Preserve courses with pending rooms and report precise graduate import errors

mobile/test/widgets/undergraduate_auth_test.dart

@@ -31,7 +31,7 @@ void main() {
     session.dispose();
     controller.dispose();
   });
-  Future<void> open(WidgetTester tester) async {
+  Future<void> open(WidgetTester tester, {String? timetableHtml}) async {
     controller = AppController(
       store,
       FakeNotifications(),
@@ -43,8 +43,9 @@ void main() {
     platform.web.javascript = (s) async => underEvidence(
       platform.web.url!,
       html: s == undergraduateCaptureScript
-          ? File('test/fixtures/school/undergraduate-timetable.html')
-                .readAsStringSync()
+          ? timetableHtml ??
+                File('test/fixtures/school/undergraduate-timetable.html')
+                    .readAsStringSync()
           : null,
     );
     platform.delegate.finished(platform.web.url!);
@@ -85,6 +86,21 @@ void main() {
     expect(find.text('打开'), findsOneWidget);
     SchoolPageDiagnostic.instance.clear();
   });
+  testWidgets('missing room imports with a visible pending-room notice', (
+    tester,
+  ) async {
+    await open(
+      tester,
+      timetableHtml: File('test/fixtures/school/undergraduate-timetable.html')
+          .readAsStringSync()
+          .replaceFirst('"教室1"', '""'),
+    );
+    await tester.tap(find.text('导入当前课表'));
+    await tester.pumpAndSettle();
+    expect(controller.snapshot.courses.any((c) => c.room == '教室待定'), isTrue);
+    expect(find.textContaining('部分课程教室待定'), findsOneWidget);
+    SchoolPageDiagnostic.instance.clear();
+  });
   testWidgets('cross school replacement can be cancelled without saving', (
     tester,
   ) async {