ModuleDef(ModuleDef::Function(f))) {
-                            return true;
-                        }
-                    }
-                }
-            }
+// looks for name refs in parent use block's siblings
+//
+// mod bar {
+//     mod qux {
+//         struct Qux;
+//     }
+//
+//     pub use qux::Qux;
+// }
+//
+// ↓ ---------------
+// use foo::*<|>;
+// use baz::Baz;
+// ↑ ---------------
+fn find_imported_defs(ctx: &AssistContext, star: SyntaxToken) -> Option<Vec<Def>> {
+    let parent_use_item_syntax =
+        star.ancestors().find_map(|n| if ast::Use::can_cast(n.kind()) { Some(n) } else { None })?;
+
+    Some(
+        [Direction::Prev, Direction::Next]
+            .iter()
+            .map(|dir| {
+                parent_use_item_syntax
+                    .siblings(dir.to_owned())
+                    .filter(|n| ast::Use::can_cast(n.kind()))
+            })
+            .flatten()
+            .filter_map(|n| Some(n.descendants().filter_map(ast::NameRef::cast)))
+            .flatten()
+            .filter_map(|r| match classify_name_ref(&ctx.sema, &r)? {
+                NameRefClass::Definition(Definition::ModuleDef(def)) => Some(Def::ModuleDef(def)),
+                NameRefClass::Definition(Definition::Macro(def)) => Some(Def::MacroDef(def)),
+                _ => None,
+            })
+            .collect(),
+    )
+}
 
-            defs_in_source_file.contains(def)
-        })
-        .filter_map(|d| d.name(ctx.db()))
-        .collect()
+fn find_names_to_import(
+    ctx: &AssistContext,
+    refs_in_target: Refs,
+    imported_defs: Vec<Def>,
+) -> Vec<Name> {
+    let used_refs = refs_in_target.used_refs(ctx).filter_out_by_defs(imported_defs);
+    used_refs.0.iter().map(|r| r.visible_name.clone()).collect()
 }
 
 fn replace_ast(
     builder: &mut AssistBuilder,
-    node: &SyntaxNode,
+    parent: Either<ast::UseTree, ast::UseTreeList>,
     path: ast::Path,
-    used_names: Vec<Name>,
+    names_to_import: Vec<Name>,
 ) {
-    let replacement: Either<ast::UseTree, ast::UseTreeList> = match used_names.as_slice() {
-        [name] => Either::Left(ast::make::use_tree(
-            ast::make::path_from_text(&format!("{}::{}", path, name)),
-            None,
-            None,
-            false,
-        )),
-        names => Either::Right(ast::make::use_tree_list(names.iter().map(|n| {
-            ast::make::use_tree(ast::make::path_from_text(&n.to_string()), None, None, false)
-        }))),
+    let existing_use_trees = match parent.clone() {
+        Either::Left(_) => vec![],
+        Either::Right(u) => u
+            .use_trees()
+            .filter(|n|
+            // filter out star
+            n.star_token().is_none())
+            .collect(),
     };
 
-    let mut replace_node = |replacement: Either<ast::UseTree, ast::UseTreeList>| {
-        algo::diff(node, &replacement.either(|u| u.syntax().clone(), |ut| ut.syntax().clone()))
+    let new_use_trees: Vec<ast::UseTree> = names_to_import
+        .iter()
+        .map(|n| ast::make::use_tree(ast::make::path_from_text(&n.to_string()), None, None, false))
+        .collect();
+
+    let use_trees = [&existing_use_trees[..], &new_use_trees[..]].concat();
+
+    match use_trees.as_slice() {
+        [name] => {
+            if let Some(end_path) = name.path() {
+                let replacement = ast::make::use_tree(
+                    ast::make::path_from_text(&format!("{}::{}", path, end_path)),
+                    None,
+                    None,
+                    false,
+                );
+
+                algo::diff(
+                    &parent.either(|n| n.syntax().clone(), |n| n.syntax().clone()),
+                    replacement.syntax(),
+                )
+                .into_text_edit(builder.text_edit_builder());
+            }
+        }
+        names => {
+            let replacement = match parent {
+                Either::Left(_) => ast::make::use_tree(
+                    path,
+                    Some(ast::make::use_tree_list(names.to_owned())),
+                    None,
+                    false,
+                )
+                .syntax()
+                .clone(),
+                Either::Right(_) => ast::make::use_tree_list(names.to_owned()).syntax().clone(),
+            };
+
+            algo::diff(
+                &parent.either(|n| n.syntax().clone(), |n| n.syntax().clone()),
+                &replacement,
+            )
             .into_text_edit(builder.text_edit_builder());
-    };
-
-    match_ast! {
-        match node {
-            ast::UseTree(use_tree) => {
-                replace_node(replacement);
-            },
-            ast::UseTreeList(use_tree_list) => {
-                replace_node(replacement);
-            },
-            ast::Use(use_item) => {
-                builder.replace_ast(use_item, ast::make::use_(replacement.left_or_else(|ut| ast::make::use_tree(path, Some(ut), None, false))));
-            },
-            _ => {},
         }
-    }
+    };
 }
 
