24 files changed, 703 insertions, 133 deletions

diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index 43f0d664b..2ab65ab99 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -101,7 +101,6 @@ impl<'a, DB: HirDatabase> AssistCtx<'a, DB> {
         Some(assist)
     }
 
-    #[allow(dead_code)] // will be used for auto import assist with multiple actions
     pub(crate) fn add_assist_group(
         self,
         id: AssistId,
@@ -168,7 +167,6 @@ pub(crate) struct ActionBuilder {
 }
 
 impl ActionBuilder {
-    #[allow(dead_code)]
     /// Adds a custom label to the action, if it needs to be different from the assist label
     pub(crate) fn label(&mut self, label: impl Into<String>) {
         self.label = Some(label.into())
diff --git a/crates/ra_assists/src/assists/auto_import.rs b/crates/ra_assists/src/assists/auto_import.rs
new file mode 100644
index 000000000..9163cc662
--- /dev/null
+++ b/crates/ra_assists/src/assists/auto_import.rs
@@ -0,0 +1,222 @@
+use hir::db::HirDatabase;
+use ra_syntax::{
+    ast::{self, AstNode},
+    SmolStr, SyntaxElement,
+    SyntaxKind::{NAME_REF, USE_ITEM},
+    SyntaxNode,
+};
+
+use crate::{
+    assist_ctx::{ActionBuilder, Assist, AssistCtx},
+    auto_import_text_edit, AssistId, ImportsLocator,
+};
+
+// Assist: auto_import
+//
+// If the name is unresolved, provides all possible imports for it.
+//
+// ```
+// fn main() {
+//     let map = HashMap<|>::new();
+// }
+// ```
+// ->
+// ```
+// use std::collections::HashMap;
+//
+// fn main() {
+//     let map = HashMap<|>::new();
+// }
+// ```
+pub(crate) fn auto_import<F: ImportsLocator>(
+    ctx: AssistCtx<impl HirDatabase>,
+    imports_locator: &mut F,
+) -> Option<Assist> {
+    let path: ast::Path = ctx.find_node_at_offset()?;
+    let module = path.syntax().ancestors().find_map(ast::Module::cast);
+    let position = match module.and_then(|it| it.item_list()) {
+        Some(item_list) => item_list.syntax().clone(),
+        None => {
+            let current_file = path.syntax().ancestors().find_map(ast::SourceFile::cast)?;
+            current_file.syntax().clone()
+        }
+    };
+    let source_analyzer = ctx.source_analyzer(&position, None);
+    let module_with_name_to_import = source_analyzer.module()?;
+    let path_to_import = ctx.covering_element().ancestors().find_map(ast::Path::cast)?;
+    if source_analyzer.resolve_path(ctx.db, &path_to_import).is_some() {
+        return None;
+    }
+
+    let name_to_import = &find_applicable_name_ref(ctx.covering_element())?.syntax().to_string();
+    let proposed_imports = imports_locator
+        .find_imports(&name_to_import.to_string())
+        .into_iter()
+        .filter_map(|module_def| module_with_name_to_import.find_use_path(ctx.db, module_def))
+        .filter(|use_path| !use_path.segments.is_empty())
+        .take(20)
+        .map(|import| import.to_string())
+        .collect::<std::collections::BTreeSet<_>>();
+    if proposed_imports.is_empty() {
+        return None;
+    }
+
+    ctx.add_assist_group(AssistId("auto_import"), "auto import", || {
+        proposed_imports
+            .into_iter()
+            .map(|import| import_to_action(import, &position, &path_to_import.syntax()))
+            .collect()
+    })
+}
+
+fn find_applicable_name_ref(element: SyntaxElement) -> Option<ast::NameRef> {
+    if element.ancestors().find(|ancestor| ancestor.kind() == USE_ITEM).is_some() {
+        None
+    } else if element.kind() == NAME_REF {
+        Some(element.as_node().cloned().and_then(ast::NameRef::cast)?)
+    } else {
+        let parent = element.parent()?;
+        if parent.kind() == NAME_REF {
+            Some(ast::NameRef::cast(parent)?)
+        } else {
+            None
+        }
+    }
+}
+
+fn import_to_action(import: String, position: &SyntaxNode, anchor: &SyntaxNode) -> ActionBuilder {
+    let mut action_builder = ActionBuilder::default();
+    action_builder.label(format!("Import `{}`", &import));
+    auto_import_text_edit(
+        position,
+        anchor,
+        &[SmolStr::new(import)],
+        action_builder.text_edit_builder(),
+    );
+    action_builder
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{
+        check_assist_with_imports_locator, check_assist_with_imports_locator_not_applicable,
+        TestImportsLocator,
+    };
+
+    #[test]
+    fn applicable_when_found_an_import() {
+        check_assist_with_imports_locator(
+            auto_import,
+            TestImportsLocator::new,
+            r"
+            PubStruct<|>
+
+            pub mod PubMod {
+                pub struct PubStruct;
+            }
+            ",
+            r"
+            use PubMod::PubStruct;
+
+            PubStruct<|>
+
+            pub mod PubMod {
+                pub struct PubStruct;
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn applicable_when_found_multiple_imports() {
+        check_assist_with_imports_locator(
+            auto_import,
+            TestImportsLocator::new,
+            r"
+            PubStruct<|>
+
+            pub mod PubMod1 {
+                pub struct PubStruct;
+            }
+            pub mod PubMod2 {
+                pub struct PubStruct;
+            }
+            pub mod PubMod3 {
+                pub struct PubStruct;
+            }
+            ",
+            r"
+            use PubMod1::PubStruct;
+
+            PubStruct<|>
+
+            pub mod PubMod1 {
+                pub struct PubStruct;
+            }
+            pub mod PubMod2 {
+                pub struct PubStruct;
+            }
+            pub mod PubMod3 {
+                pub struct PubStruct;
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_for_already_imported_types() {
+        check_assist_with_imports_locator_not_applicable(
+            auto_import,
+            TestImportsLocator::new,
+            r"
+            use PubMod::PubStruct;
+
+            PubStruct<|>
+
+            pub mod PubMod {
+                pub struct PubStruct;
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_for_types_with_private_paths() {
+        check_assist_with_imports_locator_not_applicable(
+            auto_import,
+            TestImportsLocator::new,
+            r"
+            PrivateStruct<|>
+
+            pub mod PubMod {
+                struct PrivateStruct;
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn not_applicable_when_no_imports_found() {
+        check_assist_with_imports_locator_not_applicable(
+            auto_import,
+            TestImportsLocator::new,
+            "
+            PubStruct<|>",
+        );
+    }
+
+    #[test]
+    fn not_applicable_in_import_statements() {
+        check_assist_with_imports_locator_not_applicable(
+            auto_import,
+            TestImportsLocator::new,
+            r"
+            use PubStruct<|>;
+
+            pub mod PubMod {
+                pub struct PubStruct;
+            }",
+        );
+    }
+}
diff --git a/crates/ra_assists/src/doc_tests.rs b/crates/ra_assists/src/doc_tests.rs
index 5dc1ee233..65d51428b 100644
--- a/crates/ra_assists/src/doc_tests.rs
+++ b/crates/ra_assists/src/doc_tests.rs
@@ -11,6 +11,10 @@ use test_utils::{assert_eq_text, extract_range_or_offset};
 use crate::test_db::TestDB;
 
