8 files changed, 212 insertions, 306 deletions

diff --git a/crates/ra_assists/src/doc_tests.rs b/crates/ra_assists/src/doc_tests.rs
index 6e1e3de84..a8f8446cb 100644
--- a/crates/ra_assists/src/doc_tests.rs
+++ b/crates/ra_assists/src/doc_tests.rs
@@ -5,13 +5,14 @@
 
 mod generated;
 
-use hir::mock::MockDatabase;
-use ra_db::FileRange;
+use ra_db::{fixture::WithFixture, FileRange};
 use test_utils::{assert_eq_text, extract_range_or_offset};
 
+use crate::test_db::TestDB;
+
 fn check(assist_id: &str, before: &str, after: &str) {
     let (selection, before) = extract_range_or_offset(before);
-    let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+    let (db, file_id) = TestDB::with_single_file(&before);
     let frange = FileRange { file_id, range: selection.into() };
 
     let (_assist_id, action) = crate::assists(&db, frange)
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 38599d4f1..39c1c283f 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -9,6 +9,8 @@ mod assist_ctx;
 mod marks;
 #[cfg(test)]
 mod doc_tests;
+#[cfg(test)]
+mod test_db;
 
 use hir::db::HirDatabase;
 use ra_db::FileRange;
@@ -146,20 +148,19 @@ mod assists {
 
 #[cfg(test)]
 mod helpers {
-    use hir::mock::MockDatabase;
-    use ra_db::FileRange;
+    use ra_db::{fixture::WithFixture, FileRange};
     use ra_syntax::TextRange;
     use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
 
-    use crate::{Assist, AssistCtx};
+    use crate::{test_db::TestDB, Assist, AssistCtx};
 
     pub(crate) fn check_assist(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
         after: &str,
     ) {
         let (before_cursor_pos, before) = extract_offset(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange =
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assist =
@@ -182,12 +183,12 @@ mod helpers {
     }
 
     pub(crate) fn check_assist_range(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
         after: &str,
     ) {
         let (range, before) = extract_range(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange = FileRange { file_id, range };
         let assist =
             AssistCtx::with_ctx(&db, frange, true, assist).expect("code action is not applicable");
@@ -204,12 +205,12 @@ mod helpers {
     }
 
     pub(crate) fn check_assist_target(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
         target: &str,
     ) {
         let (before_cursor_pos, before) = extract_offset(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange =
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assist =
@@ -224,12 +225,12 @@ mod helpers {
     }
 
     pub(crate) fn check_assist_range_target(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
         target: &str,
     ) {
         let (range, before) = extract_range(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange = FileRange { file_id, range };
         let assist =
             AssistCtx::with_ctx(&db, frange, true, assist).expect("code action is not applicable");
@@ -243,11 +244,11 @@ mod helpers {
     }
 
     pub(crate) fn check_assist_not_applicable(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
     ) {
         let (before_cursor_pos, before) = extract_offset(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange =
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assist = AssistCtx::with_ctx(&db, frange, true, assist);
@@ -255,11 +256,11 @@ mod helpers {
     }
 
     pub(crate) fn check_assist_range_not_applicable(
-        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
+        assist: fn(AssistCtx<TestDB>) -> Option<Assist>,
         before: &str,
     ) {
         let (range, before) = extract_range(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange = FileRange { file_id, range };
         let assist = AssistCtx::with_ctx(&db, frange, true, assist);
         assert!(assist.is_none());
@@ -268,16 +269,17 @@ mod helpers {
 
 #[cfg(test)]
 mod tests {
-    use hir::mock::MockDatabase;
-    use ra_db::FileRange;
+    use ra_db::{fixture::WithFixture, FileRange};
     use ra_syntax::TextRange;
     use test_utils::{extract_offset, extract_range};
 