 #[cfg(test)]
@@ -245,7 +364,46 @@ mod foo {
     pub fn f() {}
 }
 
-use foo::{Baz, Bar, f};
+use foo::{f, Baz, Bar};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+}
+",
+        )
+    }
+
+    #[test]
+    fn expanding_glob_import_with_existing_uses_in_same_module() {
+        check_assist(
+            expand_glob_import,
+            r"
+mod foo {
+    pub struct Bar;
+    pub struct Baz;
+    pub struct Qux;
+
+    pub fn f() {}
+}
+
+use foo::Bar;
+use foo::{*<|>, f};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+}
+",
+            r"
+mod foo {
+    pub struct Bar;
+    pub struct Baz;
+    pub struct Qux;
+
+    pub fn f() {}
+}
+
+use foo::Bar;
+use foo::{f, Baz};
 
 fn qux(bar: Bar, baz: Baz) {
     f();
@@ -260,7 +418,7 @@ fn qux(bar: Bar, baz: Baz) {
             expand_glob_import,
             r"
 mod foo {
-    mod bar {
+    pub mod bar {
         pub struct Bar;
         pub struct Baz;
         pub struct Qux;
@@ -268,7 +426,7 @@ mod foo {
         pub fn f() {}
     }
 
-    mod baz {
+    pub mod baz {
         pub fn g() {}
     }
 }
@@ -282,7 +440,7 @@ fn qux(bar: Bar, baz: Baz) {
 ",
             r"
 mod foo {
-    mod bar {
+    pub mod bar {
         pub struct Bar;
         pub struct Baz;
         pub struct Qux;
@@ -290,55 +448,359 @@ mod foo {
         pub fn f() {}
     }
 
-    mod baz {
+    pub mod baz {
         pub fn g() {}
     }
 }
 
-use foo::{bar::{Baz, Bar, f}, baz::*};
+use foo::{bar::{f, Baz, Bar}, baz::*};
 
 fn qux(bar: Bar, baz: Baz) {
     f();
     g();
 }
 ",
-        )
+        );
+
+        check_assist(
+            expand_glob_import,
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+    }
+}
+
+use foo::{bar::{Bar, Baz, f}, baz::*<|>};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+}
+",
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+    }
+}
+
+use foo::{bar::{Bar, Baz, f}, baz::g};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+}
+",
+        );
+
+        check_assist(
+            expand_glob_import,
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::*<|>}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    q::j();
+}
+",
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::{q, h}}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    q::j();
+}
+",
+        );
+
+        check_assist(
+            expand_glob_import,
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::{h, q::*<|>}}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    j();
+}
+",
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::{h, q::j}}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    j();
+}
+",
+        );
+
+        check_assist(
+            expand_glob_import,
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::{q::j, *<|>}}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    j();
+}
+",
+            r"
+mod foo {
+    pub mod bar {
+        pub struct Bar;
+        pub struct Baz;
+        pub struct Qux;
+
+        pub fn f() {}
+    }
+
+    pub mod baz {
+        pub fn g() {}
+
+        pub mod qux {
+            pub fn h() {}
+            pub fn m() {}
+
+            pub mod q {
+                pub fn j() {}
+            }
+        }
+    }
+}
+
+use foo::{
+    bar::{*, f},
+    baz::{g, qux::{q::j, h}}
+};
+
+fn qux(bar: Bar, baz: Baz) {
+    f();
+    g();
+    h();
+    j();
+}
+",
+        );
     }
 
     #[test]
     fn expanding_glob_import_with_macro_defs() {
+        // FIXME: this is currently fails because `Definition::find_usages` ignores macros
+        //       https://github.com/rust-analyzer/rust-analyzer/issues/3484
+        //
+        //         check_assist(
+        //             expand_glob_import,
+        //             r"
+        // //- /lib.rs crate:foo
+        // #[macro_export]
+        // macro_rules! bar {
+        //     () => ()
+        // }
+
+        // pub fn baz() {}
+
+        // //- /main.rs crate:main deps:foo
+        // use foo::*<|>;
+
+        // fn main() {
+        //     bar!();
+        //     baz();
+        // }
+        // ",
+        //             r"
+        // use foo::{bar, baz};
+
+        // fn main() {
+        //     bar!();
+        //     baz();
+        // }
+        // ",
+        //         )
+    }
+
+    #[test]
+    fn expanding_glob_import_with_trait_method_uses() {
         check_assist(
             expand_glob_import,
             r"
 //- /lib.rs crate:foo
-#[macro_export]
-macro_rules! bar {
-    () => ()
+pub trait Tr {
+    fn method(&self) {}
 }
-
-pub fn baz() {}
+impl Tr for () {}
 
 //- /main.rs crate:main deps:foo
 use foo::*<|>;
 
 fn main() {
-    bar!();
-    baz();
+    ().method();
 }
 ",
             r"
-use foo::{bar, baz};
+use foo::Tr;
 
 fn main() {
-    bar!();
-    baz();
+    ().method();
 }
 ",
-        )
-    }
+        );
 
-    #[test]
-    fn expanding_glob_import_with_trait_method_uses() {
         check_assist(
             expand_glob_import,
             r"
@@ -348,6 +810,11 @@ pub trait Tr {
 }
 impl Tr for () {}
 
+pub trait Tr2 {
+    fn method2(&self) {}
+}
+impl Tr2 for () {}
+
 //- /main.rs crate:main deps:foo
 use foo::*<|>;
 
@@ -362,7 +829,42 @@ fn main() {
     ().method();
 }
 ",
-        )
+        );
+    }
+
+    #[test]
+    fn expanding_is_not_applicable_if_target_module_is_not_accessible_from_current_scope() {
+        check_assist_not_applicable(
+            expand_glob_import,
+            r"
+mod foo {
+    mod bar {
+        pub struct Bar;
+    }
+}
+
+use foo::bar::*<|>;
+
+fn baz(bar: Bar) {}
+",
+        );
+
+        check_assist_not_applicable(
+            expand_glob_import,
+            r"
+mod foo {
+    mod bar {
+        pub mod baz {
+            pub struct Baz;
+        }
+    }
+}
+
+use foo::bar::baz::*<|>;
+
+fn qux(baz: Baz) {}
+",
+        );
     }
 
     #[test]