 fn check(assist_id: &str, before: &str, after: &str) {
+    // FIXME we cannot get the imports search functionality here yet, but still need to generate a test and a doc for an assist
+    if assist_id == "auto_import" {
+        return;
+    }
     let (selection, before) = extract_range_or_offset(before);
     let (db, file_id) = TestDB::with_single_file(&before);
     let frange = FileRange { file_id, range: selection.into() };
diff --git a/crates/ra_assists/src/doc_tests/generated.rs b/crates/ra_assists/src/doc_tests/generated.rs
index 7d84dc8fb..ec4587ce7 100644
--- a/crates/ra_assists/src/doc_tests/generated.rs
+++ b/crates/ra_assists/src/doc_tests/generated.rs
@@ -215,6 +215,25 @@ fn main() {
 }
 
 #[test]
+fn doctest_auto_import() {
+    check(
+        "auto_import",
+        r#####"
+fn main() {
+    let map = HashMap<|>::new();
+}
+"#####,
+        r#####"
+use std::collections::HashMap;
+
+fn main() {
+    let map = HashMap<|>::new();
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_change_visibility() {
     check(
         "change_visibility",
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 3337805a5..625ebc4a2 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -14,7 +14,7 @@ mod test_db;
 pub mod ast_transform;
 
 use either::Either;
-use hir::db::HirDatabase;
+use hir::{db::HirDatabase, ModuleDef};
 use ra_db::FileRange;
 use ra_syntax::{TextRange, TextUnit};
 use ra_text_edit::TextEdit;
@@ -77,6 +77,51 @@ where
     })
 }
 
+/// A functionality for locating imports for the given name.
+///
+/// Currently has to be a trait with the real implementation provided by the ra_ide_api crate,
+/// due to the search functionality located there.
+/// Later, this trait should be removed completely and the search functionality moved to a separate crate,
+/// accessible from the ra_assists crate.
+pub trait ImportsLocator {
+    /// Finds all imports for the given name and the module that contains this name.
+    fn find_imports(&mut self, name_to_import: &str) -> Vec<ModuleDef>;
+}
+
+/// Return all the assists applicable at the given position
+/// and additional assists that need the imports locator functionality to work.
+///
+/// Assists are returned in the "resolved" state, that is with edit fully
+/// computed.
+pub fn assists_with_imports_locator<H, F>(
+    db: &H,
+    range: FileRange,
+    mut imports_locator: F,
+) -> Vec<ResolvedAssist>
+where
+    H: HirDatabase + 'static,
+    F: ImportsLocator,
+{
+    AssistCtx::with_ctx(db, range, true, |ctx| {
+        let mut assists = assists::all()
+            .iter()
+            .map(|f| f(ctx.clone()))
+            .chain(
+                assists::all_with_imports_locator()
+                    .iter()
+                    .map(|f| f(ctx.clone(), &mut imports_locator)),
+            )
+            .filter_map(std::convert::identity)
+            .map(|a| match a {
+                Assist::Resolved { assist } => assist,
+                Assist::Unresolved { .. } => unreachable!(),
+            })
+            .collect();
+        sort_assists(&mut assists);
+        assists
+    })
+}
+
 /// Return all the assists applicable at the given position.
 ///
 /// Assists are returned in the "resolved" state, that is with edit fully
@@ -85,8 +130,6 @@ pub fn assists<H>(db: &H, range: FileRange) -> Vec<ResolvedAssist>
 where
     H: HirDatabase + 'static,
 {
-    use std::cmp::Ordering;
-
     AssistCtx::with_ctx(db, range, true, |ctx| {
         let mut a = assists::all()
             .iter()
@@ -95,19 +138,24 @@ where
                 Assist::Resolved { assist } => assist,
                 Assist::Unresolved { .. } => unreachable!(),
             })
-            .collect::<Vec<_>>();
-        a.sort_by(|a, b| match (a.get_first_action().target, b.get_first_action().target) {
-            (Some(a), Some(b)) => a.len().cmp(&b.len()),
-            (Some(_), None) => Ordering::Less,
-            (None, Some(_)) => Ordering::Greater,
-            (None, None) => Ordering::Equal,
-        });
+            .collect();
+        sort_assists(&mut a);
         a
     })
 }
 
