3 files changed, 108 insertions, 38 deletions

diff --git a/crates/hir_def/src/nameres/tests.rs b/crates/hir_def/src/nameres/tests.rs
index 5ca30dac9..11d84f808 100644
--- a/crates/hir_def/src/nameres/tests.rs
+++ b/crates/hir_def/src/nameres/tests.rs
@@ -2,6 +2,7 @@ mod globs;
 mod incremental;
 mod macros;
 mod mod_resolution;
+mod diagnostics;
 mod primitives;
 
 use std::sync::Arc;
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
new file mode 100644
index 000000000..cd0eb1a4b
--- /dev/null
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -0,0 +1,107 @@
+use base_db::fixture::WithFixture;
+use base_db::FileId;
+use base_db::SourceDatabaseExt;
+use hir_expand::db::AstDatabase;
+use rustc_hash::FxHashMap;
+use syntax::TextRange;
+use syntax::TextSize;
+
+use crate::test_db::TestDB;
+
+fn check_diagnostics(ra_fixture: &str) {
+    let db: TestDB = TestDB::with_files(ra_fixture);
+    let annotations = db.extract_annotations();
+    assert!(!annotations.is_empty());
+
+    let mut actual: FxHashMap<FileId, Vec<(TextRange, String)>> = FxHashMap::default();
+    db.diagnostics(|d| {
+        let src = d.display_source();
+        let root = db.parse_or_expand(src.file_id).unwrap();
+        // FIXME: macros...
+        let file_id = src.file_id.original_file(&db);
+        let range = src.value.to_node(&root).text_range();
+        let message = d.message().to_owned();
+        actual.entry(file_id).or_default().push((range, message));
+    });
+
+    for (file_id, diags) in actual.iter_mut() {
+        diags.sort_by_key(|it| it.0.start());
+        let text = db.file_text(*file_id);
+        // For multiline spans, place them on line start
+        for (range, content) in diags {
+            if text[*range].contains('\n') {
+                *range = TextRange::new(range.start(), range.start() + TextSize::from(1));
+                *content = format!("... {}", content);
+            }
+        }
+    }
+
+    assert_eq!(annotations, actual);
+}
+
+#[test]
+fn unresolved_import() {
+    check_diagnostics(
+        r"
+        use does_exist;
+        use does_not_exist;
+          //^^^^^^^^^^^^^^ unresolved import
+
+        mod does_exist {}
+        ",
+    );
+}
+
+#[test]
+fn unresolved_import_in_use_tree() {
+    // Only the relevant part of a nested `use` item should be highlighted.
+    check_diagnostics(
+        r"
+        use does_exist::{Exists, DoesntExist};
+                               //^^^^^^^^^^^ unresolved import
+
+        use {does_not_exist::*, does_exist};
+           //^^^^^^^^^^^^^^^^^ unresolved import
+
+        use does_not_exist::{
+            a,
+          //^ unresolved import
+            b,
+          //^ unresolved import
+            c,
+          //^ unresolved import
+        };
+
+        mod does_exist {
+            pub struct Exists;
+        }
+        ",
+    );
+}
+
+#[test]
+fn unresolved_extern_crate() {
+    check_diagnostics(
+        r"
+        //- /main.rs crate:main deps:core
+        extern crate core;
+          extern crate doesnotexist;
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+        //- /lib.rs crate:core
+        ",
+    );
+}
+
+#[test]
+fn unresolved_module() {
+    check_diagnostics(
+        r"
+        //- /lib.rs
+        mod foo;
+          mod bar;
+        //^^^^^^^^ unresolved module
+        mod baz {}
+        //- /foo.rs
+        ",
+    );
+}
diff --git a/crates/hir_def/src/nameres/tests/mod_resolution.rs b/crates/hir_def/src/nameres/tests/mod_resolution.rs
index 3b9f79544..f93337a6e 100644
--- a/crates/hir_def/src/nameres/tests/mod_resolution.rs
+++ b/crates/hir_def/src/nameres/tests/mod_resolution.rs
@@ -672,44 +672,6 @@ pub struct Baz;
 }
 
 #[test]
-fn unresolved_module_diagnostics() {
-    let db = TestDB::with_files(
-        r"
-        //- /lib.rs
-        mod foo;
-        mod bar;
-        mod baz {}
-        //- /foo.rs
-        ",
-    );
-    let krate = db.test_crate();
-
-    let crate_def_map = db.crate_def_map(krate);
-
-    expect![[r#"
-        [
-            DefDiagnostic {
-                in_module: Idx::<ModuleData>(0),
-                kind: UnresolvedModule {
-                    declaration: InFile {
-                        file_id: HirFileId(
-                            FileId(
-                                FileId(
-                                    0,
-                                ),
-                            ),
-                        ),
-                        value: FileAstId::<syntax::ast::generated::nodes::Module>(1),
-                    },
-                    candidate: "bar.rs",
-                },
-            },
-        ]
-    "#]]
-    .assert_debug_eq(&crate_def_map.diagnostics);
-}
-
-#[test]
 fn module_resolution_decl_inside_module_in_non_crate_root_2() {
     check(
         r#"