refactor: Update color opacity application to withValues(alpha:) and refine test variable declarations and Future types.

Author: ievdokdm

dashboard/lib/widgets/guard_status.dart

@@ -30,9 +30,9 @@ class GuardStatus extends StatelessWidget {
         vertical: isDense ? 1 : 2,
       ),
       decoration: BoxDecoration(
-        color: statusColor.withOpacity(0.1),
+        color: statusColor.withValues(alpha: 0.1),
         borderRadius: BorderRadius.circular(12),
-        border: Border.all(color: statusColor.withOpacity(0.2)),
+        border: Border.all(color: statusColor.withValues(alpha: 0.2)),
       ),
       child: showText
           ? Text(

dashboard/test/state/presubmit_test.dart

@@ -63,7 +63,7 @@ void main() {
   test(
     'PresubmitState update method updates properties and notifies listeners',
     () {
-      bool notified = false;
+      var notified = false;
       presubmitState.addListener(() => notified = true);
 
       presubmitState.update(repo: 'cocoon', pr: '123', sha: 'abc');
@@ -96,7 +96,7 @@ void main() {
       );
 
       presubmitState.pr = '123';
-      bool notified = false;
+      var notified = false;
       presubmitState.addListener(() => notified = true);
 
       await presubmitState.fetchAvailableShas();
@@ -124,7 +124,7 @@ void main() {
       );
 
       presubmitState.sha = 'sha1';
-      bool notified = false;
+      var notified = false;
       presubmitState.addListener(() => notified = true);
 
       await presubmitState.fetchGuardStatus();
@@ -144,7 +144,7 @@ void main() {
       // Use update to stabilize the state including lastFetched flags
       presubmitState.update(repo: 'flutter', pr: '123', sha: 'abc');
 
-      bool notified = false;
+      var notified = false;
       presubmitState.addListener(() => notified = true);
 
       presubmitState.update(repo: 'flutter', pr: '123', sha: 'abc');

dashboard/test/views/presubmit_view_test.dart

@@ -153,7 +153,7 @@ void main() {
         );
         for (var i = 0; i < 50; i++) {
           await tester.pump();
-          await Future.delayed(const Duration(milliseconds: 50));
+          await Future<void>.delayed(const Duration(milliseconds: 50));
           if (find.textContaining('by dash').evaluate().isNotEmpty) break;
         }
       });
@@ -224,7 +224,7 @@ void main() {
       );
       for (var i = 0; i < 50; i++) {
         await tester.pump();
-        await Future.delayed(const Duration(milliseconds: 50));
+        await Future<void>.delayed(const Duration(milliseconds: 50));
         if (find.textContaining('by dash').evaluate().isNotEmpty) break;
       }
     });
@@ -236,7 +236,7 @@ void main() {
     await tester.runAsync(() async {
       for (var i = 0; i < 50; i++) {
         await tester.pump();
-        await Future.delayed(const Duration(milliseconds: 50));
+        await Future<void>.delayed(const Duration(milliseconds: 50));
         if (find.textContaining('All tests passed').evaluate().isNotEmpty) {
           break;
         }
@@ -291,7 +291,7 @@ void main() {
         // Wait for summaries, then latest SHA selection, then guard status fetch
         for (var i = 0; i < 50; i++) {
           await tester.pump();
-          await Future.delayed(const Duration(milliseconds: 50));
+          await Future<void>.delayed(const Duration(milliseconds: 50));
           final state = Provider.of<PresubmitState>(
             tester.element(find.byType(PreSubmitView)),
             listen: false,
@@ -325,7 +325,7 @@ void main() {
       );
       for (var i = 0; i < 20; i++) {
         await tester.pump();
-        await Future.delayed(const Duration(milliseconds: 50));
+        await Future<void>.delayed(const Duration(milliseconds: 50));
         if (find.byType(ShaSelector).evaluate().isNotEmpty) break;
       }
     });
@@ -400,7 +400,7 @@ void main() {
       );
       for (var i = 0; i < 20; i++) {
         await tester.pump();
-        await Future.delayed(const Duration(milliseconds: 50));
+        await Future<void>.delayed(const Duration(milliseconds: 50));
         if (find.textContaining('by dash').evaluate().isNotEmpty) break;
       }
     });
@@ -410,9 +410,10 @@ void main() {
     await tester.runAsync(() async {
       for (var i = 0; i < 20; i++) {
         await tester.pump();
-        await Future.delayed(const Duration(milliseconds: 50));
-        if (find.textContaining('Live log content').evaluate().isNotEmpty)
+        await Future<void>.delayed(const Duration(milliseconds: 50));
+        if (find.textContaining('Live log content').evaluate().isNotEmpty) {
           break;
+        }
       }
     });
     await tester.pumpAndSettle();
@@ -509,7 +510,7 @@ void main() {
         );
         for (var i = 0; i < 20; i++) {
           await tester.pump();
-          await Future.delayed(const Duration(milliseconds: 50));
+          await Future<void>.delayed(const Duration(milliseconds: 50));
           if (find.textContaining('by dash').evaluate().isNotEmpty) break;
         }
       });