+fn sort_assists(assists: &mut Vec<ResolvedAssist>) {
+    use std::cmp::Ordering;
+    assists.sort_by(|a, b| match (a.get_first_action().target, b.get_first_action().target) {
+        (Some(a), Some(b)) => a.len().cmp(&b.len()),
+        (Some(_), None) => Ordering::Less,
+        (None, Some(_)) => Ordering::Greater,
+        (None, None) => Ordering::Equal,
+    });
+}
+
 mod assists {
-    use crate::{Assist, AssistCtx};
+    use crate::{Assist, AssistCtx, ImportsLocator};
     use hir::db::HirDatabase;
 
     mod add_derive;
@@ -116,6 +164,7 @@ mod assists {
     mod add_custom_impl;
     mod add_new;
     mod apply_demorgan;
+    mod auto_import;
     mod invert_if;
     mod flip_comma;
     mod flip_binexpr;
@@ -168,15 +217,69 @@ mod assists {
             early_return::convert_to_guarded_return,
         ]
     }
+
+    pub(crate) fn all_with_imports_locator<'a, DB: HirDatabase, F: ImportsLocator>(
+    ) -> &'a [fn(AssistCtx<DB>, &mut F) -> Option<Assist>] {
+        &[auto_import::auto_import]
+    }
 }
 
 #[cfg(test)]
 mod helpers {
-    use ra_db::{fixture::WithFixture, FileRange};
+    use hir::db::DefDatabase;
+    use ra_db::{fixture::WithFixture, FileId, FileRange};
     use ra_syntax::TextRange;
     use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
 
-    use crate::{test_db::TestDB, Assist, AssistCtx};
+    use crate::{test_db::TestDB, Assist, AssistCtx, ImportsLocator};
+    use std::sync::Arc;
+
+    // FIXME remove the `ModuleDefId` reexport from `ra_hir` when this gets removed.
+    pub(crate) struct TestImportsLocator {
+        db: Arc<TestDB>,
+        test_file_id: FileId,
+    }
+
+    impl TestImportsLocator {
+        pub(crate) fn new(db: Arc<TestDB>, test_file_id: FileId) -> Self {
+            TestImportsLocator { db, test_file_id }
+        }
+    }
+
+    impl ImportsLocator for TestImportsLocator {
+        fn find_imports(&mut self, name_to_import: &str) -> Vec<hir::ModuleDef> {
+            let crate_def_map = self.db.crate_def_map(self.db.test_crate());
+            let mut findings = Vec::new();
+
+            let mut module_ids_to_process =
+                crate_def_map.modules_for_file(self.test_file_id).collect::<Vec<_>>();
+
+            while !module_ids_to_process.is_empty() {
+                let mut more_ids_to_process = Vec::new();
+                for local_module_id in module_ids_to_process.drain(..) {
+                    for (name, namespace_data) in
+                        crate_def_map[local_module_id].scope.entries_without_primitives()
+                    {
+                        let found_a_match = &name.to_string() == name_to_import;
+                        vec![namespace_data.types, namespace_data.values]
+                            .into_iter()
+                            .filter_map(std::convert::identity)
+                            .for_each(|(module_def_id, _)| {
+                                if found_a_match {
+                                    findings.push(module_def_id.into());
+                                }
+                                if let hir::ModuleDefId::ModuleId(module_id) = module_def_id {
+                                    more_ids_to_process.push(module_id.local_id);
+                                }
+                            });
+                    }
+                }
+                module_ids_to_process = more_ids_to_process;
+            }
+
+            findings
+        }
+    }
 
     pub(crate) fn check_assist(
         assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
@@ -206,6 +309,38 @@ mod helpers {
         assert_eq_text!(after, &actual);
     }
 
+    pub(crate) fn check_assist_with_imports_locator<F: ImportsLocator>(
+        assist: fn(AssistCtx<TestDB>, &mut F) -> Option<Assist>,
+        imports_locator_provider: fn(db: Arc<TestDB>, file_id: FileId) -> F,
+        before: &str,
+        after: &str,
+    ) {
+        let (before_cursor_pos, before) = extract_offset(before);
+        let (db, file_id) = TestDB::with_single_file(&before);
+        let db = Arc::new(db);
+        let mut imports_locator = imports_locator_provider(Arc::clone(&db), file_id);
+        let frange =
+            FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
+        let assist =
+            AssistCtx::with_ctx(db.as_ref(), frange, true, |ctx| assist(ctx, &mut imports_locator))
+                .expect("code action is not applicable");
+        let action = match assist {
+            Assist::Unresolved { .. } => unreachable!(),
+            Assist::Resolved { assist } => assist.get_first_action(),
+        };
+
+        let actual = action.edit.apply(&before);
+        let actual_cursor_pos = match action.cursor_position {
+            None => action
+                .edit
+                .apply_to_offset(before_cursor_pos)
+                .expect("cursor position is affected by the edit"),
+            Some(off) => off,
+        };
+        let actual = add_cursor(&actual, actual_cursor_pos);
+        assert_eq_text!(after, &actual);
+    }
+
     pub(crate) fn check_assist_range(
         assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
@@ -279,6 +414,22 @@ mod helpers {
         assert!(assist.is_none());
     }
 