+    use crate::test_db::TestDB;
+
     #[test]
     fn assist_order_field_struct() {
         let before = "struct Foo { <|>bar: u32 }";
         let (before_cursor_pos, before) = extract_offset(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange =
             FileRange { file_id, range: TextRange::offset_len(before_cursor_pos, 0.into()) };
         let assists = super::assists(&db, frange);
@@ -298,7 +300,7 @@ mod tests {
             }
         }";
         let (range, before) = extract_range(before);
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+        let (db, file_id) = TestDB::with_single_file(&before);
         let frange = FileRange { file_id, range };
         let assists = super::assists(&db, frange);
         let mut assists = assists.iter();
diff --git a/crates/ra_assists/src/test_db.rs b/crates/ra_assists/src/test_db.rs
new file mode 100644
index 000000000..5be7383ed
--- /dev/null
+++ b/crates/ra_assists/src/test_db.rs
@@ -0,0 +1,45 @@
+//! Database used for testing `ra_assists`.
+
+use std::sync::Arc;
+
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath};
+
+#[salsa::database(
+    ra_db::SourceDatabaseExtStorage,
+    ra_db::SourceDatabaseStorage,
+    hir::db::InternDatabaseStorage,
+    hir::db::AstDatabaseStorage,
+    hir::db::DefDatabaseStorage,
+    hir::db::DefDatabase2Storage,
+    hir::db::HirDatabaseStorage
+)]
+#[derive(Debug, Default)]
+pub struct TestDB {
+    runtime: salsa::Runtime<TestDB>,
+}
+
+impl salsa::Database for TestDB {
+    fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
+        &self.runtime
+    }
+}
+
+impl std::panic::RefUnwindSafe for TestDB {}
+
+impl FileLoader for TestDB {
+    fn file_text(&self, file_id: FileId) -> Arc<String> {
+        FileLoaderDelegate(self).file_text(file_id)
+    }
+    fn resolve_relative_path(
+        &self,
+        anchor: FileId,
+        relative_path: &RelativePath,
+    ) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    }
+    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+        FileLoaderDelegate(self).relevant_crates(file_id)
+    }
+}
+
+impl hir::debug::HirDebugHelper for TestDB {}
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index 5496822e7..c14c2ab66 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -174,11 +174,11 @@ fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope
 
 #[cfg(test)]
 mod tests {
-    use ra_db::SourceDatabase;
+    use ra_db::{fixture::WithFixture, SourceDatabase};
     use ra_syntax::{algo::find_node_at_offset, ast, AstNode};
     use test_utils::{assert_eq_text, extract_offset};
 
-    use crate::{mock::MockDatabase, source_binder::SourceAnalyzer};
+    use crate::{source_binder::SourceAnalyzer, test_db::TestDB};
 
     fn do_check(code: &str, expected: &[&str]) {
         let (off, code) = extract_offset(code);
@@ -191,7 +191,7 @@ mod tests {
             buf
         };
 
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&code);
+        let (db, file_id) = TestDB::with_single_file(&code);
         let file = db.parse(file_id).ok().unwrap();
         let marker: ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
         let analyzer = SourceAnalyzer::new(&db, file_id, marker.syntax(), None);
@@ -288,7 +288,7 @@ mod tests {
     fn do_check_local_name(code: &str, expected_offset: u32) {
         let (off, code) = extract_offset(code);
 
-        let (db, _source_root, file_id) = MockDatabase::with_single_file(&code);
+        let (db, file_id) = TestDB::with_single_file(&code);
         let file = db.parse(file_id).ok().unwrap();
         let expected_name = find_node_at_offset::<ast::Name>(file.syntax(), expected_offset.into())
             .expect("failed to find a name at the target offset");
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3ba99d92d..da6aa2ed8 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -29,8 +29,6 @@ macro_rules! impl_froms {
 pub mod debug;
 
 pub mod db;
-#[macro_use]
-pub mod mock;
 pub mod source_binder;
 
 mod ids;
@@ -52,6 +50,8 @@ mod code_model;
 pub mod from_source;
 
