1 files changed, 101 insertions, 0 deletions

diff --git a/crates/hir_def/src/test_db.rs b/crates/hir_def/src/test_db.rs
new file mode 100644
index 000000000..42a762936
--- /dev/null
+++ b/crates/hir_def/src/test_db.rs
@@ -0,0 +1,101 @@
+//! Database used for testing `hir_def`.
+
+use std::{
+    fmt, panic,
+    sync::{Arc, Mutex},
+};
+
+use base_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, Upcast};
+use hir_expand::db::AstDatabase;
+use rustc_hash::FxHashSet;
+
+use crate::db::DefDatabase;
+
+#[salsa::database(
+    base_db::SourceDatabaseExtStorage,
+    base_db::SourceDatabaseStorage,
+    hir_expand::db::AstDatabaseStorage,
+    crate::db::InternDatabaseStorage,
+    crate::db::DefDatabaseStorage
+)]
+#[derive(Default)]
+pub struct TestDB {
+    storage: salsa::Storage<TestDB>,
+    events: Mutex<Option<Vec<salsa::Event>>>,
+}
+
+impl Upcast<dyn AstDatabase> for TestDB {
+    fn upcast(&self) -> &(dyn AstDatabase + 'static) {
+        &*self
+    }
+}
+
+impl Upcast<dyn DefDatabase> for TestDB {
+    fn upcast(&self) -> &(dyn DefDatabase + 'static) {
+        &*self
+    }
+}
+
+impl salsa::Database for TestDB {
+    fn salsa_event(&self, event: salsa::Event) {
+        let mut events = self.events.lock().unwrap();
+        if let Some(events) = &mut *events {
+            events.push(event);
+        }
+    }
+}
+
+impl fmt::Debug for TestDB {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TestDB").finish()
+    }
+}
+
+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_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
+    }
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
+        FileLoaderDelegate(self).relevant_crates(file_id)
+    }
+}
+
+impl TestDB {
+    pub fn module_for_file(&self, file_id: FileId) -> crate::ModuleId {
+        for &krate in self.relevant_crates(file_id).iter() {
+            let crate_def_map = self.crate_def_map(krate);
+            for (local_id, data) in crate_def_map.modules.iter() {
+                if data.origin.file_id() == Some(file_id) {
+                    return crate::ModuleId { krate, local_id };
+                }
+            }
+        }
+        panic!("Can't find module for file")
+    }
+
+    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
+        *self.events.lock().unwrap() = Some(Vec::new());
+        f();
+        self.events.lock().unwrap().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.debug(self)))
+                }
+                _ => None,
+            })
+            .collect()
+    }
+}