+    pub(crate) fn check_assist_with_imports_locator_not_applicable<F: ImportsLocator>(
+        assist: fn(AssistCtx<TestDB>, &mut F) -> Option<Assist>,
+        imports_locator_provider: fn(db: Arc<TestDB>, file_id: FileId) -> F,
+        before: &str,
+    ) {
+        let (before_cursor_pos, before) = extract_offset(before);
+        let (db, file_id) = TestDB::with_single_file(&before);
+        let db = Arc::new(db);
+        let mut imports_locator = imports_locator_provider(Arc::clone(&db), file_id);
+        let frange =
+            FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
+        let assist =
+            AssistCtx::with_ctx(db.as_ref(), frange, true, |ctx| assist(ctx, &mut imports_locator));
+        assert!(assist.is_none());
+    }
+
     pub(crate) fn check_assist_range_not_applicable(
         assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
diff --git a/crates/ra_cargo_watch/Cargo.toml b/crates/ra_cargo_watch/Cargo.toml
index e88295539..49e06e0d3 100644
--- a/crates/ra_cargo_watch/Cargo.toml
+++ b/crates/ra_cargo_watch/Cargo.toml
@@ -13,5 +13,5 @@ jod-thread = "0.1.0"
 parking_lot = "0.10.0"
 
 [dev-dependencies]
-insta = "0.12.0"
+insta = "0.13.0"
 serde_json = "1.0"
\ No newline at end of file
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_clippy_pass_by_ref.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap
index cb0920914..cb0920914 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_clippy_pass_by_ref.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_clippy_pass_by_ref.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_handles_macro_location.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap
index 19510ecc1..19510ecc1 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_handles_macro_location.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_handles_macro_location.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_macro_compiler_error.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap
index 92f7eec05..92f7eec05 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_macro_compiler_error.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_macro_compiler_error.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_incompatible_type_for_trait.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap
index cf683e4b6..cf683e4b6 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_incompatible_type_for_trait.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_incompatible_type_for_trait.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_mismatched_type.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap
index 8c1483c74..8c1483c74 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_mismatched_type.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_mismatched_type.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_unused_variable.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap
index eb5a2247b..eb5a2247b 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_unused_variable.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_unused_variable.snap
diff --git a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_wrong_number_of_parameters.snap b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap
index 2f4518931..2f4518931 100644
--- a/crates/ra_cargo_watch/src/conv/snapshots/test__snap_rustc_wrong_number_of_parameters.snap
+++ b/crates/ra_cargo_watch/src/conv/snapshots/ra_cargo_watch__conv__test__snap_rustc_wrong_number_of_parameters.snap
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index e1c7b7a20..9e2673d13 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -56,6 +56,7 @@ pub use hir_def::{
     nameres::ModuleSource,
     path::{ModPath, Path, PathKind},
     type_ref::Mutability,
+    ModuleDefId, // FIXME this is exposed and should be used for implementing the `TestImportsLocator` in `ra_assists` only, should be removed later along with the trait and the implementation.
 };
 pub use hir_expand::{
     name::Name, HirFileId, InFile, MacroCallId, MacroCallLoc, MacroDefId, MacroFile, Origin,
diff --git a/crates/ra_hir_def/Cargo.toml b/crates/ra_hir_def/Cargo.toml
index 2c368f690..1efa00fe0 100644
--- a/crates/ra_hir_def/Cargo.toml
+++ b/crates/ra_hir_def/Cargo.toml
@@ -26,4 +26,4 @@ ra_cfg = { path = "../ra_cfg" }
 tt = { path = "../ra_tt", package = "ra_tt" }
 
 [dev-dependencies]
-insta = "0.12.0"
+insta = "0.13.0"
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 60793db44..d229639d9 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -28,4 +28,4 @@ chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5a
 lalrpop-intern = "0.15.1"
 
 [dev-dependencies]
-insta = "0.12.0"
+insta = "0.13.0"
diff --git a/crates/ra_ide/Cargo.toml b/crates/ra_ide/Cargo.toml
index 2c9f9dce0..53817d1f7 100644
--- a/crates/ra_ide/Cargo.toml
+++ b/crates/ra_ide/Cargo.toml
@@ -39,7 +39,7 @@ ra_assists = { path = "../ra_assists" }
 hir = { path = "../ra_hir", package = "ra_hir" }
 
 [dev-dependencies]
-insta = "0.12.0"
+insta = "0.13.0"
 
 [dev-dependencies.proptest]
 version = "0.9.0"
diff --git a/crates/ra_ide/src/assists.rs b/crates/ra_ide/src/assists.rs
index a936900da..c43c45c65 100644
--- a/crates/ra_ide/src/assists.rs
+++ b/crates/ra_ide/src/assists.rs
@@ -2,8 +2,9 @@
 
 use ra_db::{FilePosition, FileRange};
 