 #[cfg(test)]
+mod test_db;
+#[cfg(test)]
 mod marks;
 
 use hir_expand::AstId;
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
deleted file mode 100644
index ab97a09b9..000000000
--- a/crates/ra_hir/src/mock.rs
+++ /dev/null
@@ -1,262 +0,0 @@
-//! FIXME: write short doc here
-
-use std::{panic, sync::Arc};
-
-use hir_expand::diagnostics::DiagnosticSink;
-use parking_lot::Mutex;
-use ra_cfg::CfgOptions;
-use ra_db::{
-    salsa, CrateGraph, CrateId, Edition, FileId, FileLoader, FileLoaderDelegate, FilePosition,
-    RelativePath, RelativePathBuf, SourceDatabase, SourceDatabaseExt, SourceRoot, SourceRootId,
-};
-use rustc_hash::FxHashMap;
-use test_utils::{extract_offset, parse_fixture, CURSOR_MARKER};
-
-use crate::{db, debug::HirDebugHelper};
-
-pub const WORKSPACE: SourceRootId = SourceRootId(0);
-
-#[salsa::database(
-    ra_db::SourceDatabaseExtStorage,
-    ra_db::SourceDatabaseStorage,
-    db::InternDatabaseStorage,
-    db::AstDatabaseStorage,
-    db::DefDatabaseStorage,
-    db::DefDatabase2Storage,
-    db::HirDatabaseStorage
-)]
-#[derive(Debug)]
-pub struct MockDatabase {
-    events: Mutex<Option<Vec<salsa::Event<MockDatabase>>>>,
-    runtime: salsa::Runtime<MockDatabase>,
-    files: FxHashMap<String, FileId>,
-    crate_names: Arc<FxHashMap<CrateId, String>>,
-    file_paths: Arc<FxHashMap<FileId, String>>,
-}
-
-impl panic::RefUnwindSafe for MockDatabase {}
-
-impl FileLoader for MockDatabase {
-    fn file_text(&self, file_id: FileId) -> Arc<String> {
-        FileLoaderDelegate(self).file_text(file_id)
-    }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
-    }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
-        FileLoaderDelegate(self).relevant_crates(file_id)
-    }
-}
-
-impl HirDebugHelper for MockDatabase {
-    fn crate_name(&self, krate: CrateId) -> Option<String> {
-        self.crate_names.get(&krate).cloned()
-    }
-
-    fn file_path(&self, file_id: FileId) -> Option<String> {
-        self.file_paths.get(&file_id).cloned()
-    }
-}
-
-impl MockDatabase {
-    pub fn with_files(fixture: &str) -> MockDatabase {
-        let (db, position) = MockDatabase::from_fixture(fixture);
-        assert!(position.is_none());
-        db
-    }
-
-    pub fn with_single_file(text: &str) -> (MockDatabase, SourceRoot, FileId) {
-        let mut db = MockDatabase::default();
-        let mut source_root = SourceRoot::default();
-        let file_id = db.add_file(WORKSPACE, "/", &mut source_root, "/main.rs", text);
-        db.set_source_root(WORKSPACE, Arc::new(source_root.clone()));
-        (db, source_root, file_id)
-    }
-
-    pub fn file_id_of(&self, path: &str) -> FileId {
-        match self.files.get(path) {
-            Some(it) => *it,
-            None => panic!("unknown file: {:?}\nexisting files:\n{:#?}", path, self.files),
-        }
-    }
-
-    pub fn diagnostics(&self) -> String {
-        let mut buf = String::new();
-        let mut files: Vec<FileId> = self.files.values().copied().collect();
-        files.sort();
-        for file in files {
-            let src = crate::Source {
-                file_id: file.into(),
-                ast: crate::ModuleSource::new(self, Some(file), None),
-            };
-            let module = crate::Module::from_definition(self, src).unwrap();
-            module.diagnostics(
-                self,
-                &mut DiagnosticSink::new(|d| {
-                    buf += &format!("{:?}: {}\n", d.syntax_node(self).text(), d.message());
-                }),
-            )
-        }
-        buf
-    }
-
-    fn from_fixture(fixture: &str) -> (MockDatabase, Option<FilePosition>) {
-        let mut db = MockDatabase::default();
-
-        let pos = db.add_fixture(fixture);
-
-        (db, pos)
-    }
-
-    fn add_fixture(&mut self, fixture: &str) -> Option<FilePosition> {
-        let mut position = None;
-        let mut source_root = SourceRoot::default();
-        let mut source_root_id = WORKSPACE;
-        let mut source_root_prefix = "/".to_string();
-        for entry in parse_fixture(fixture) {
-            if entry.meta.starts_with("root") {
-                self.set_source_root(source_root_id, Arc::new(source_root));
-                source_root = SourceRoot::default();
-
-                source_root_id = SourceRootId(source_root_id.0 + 1);
