default text if summary is null or empty (#5016)

Fix: flutter/flutter#184360

Author: ievdokdm

dashboard/lib/views/presubmit_view.dart

@@ -459,7 +459,9 @@ class _JobDetailsViewerPaneState extends State<_JobDetailsViewerPane> {
                 width: double.infinity,
                 child: SingleChildScrollView(
                   child: Text(
-                    selectedJob.summary ?? _getDefaultJobDetails(selectedJob),
+                    selectedJob.summary?.trim().isEmpty ?? true
+                        ? _getDefaultJobDetails(selectedJob)
+                        : selectedJob.summary!,
                     style: const TextStyle(
                       fontFamily: 'monospace',
                       fontSize: 13,
@@ -518,16 +520,16 @@ class _JobDetailsViewerPaneState extends State<_JobDetailsViewerPane> {
   String _getDefaultJobDetails(PresubmitJobResponse job) {
     return switch (job.status) {
       .succeeded =>
-        '${job.jobName} executed successfully.\nClick "View more details on LUCI UI" button bellow for more details.',
+        '${job.jobName} executed successfully.\nClick "View more details on LUCI UI" button below for more details.',
       .failed =>
-        '${job.jobName} failed.\nClick "View more details on LUCI UI" button bellow for more details.',
+        '${job.jobName} failed.\nClick "View more details on LUCI UI" button below for more details.',
       .infraFailure =>
-        'Infrastructure failed during execution of ${job.jobName}.\nClick "View more details on LUCI UI" button bellow for more details.',
+        'Infrastructure failed during execution of ${job.jobName}.\nClick "View more details on LUCI UI" button below for more details.',
       .skipped => '${job.jobName} is skipped.',
       .neutral => '${job.jobName} is disabled.',
       .cancelled => '${job.jobName} is cancelled.',
       .inProgress =>
-        '${job.jobName} is in progress.\nClick "View more details on LUCI UI" button bellow to see execution details.',
+        '${job.jobName} is in progress.\nClick "View more details on LUCI UI" button below to see execution details.',
       .waitingForBackfill =>
         '${job.jobName} is not yet scheduled for execution.\n"View more details on LUCI UI" button will become enabled once the job is scheduled.',
     };

dashboard/test/views/presubmit_view_test.dart

@@ -281,6 +281,83 @@ void main() {
     expect(find.textContaining('Status: Failed'), findsOneWidget);
   });
 
+  testWidgets('PreSubmitView displays default job details when summary is empty', (
+    WidgetTester tester,
+  ) async {
+    tester.view.physicalSize = const Size(2000, 1080);
+    tester.view.devicePixelRatio = 1.0;
+    addTearDown(tester.view.resetPhysicalSize);
+    addTearDown(tester.view.resetDevicePixelRatio);
+
+    const mockSha = 'decaf_3_real_sha';
+    const guardResponse = PresubmitGuardResponse(
+      prNum: 123,
+      author: 'dash',
+      guardStatus: GuardStatus.failed,
+      checkRunId: 456,
+      stages: [
+        PresubmitGuardStage(
+          name: 'Engine',
+          createdAt: 0,
+          builds: {'Mac mac_host_engine 1': TaskStatus.failed},
+        ),
+      ],
+    );
+
+    when(
+      mockCocoonService.fetchPresubmitGuard(
+        repo: anyNamed('repo'),
+        sha: mockSha,
+      ),
+    ).thenAnswer((_) async => const CocoonResponse.data(guardResponse));
+
+    when(
+      mockCocoonService.fetchPresubmitJobDetails(
+        checkRunId: anyNamed('checkRunId'),
+        jobName: argThat(contains('mac_host_engine'), named: 'jobName'),
+      ),
+    ).thenAnswer(
+      (_) async => CocoonResponse.data([
+        PresubmitJobResponse(
+          attemptNumber: 1,
+          jobName: 'Mac mac_host_engine 1',
+          creationTime: 0,
+          status: TaskStatus.failed,
+          summary: '', // Empty summary
+        ),
+      ]),
+    );
+
+    await tester.runAsync(() async {
+      await tester.pumpWidget(
+        createPreSubmitView({'repo': 'flutter', 'pr': '123'}),
+      );
+      for (var i = 0; i < 50; i++) {
+        await tester.pump();
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+        if (find.textContaining('by dash').evaluate().isNotEmpty) break;
+      }
+    });
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('PR #123'), findsOneWidget);
+
+    await tester.tap(find.textContaining('mac_host_engine').first);
+    await tester.runAsync(() async {
+      for (var i = 0; i < 50; i++) {
+        await tester.pump();
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+        if (find.textContaining('Mac mac_host_engine 1 failed.').evaluate().isNotEmpty) {
+          break;
+        }
+      }
+    });
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('Mac mac_host_engine 1 failed.'), findsOneWidget);
+    expect(find.textContaining('Click "View more details on LUCI UI" button below for more details.'), findsOneWidget);
+  });
+
   testWidgets(
     'PreSubmitView automatically selects latest SHA and updates sidebar when opened with PR only',
     (WidgetTester tester) async {