-use crate::{db::RootDatabase, FileId, SourceChange, SourceFileEdit};
-
+use crate::{
+    db::RootDatabase, imports_locator::ImportsLocatorIde, FileId, SourceChange, SourceFileEdit,
+};
 use either::Either;
 pub use ra_assists::AssistId;
 use ra_assists::{AssistAction, AssistLabel};
@@ -16,7 +17,7 @@ pub struct Assist {
 }
 
 pub(crate) fn assists(db: &RootDatabase, frange: FileRange) -> Vec<Assist> {
-    ra_assists::assists(db, frange)
+    ra_assists::assists_with_imports_locator(db, frange, ImportsLocatorIde::new(db))
         .into_iter()
         .map(|assist| {
             let file_id = frange.file_id;
diff --git a/crates/ra_ide/src/expand.rs b/crates/ra_ide/src/expand.rs
index b82259a3d..831438c09 100644
--- a/crates/ra_ide/src/expand.rs
+++ b/crates/ra_ide/src/expand.rs
@@ -79,6 +79,14 @@ pub(crate) fn descend_into_macros(
     let source_analyzer =
         hir::SourceAnalyzer::new(db, src.with_value(src.value.parent()).as_ref(), None);
 
+    descend_into_macros_with_analyzer(db, &source_analyzer, src)
+}
+
+pub(crate) fn descend_into_macros_with_analyzer(
+    db: &RootDatabase,
+    source_analyzer: &hir::SourceAnalyzer,
+    src: InFile<SyntaxToken>,
+) -> InFile<SyntaxToken> {
     successors(Some(src), |token| {
         let macro_call = token.value.ancestors().find_map(ast::MacroCall::cast)?;
         let tt = macro_call.token_tree()?;
diff --git a/crates/ra_ide/src/imports_locator.rs b/crates/ra_ide/src/imports_locator.rs
new file mode 100644
index 000000000..48b014c7d
--- /dev/null
+++ b/crates/ra_ide/src/imports_locator.rs
@@ -0,0 +1,76 @@
+//! This module contains an import search funcionality that is provided to the ra_assists module.
+//! Later, this should be moved away to a separate crate that is accessible from the ra_assists module.
+
+use crate::{
+    db::RootDatabase,
+    references::{classify_name, NameDefinition, NameKind},
+    symbol_index::{self, FileSymbol},
+    Query,
+};
+use hir::{db::HirDatabase, ModuleDef, SourceBinder};
+use ra_assists::ImportsLocator;
+use ra_prof::profile;
+use ra_syntax::{ast, AstNode, SyntaxKind::NAME};
+
+pub(crate) struct ImportsLocatorIde<'a> {
+    source_binder: SourceBinder<'a, RootDatabase>,
+}
+
+impl<'a> ImportsLocatorIde<'a> {
+    pub(crate) fn new(db: &'a RootDatabase) -> Self {
+        Self { source_binder: SourceBinder::new(db) }
+    }
+
+    fn get_name_definition(
+        &mut self,
+        db: &impl HirDatabase,
+        import_candidate: &FileSymbol,
+    ) -> Option<NameDefinition> {
+        let _p = profile("get_name_definition");
+        let file_id = import_candidate.file_id.into();
+        let candidate_node = import_candidate.ptr.to_node(&db.parse_or_expand(file_id)?);
+        let candidate_name_node = if candidate_node.kind() != NAME {
+            candidate_node.children().find(|it| it.kind() == NAME)?
+        } else {
+            candidate_node
+        };
+        classify_name(
+            &mut self.source_binder,
+            hir::InFile { file_id, value: &ast::Name::cast(candidate_name_node)? },
+        )
+    }
+}
+
+impl ImportsLocator for ImportsLocatorIde<'_> {
+    fn find_imports(&mut self, name_to_import: &str) -> Vec<ModuleDef> {
+        let _p = profile("search_for_imports");
+        let db = self.source_binder.db;
+
+        let project_results = {
+            let mut query = Query::new(name_to_import.to_string());
+            query.exact();
+            query.limit(40);
+            symbol_index::world_symbols(db, query)
+        };
+        let lib_results = {
+            let mut query = Query::new(name_to_import.to_string());
+            query.libs();
+            query.exact();
+            query.limit(40);
+            symbol_index::world_symbols(db, query)
+        };
+
+        project_results
+            .into_iter()
+            .chain(lib_results.into_iter())
+            .filter_map(|import_candidate| self.get_name_definition(db, &import_candidate))
+            .filter_map(|name_definition_to_import| {
+                if let NameKind::Def(module_def) = name_definition_to_import.kind {
+                    Some(module_def)
+                } else {
+                    None
+                }
+            })
+            .collect()
+    }
+}
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 62fe6d2a9..03ad6b2c1 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -30,6 +30,7 @@ mod syntax_highlighting;
 mod parent_module;
 mod references;
 mod impls;
+mod imports_locator;
 mod assists;
 mod diagnostics;
 mod syntax_tree;
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 1d130544f..1cc55e78b 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -34,6 +34,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="function">foo</span>::&lt;<span class="type.builtin">i32</span>&gt;();
 }
 