-                source_root_prefix = entry.meta["root".len()..].trim().to_string();
-                continue;
-            }
-            if entry.text.contains(CURSOR_MARKER) {
-                assert!(position.is_none(), "only one marker (<|>) per fixture is allowed");
-                position = Some(self.add_file_with_position(
-                    source_root_id,
-                    &source_root_prefix,
-                    &mut source_root,
-                    &entry.meta,
-                    &entry.text,
-                ));
-            } else {
-                self.add_file(
-                    source_root_id,
-                    &source_root_prefix,
-                    &mut source_root,
-                    &entry.meta,
-                    &entry.text,
-                );
-            }
-        }
-        self.set_source_root(source_root_id, Arc::new(source_root));
-        position
-    }
-
-    fn add_file(
-        &mut self,
-        source_root_id: SourceRootId,
-        source_root_prefix: &str,
-        source_root: &mut SourceRoot,
-        path: &str,
-        text: &str,
-    ) -> FileId {
-        assert!(source_root_prefix.starts_with('/'));
-        assert!(source_root_prefix.ends_with('/'));
-        assert!(path.starts_with(source_root_prefix));
-        let rel_path = RelativePathBuf::from_path(&path[source_root_prefix.len()..]).unwrap();
-
-        let is_crate_root = rel_path == "lib.rs" || rel_path == "/main.rs";
-
-        let file_id = FileId(self.files.len() as u32);
-
-        let prev = self.files.insert(path.to_string(), file_id);
-        assert!(prev.is_none(), "duplicate files in the text fixture");
-        Arc::make_mut(&mut self.file_paths).insert(file_id, path.to_string());
-
-        let text = Arc::new(text.to_string());
-        self.set_file_text(file_id, text);
-        self.set_file_relative_path(file_id, rel_path.clone());
-        self.set_file_source_root(file_id, source_root_id);
-        source_root.insert_file(rel_path, file_id);
-
-        if is_crate_root {
-            let mut crate_graph = CrateGraph::default();
-            crate_graph.add_crate_root(file_id, Edition::Edition2018, CfgOptions::default());
-            self.set_crate_graph(Arc::new(crate_graph));
-        }
-        file_id
-    }
-
-    fn add_file_with_position(
-        &mut self,
-        source_root_id: SourceRootId,
-        source_root_prefix: &str,
-        source_root: &mut SourceRoot,
-        path: &str,
-        text: &str,
-    ) -> FilePosition {
-        let (offset, text) = extract_offset(text);
-        let file_id = self.add_file(source_root_id, source_root_prefix, source_root, path, &text);
-        FilePosition { file_id, offset }
-    }
-}
-
-impl salsa::Database for MockDatabase {
-    fn salsa_runtime(&self) -> &salsa::Runtime<MockDatabase> {
-        &self.runtime
-    }
-
-    fn salsa_event(&self, event: impl Fn() -> salsa::Event<MockDatabase>) {
-        let mut events = self.events.lock();
-        if let Some(events) = &mut *events {
-            events.push(event());
-        }
-    }
-}
-
-impl Default for MockDatabase {
-    fn default() -> MockDatabase {
-        let mut db = MockDatabase {
-            events: Default::default(),
-            runtime: salsa::Runtime::default(),
-            files: FxHashMap::default(),
-            crate_names: Default::default(),
-            file_paths: Default::default(),
-        };
-        db.set_crate_graph(Default::default());
-        db
-    }
-}
-
-impl salsa::ParallelDatabase for MockDatabase {
-    fn snapshot(&self) -> salsa::Snapshot<MockDatabase> {
-        salsa::Snapshot::new(MockDatabase {
-            events: Default::default(),
-            runtime: self.runtime.snapshot(self),
-            // only the root database can be used to get file_id by path.
-            files: FxHashMap::default(),
-            file_paths: Arc::clone(&self.file_paths),
-            crate_names: Arc::clone(&self.crate_names),
-        })
-    }
-}
-
-impl MockDatabase {
-    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event<MockDatabase>> {
-        *self.events.lock() = Some(Vec::new());
-        f();
-        self.events.lock().take().unwrap()
-    }
-
-    pub fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
-        let events = self.log(f);