+<span class="macro">macro_rules</span><span class="macro">!</span> def_fn {
+    ($($tt:tt)*) =&gt; {$($tt)*}
+}
+
+<span class="macro">def_fn</span><span class="macro">!</span>{
+    <span class="keyword">fn</span> <span class="function">bar</span>() -&gt; <span class="type.builtin">u32</span> {
+        <span class="literal.numeric">100</span>
+    }
+}
+
 <span class="comment">// comment</span>
 <span class="keyword">fn</span> <span class="function">main</span>() {
     <span class="macro">println</span><span class="macro">!</span>(<span class="string">"Hello, {}!"</span>, <span class="literal.numeric">92</span>);
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index d90ee8540..918fd4b97 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -24,14 +24,14 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .keyword\.control  { color: #F0DFAF; font-weight: bold; }
 </style>
 <pre><code><span class="keyword">fn</span> <span class="function">main</span>() {
-    <span class="keyword">let</span> <span class="variable" data-binding-hash="8723171760279909834" style="color: hsl(307,91%,75%);">hello</span> = <span class="string">"hello"</span>;
-    <span class="keyword">let</span> <span class="variable" data-binding-hash="14702933417323009544" style="color: hsl(108,90%,49%);">x</span> = <span class="variable" data-binding-hash="8723171760279909834" style="color: hsl(307,91%,75%);">hello</span>.to_string();
-    <span class="keyword">let</span> <span class="variable" data-binding-hash="5443150872754369068" style="color: hsl(215,43%,43%);">y</span> = <span class="variable" data-binding-hash="8723171760279909834" style="color: hsl(307,91%,75%);">hello</span>.to_string();
+    <span class="keyword">let</span> <span class="variable" data-binding-hash="2217585909179791122" style="color: hsl(280,74%,48%);">hello</span> = <span class="string">"hello"</span>;
+    <span class="keyword">let</span> <span class="variable" data-binding-hash="4303609361109701698" style="color: hsl(242,75%,88%);">x</span> = <span class="variable" data-binding-hash="2217585909179791122" style="color: hsl(280,74%,48%);">hello</span>.to_string();
+    <span class="keyword">let</span> <span class="variable" data-binding-hash="13865792086344377029" style="color: hsl(340,64%,86%);">y</span> = <span class="variable" data-binding-hash="2217585909179791122" style="color: hsl(280,74%,48%);">hello</span>.to_string();
 
-    <span class="keyword">let</span> <span class="variable" data-binding-hash="17358108296605513516" style="color: hsl(331,46%,60%);">x</span> = <span class="string">"other color please!"</span>;
-    <span class="keyword">let</span> <span class="variable" data-binding-hash="2073121142529774969" style="color: hsl(320,43%,74%);">y</span> = <span class="variable" data-binding-hash="17358108296605513516" style="color: hsl(331,46%,60%);">x</span>.to_string();
+    <span class="keyword">let</span> <span class="variable" data-binding-hash="7011301204224269512" style="color: hsl(198,45%,40%);">x</span> = <span class="string">"other color please!"</span>;
+    <span class="keyword">let</span> <span class="variable" data-binding-hash="12461245066629867975" style="color: hsl(132,91%,68%);">y</span> = <span class="variable" data-binding-hash="7011301204224269512" style="color: hsl(198,45%,40%);">x</span>.to_string();
 }
 
 <span class="keyword">fn</span> <span class="function">bar</span>() {
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable.mut" data-binding-hash="8723171760279909834" style="color: hsl(307,91%,75%);">hello</span> = <span class="string">"hello"</span>;
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable.mut" data-binding-hash="2217585909179791122" style="color: hsl(280,74%,48%);">hello</span> = <span class="string">"hello"</span>;
 }</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 0411977b9..530b984fc 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -1,14 +1,18 @@
 //! FIXME: write short doc here
 
-use rustc_hash::{FxHashMap, FxHashSet};
+use rustc_hash::FxHashMap;
 
-use hir::{InFile, Name, SourceBinder};
+use hir::{HirFileId, InFile, Name, SourceAnalyzer, SourceBinder};
 use ra_db::SourceDatabase;
 use ra_prof::profile;
-use ra_syntax::{ast, AstNode, Direction, SyntaxElement, SyntaxKind, SyntaxKind::*, TextRange, T};
+use ra_syntax::{
+    ast, AstNode, Direction, SyntaxElement, SyntaxKind, SyntaxKind::*, SyntaxToken, TextRange,
+    WalkEvent, T,
+};
 
 use crate::{
     db::RootDatabase,
+    expand::descend_into_macros_with_analyzer,
     references::{
         classify_name, classify_name_ref,
         NameKind::{self, *},
@@ -72,121 +76,186 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
     let parse = db.parse(file_id);
     let root = parse.tree().syntax().clone();
 
-    fn calc_binding_hash(file_id: FileId, name: &Name, shadow_count: u32) -> u64 {
-        fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
-            use std::{collections::hash_map::DefaultHasher, hash::Hasher};
+    let mut sb = SourceBinder::new(db);
+    let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
+    let mut res = Vec::new();
+    let analyzer = sb.analyze(InFile::new(file_id.into(), &root), None);
 