-        events
-            .into_iter()
-            .filter_map(|e| match e.kind {
-                // This pretty horrible, but `Debug` is the only way to inspect
-                // QueryDescriptor at the moment.
-                salsa::EventKind::WillExecute { database_key } => {
-                    Some(format!("{:?}", database_key))
-                }
-                _ => None,
-            })
-            .collect()
-    }
-}
diff --git a/crates/ra_hir/src/test_db.rs b/crates/ra_hir/src/test_db.rs
new file mode 100644
index 000000000..5237b303a
--- /dev/null
+++ b/crates/ra_hir/src/test_db.rs
@@ -0,0 +1,120 @@
+//! Database used for testing `hir`.
+
+use std::{panic, sync::Arc};
+
+use hir_def::{db::DefDatabase2, ModuleId};
+use hir_expand::diagnostics::DiagnosticSink;
+use parking_lot::Mutex;
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath, SourceDatabase};
+
+use crate::{db, debug::HirDebugHelper};
+
+#[salsa::database(
+    ra_db::SourceDatabaseExtStorage,
+    ra_db::SourceDatabaseStorage,
+    db::InternDatabaseStorage,
+    db::AstDatabaseStorage,
+    db::DefDatabaseStorage,
+    db::DefDatabase2Storage,
+    db::HirDatabaseStorage
+)]
+#[derive(Debug, Default)]
+pub struct TestDB {
+    events: Mutex<Option<Vec<salsa::Event<TestDB>>>>,
+    runtime: salsa::Runtime<TestDB>,
+}
+
+impl salsa::Database for TestDB {
+    fn salsa_runtime(&self) -> &salsa::Runtime<TestDB> {
+        &self.runtime
+    }
+
+    fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
+        let mut events = self.events.lock();
+        if let Some(events) = &mut *events {
+            events.push(event());
+        }
+    }
+}
+
+impl salsa::ParallelDatabase for TestDB {
+    fn snapshot(&self) -> salsa::Snapshot<TestDB> {
+        salsa::Snapshot::new(TestDB {
+            events: Default::default(),
+            runtime: self.runtime.snapshot(self),
+        })
+    }
+}
+
+impl panic::RefUnwindSafe for TestDB {}
+
+impl FileLoader for TestDB {
+    fn file_text(&self, file_id: FileId) -> Arc<String> {
+        FileLoaderDelegate(self).file_text(file_id)
+    }
+    fn resolve_relative_path(
+        &self,
+        anchor: FileId,
+        relative_path: &RelativePath,
+    ) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    }
+    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+        FileLoaderDelegate(self).relevant_crates(file_id)
+    }
+}
+
+// FIXME: improve `WithFixture` to bring useful hir debugging back
+impl HirDebugHelper for TestDB {
+    fn crate_name(&self, _krate: CrateId) -> Option<String> {
+        None
+    }
+
+    fn file_path(&self, _file_id: FileId) -> Option<String> {
+        None
+    }
+}
+
+impl TestDB {
+    pub fn diagnostics(&self) -> String {
+        let mut buf = String::new();
+        let crate_graph = self.crate_graph();
+        for krate in crate_graph.iter().next() {
+            let crate_def_map = self.crate_def_map(krate);
+            for (module_id, _) in crate_def_map.modules.iter() {
+                let module_id = ModuleId { krate, module_id };
+                let module = crate::Module::from(module_id);
+                module.diagnostics(
+                    self,
+                    &mut DiagnosticSink::new(|d| {
+                        buf += &format!("{:?}: {}\n", d.syntax_node(self).text(), d.message());
+                    }),
+                )
+            }
+        }
+        buf
+    }
+}
+
+impl TestDB {
+    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event<TestDB>> {
+        *self.events.lock() = Some(Vec::new());
+        f();
+        self.events.lock().take().unwrap()
+    }
+
+    pub fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
+        let events = self.log(f);
+        events
+            .into_iter()
+            .filter_map(|e| match e.kind {
+                // This pretty horrible, but `Debug` is the only way to inspect
+                // QueryDescriptor at the moment.
+                salsa::EventKind::WillExecute { database_key } => {
+                    Some(format!("{:?}", database_key))
+                }
+                _ => None,
+            })
+            .collect()
+    }
+}
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 4b7e34878..e56b9356e 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
 use test_utils::covers;
 