-            let mut hasher = DefaultHasher::new();
-            x.hash(&mut hasher);
-            hasher.finish()
+    let mut in_macro_call = None;
+
+    for event in root.preorder_with_tokens() {
+        match event {
+            WalkEvent::Enter(node) => match node.kind() {
+                MACRO_CALL => {
+                    in_macro_call = Some(node.clone());
+                    if let Some(range) = highlight_macro(InFile::new(file_id.into(), node)) {
+                        res.push(HighlightedRange { range, tag: tags::MACRO, binding_hash: None });
+                    }
+                }
+                _ if in_macro_call.is_some() => {
+                    if let Some(token) = node.as_token() {
+                        if let Some((tag, binding_hash)) = highlight_token_tree(
+                            db,
+                            &mut sb,
+                            &analyzer,
+                            &mut bindings_shadow_count,
+                            InFile::new(file_id.into(), token.clone()),
+                        ) {
+                            res.push(HighlightedRange {
+                                range: node.text_range(),
+                                tag,
+                                binding_hash,
+                            });
+                        }
+                    }
+                }
+                _ => {
+                    if let Some((tag, binding_hash)) = highlight_node(
+                        db,
+                        &mut sb,
+                        &mut bindings_shadow_count,
+                        InFile::new(file_id.into(), node.clone()),
+                    ) {
+                        res.push(HighlightedRange { range: node.text_range(), tag, binding_hash });
+                    }
+                }
+            },
+            WalkEvent::Leave(node) => {
+                if let Some(m) = in_macro_call.as_ref() {
+                    if *m == node {
+                        in_macro_call = None;
+                    }
+                }
+            }
         }
+    }
 
-        hash((file_id, name, shadow_count))
+    res
+}
+
+fn highlight_macro(node: InFile<SyntaxElement>) -> Option<TextRange> {
+    let macro_call = ast::MacroCall::cast(node.value.as_node()?.clone())?;
+    let path = macro_call.path()?;
+    let name_ref = path.segment()?.name_ref()?;
+
+    let range_start = name_ref.syntax().text_range().start();
+    let mut range_end = name_ref.syntax().text_range().end();
+    for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
+        match sibling.kind() {
+            T![!] | IDENT => range_end = sibling.text_range().end(),
+            _ => (),
+        }
     }
 
-    let mut sb = SourceBinder::new(db);
+    Some(TextRange::from_to(range_start, range_end))
+}
 
-    // Visited nodes to handle highlighting priorities
-    // FIXME: retain only ranges here
-    let mut highlighted: FxHashSet<SyntaxElement> = FxHashSet::default();
-    let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
+fn highlight_token_tree(
+    db: &RootDatabase,
+    sb: &mut SourceBinder<RootDatabase>,
+    analyzer: &SourceAnalyzer,
+    bindings_shadow_count: &mut FxHashMap<Name, u32>,
+    token: InFile<SyntaxToken>,
+) -> Option<(&'static str, Option<u64>)> {
+    if token.value.parent().kind() != TOKEN_TREE {
+        return None;
+    }
+    let token = descend_into_macros_with_analyzer(db, analyzer, token);
+    let expanded = {
+        let parent = token.value.parent();
+        // We only care Name and Name_ref
+        match (token.value.kind(), parent.kind()) {
+            (IDENT, NAME) | (IDENT, NAME_REF) => token.with_value(parent.into()),
+            _ => token.map(|it| it.into()),
+        }
+    };
 
-    let mut res = Vec::new();
-    for node in root.descendants_with_tokens() {
-        if highlighted.contains(&node) {
-            continue;
+    highlight_node(db, sb, bindings_shadow_count, expanded)
+}
+
+fn highlight_node(
+    db: &RootDatabase,
+    sb: &mut SourceBinder<RootDatabase>,
+    bindings_shadow_count: &mut FxHashMap<Name, u32>,
+    node: InFile<SyntaxElement>,
+) -> Option<(&'static str, Option<u64>)> {
+    let mut binding_hash = None;
+    let tag = match node.value.kind() {
+        FN_DEF => {
+            bindings_shadow_count.clear();
+            return None;
         }
-        let mut binding_hash = None;
-        let tag = match node.kind() {
-            FN_DEF => {
-                bindings_shadow_count.clear();
-                continue;
-            }
-            COMMENT => tags::LITERAL_COMMENT,
-            STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => tags::LITERAL_STRING,
-            ATTR => tags::LITERAL_ATTRIBUTE,
-            // Special-case field init shorthand
-            NAME_REF if node.parent().and_then(ast::RecordField::cast).is_some() => tags::FIELD,
-            NAME_REF if node.ancestors().any(|it| it.kind() == ATTR) => continue,
-            NAME_REF => {
-                let name_ref = node.as_node().cloned().and_then(ast::NameRef::cast).unwrap();
-                let name_kind = classify_name_ref(&mut sb, InFile::new(file_id.into(), &name_ref))
-                    .map(|d| d.kind);
-                match name_kind {
-                    Some(name_kind) => {
-                        if let Local(local) = &name_kind {
-                            if let Some(name) = local.name(db) {
-                                let shadow_count =
-                                    bindings_shadow_count.entry(name.clone()).or_default();
-                                binding_hash =
-                                    Some(calc_binding_hash(file_id, &name, *shadow_count))
-                            }
-                        };
-
-                        highlight_name(db, name_kind)
-                    }
-                    _ => continue,
-                }
-            }
-            NAME => {
-                let name = node.as_node().cloned().and_then(ast::Name::cast).unwrap();
-                let name_kind =
-                    classify_name(&mut sb, InFile::new(file_id.into(), &name)).map(|d| d.kind);
-
-                if let Some(Local(local)) = &name_kind {
-                    if let Some(name) = local.name(db) {
-                        let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
-                        *shadow_count += 1;
-                        binding_hash = Some(calc_binding_hash(file_id, &name, *shadow_count))
-                    }
-                };
-
-                match name_kind {
-                    Some(name_kind) => highlight_name(db, name_kind),
-                    None => name.syntax().parent().map_or(tags::FUNCTION, |x| match x.kind() {
-                        STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF => tags::TYPE,
-                        TYPE_PARAM => tags::TYPE_PARAM,
-                        RECORD_FIELD_DEF => tags::FIELD,
-                        _ => tags::FUNCTION,
-                    }),
+        COMMENT => tags::LITERAL_COMMENT,
+        STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => tags::LITERAL_STRING,
+        ATTR => tags::LITERAL_ATTRIBUTE,
+        // Special-case field init shorthand
+        NAME_REF if node.value.parent().and_then(ast::RecordField::cast).is_some() => tags::FIELD,
+        NAME_REF if node.value.ancestors().any(|it| it.kind() == ATTR) => return None,
+        NAME_REF => {
+            let name_ref = node.value.as_node().cloned().and_then(ast::NameRef::cast).unwrap();
+            let name_kind = classify_name_ref(sb, node.with_value(&name_ref)).map(|d| d.kind);
+            match name_kind {
+                Some(name_kind) => {
+                    if let Local(local) = &name_kind {
+                        if let Some(name) = local.name(db) {
+                            let shadow_count =
+                                bindings_shadow_count.entry(name.clone()).or_default();
+                            binding_hash =
+                                Some(calc_binding_hash(node.file_id, &name, *shadow_count))
+                        }
+                    };
+
+                    highlight_name(db, name_kind)
                 }
+                _ => return None,
             }
-            INT_NUMBER | FLOAT_NUMBER => tags::LITERAL_NUMERIC,
-            BYTE => tags::LITERAL_BYTE,
-            CHAR => tags::LITERAL_CHAR,
-            LIFETIME => tags::TYPE_LIFETIME,
-            T![unsafe] => tags::KEYWORD_UNSAFE,
-            k if is_control_keyword(k) => tags::KEYWORD_CONTROL,
-            k if k.is_keyword() => tags::KEYWORD,
-            _ => {
-                if let Some(macro_call) = node.as_node().cloned().and_then(ast::MacroCall::cast) {
-                    if let Some(path) = macro_call.path() {
-                        if let Some(segment) = path.segment() {
-                            if let Some(name_ref) = segment.name_ref() {
-                                highlighted.insert(name_ref.syntax().clone().into());
-                                let range_start = name_ref.syntax().text_range().start();
-                                let mut range_end = name_ref.syntax().text_range().end();
-                                for sibling in path.syntax().siblings_with_tokens(Direction::Next) {
-                                    match sibling.kind() {
-                                        T![!] | IDENT => range_end = sibling.text_range().end(),
-                                        _ => (),
-                                    }
-                                }
-                                res.push(HighlightedRange {
-                                    range: TextRange::from_to(range_start, range_end),
-                                    tag: tags::MACRO,
-                                    binding_hash: None,
-                                })
-                            }
-                        }
-                    }
+        }
+        NAME => {
+            let name = node.value.as_node().cloned().and_then(ast::Name::cast).unwrap();
+            let name_kind = classify_name(sb, node.with_value(&name)).map(|d| d.kind);
+
+            if let Some(Local(local)) = &name_kind {
+                if let Some(name) = local.name(db) {
+                    let shadow_count = bindings_shadow_count.entry(name.clone()).or_default();
+                    *shadow_count += 1;
+                    binding_hash = Some(calc_binding_hash(node.file_id, &name, *shadow_count))
                 }
-                continue;
+            };
+
+            match name_kind {
+                Some(name_kind) => highlight_name(db, name_kind),
+                None => name.syntax().parent().map_or(tags::FUNCTION, |x| match x.kind() {
+                    STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF => tags::TYPE,
+                    TYPE_PARAM => tags::TYPE_PARAM,
+                    RECORD_FIELD_DEF => tags::FIELD,
+                    _ => tags::FUNCTION,
+                }),
             }
-        };
-        res.push(HighlightedRange { range: node.text_range(), tag, binding_hash })
+        }
+        INT_NUMBER | FLOAT_NUMBER => tags::LITERAL_NUMERIC,
+        BYTE => tags::LITERAL_BYTE,
+        CHAR => tags::LITERAL_CHAR,
+        LIFETIME => tags::TYPE_LIFETIME,
+        T![unsafe] => tags::KEYWORD_UNSAFE,
+        k if is_control_keyword(k) => tags::KEYWORD_CONTROL,
+        k if k.is_keyword() => tags::KEYWORD,
+
+        _ => return None,
+    };
+
+    return Some((tag, binding_hash));
+
+    fn calc_binding_hash(file_id: HirFileId, name: &Name, shadow_count: u32) -> u64 {
+        fn hash<T: std::hash::Hash + std::fmt::Debug>(x: T) -> u64 {
+            use std::{collections::hash_map::DefaultHasher, hash::Hasher};
+
+            let mut hasher = DefaultHasher::new();
+            x.hash(&mut hasher);
+            hasher.finish()
+        }
+
+        hash((file_id, name, shadow_count))
     }
-    res
 }
 
 pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId, rainbow: bool) -> String {
@@ -331,6 +400,16 @@ fn foo<T>() -> T {
     foo::<i32>();
 }
 
+macro_rules! def_fn {
+    ($($tt:tt)*) => {$($tt)*}
+}
+
+def_fn!{
+    fn bar() -> u32 {
+        100
+    }
+}
+
 // comment
 fn main() {
     println!("Hello, {}!", 92);