 use crate::{
-    expr::BodySourceMap, mock::MockDatabase, ty::display::HirDisplay, ty::InferenceResult,
+    expr::BodySourceMap, test_db::TestDB, ty::display::HirDisplay, ty::InferenceResult,
     SourceAnalyzer,
 };
 
@@ -24,7 +24,7 @@ mod coercion;
 
 #[test]
 fn cfg_impl_block() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:foo cfg:test
 use foo::S as T;
@@ -64,7 +64,7 @@ impl S {
 
 #[test]
 fn infer_await() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:std
 
@@ -95,7 +95,7 @@ mod future {
 
 #[test]
 fn infer_box() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:std
 
@@ -122,7 +122,7 @@ mod boxed {
 
 #[test]
 fn infer_adt_self() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs
 enum Nat { Succ(Self), Demo(Nat), Zero }
@@ -141,7 +141,7 @@ fn test() {
 
 #[test]
 fn infer_try() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:std
 
@@ -181,7 +181,7 @@ mod result {
 
 #[test]
 fn infer_for_loop() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:std
 
@@ -223,7 +223,7 @@ mod collections {
 #[test]
 fn infer_while_let() {
     covers!(infer_while_let);
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs
 enum Option<T> { Some(T), None }
@@ -2484,7 +2484,7 @@ pub fn main_loop() {
 
 #[test]
 fn cross_crate_associated_method_call() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:other_crate
 fn test() {
@@ -3378,7 +3378,7 @@ fn test() { S.foo()<|>; }
 
 #[test]
 fn infer_macro_with_dollar_crate_is_correct_in_expr() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:foo
 fn test() {
@@ -3482,7 +3482,7 @@ fn test() { (&S).foo()<|>; }
 
 #[test]
 fn method_resolution_trait_from_prelude() {
-    let (db, pos) = MockDatabase::with_position(
+    let (db, pos) = TestDB::with_position(
         r#"
 //- /main.rs crate:main deps:other_crate
 struct S;
@@ -4651,7 +4651,7 @@ fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
     assert_eq!(t, "{unknown}");
 }
 
-fn type_at_pos(db: &MockDatabase, pos: FilePosition) -> String {
+fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
     let analyzer = SourceAnalyzer::new(db, pos.file_id, expr.syntax(), Some(pos.offset));
@@ -4660,12 +4660,12 @@ fn type_at_pos(db: &MockDatabase, pos: FilePosition) -> String {
 }
 
 fn type_at(content: &str) -> String {
-    let (db, file_pos) = MockDatabase::with_position(content);
+    let (db, file_pos) = TestDB::with_position(content);
     type_at_pos(&db, file_pos)
 }
 
 fn infer(content: &str) -> String {
-    let (db, _, file_id) = MockDatabase::with_single_file(content);
+    let (db, file_id) = TestDB::with_single_file(content);
     let source_file = db.parse(file_id).ok().unwrap();
 
     let mut acc = String::new();
@@ -4748,7 +4748,7 @@ fn ellipsize(mut text: String, max_len: usize) -> String {
 
 #[test]
 fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
-    let (mut db, pos) = MockDatabase::with_position(
+    let (mut db, pos) = TestDB::with_position(
         "
         //- /lib.rs
         fn foo() -> i32 {
@@ -4788,7 +4788,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
 
 #[test]
 fn no_such_field_diagnostics() {
-    let diagnostics = MockDatabase::with_files(
+    let diagnostics = TestDB::with_files(
         r"
         //- /lib.rs
         struct S { foo: i32, bar: () }