[tizen_audio_manager] Add regression integration tests (#1050)

Author: seungsoo47

packages/tizen_audio_manager/CHANGELOG.md

@@ -5,6 +5,7 @@
 * Update code format.
 * Add a 3-second delay in integration_test to support the media volume reset
   feature of the Tizen Volume app for hearing protection.
+* Add 2 integration test cases.
 
 ## 0.1.1
 

packages/tizen_audio_manager/example/integration_test/audio_manager_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 import 'package:tizen_audio_manager/tizen_audio_manager.dart';
@@ -204,4 +206,44 @@ void main() {
     level = await AudioManager.volumeController.getLevel(AudioVolumeType.voip);
     expect(level, equals(0));
   });
+
+  testWidgets('currentPlaybackType returns a valid AudioVolumeType',
+      (WidgetTester tester) async {
+    final AudioVolumeType type =
+        await AudioManager.volumeController.currentPlaybackType;
+    expect(AudioVolumeType.values, contains(type));
+  });
+
+  testWidgets('onChanged emits VolumeChangedEvent when volume is changed',
+      (WidgetTester tester) async {
+    final int originalLevel =
+        await AudioManager.volumeController.getLevel(AudioVolumeType.system);
+    final int maxLevel =
+        await AudioManager.volumeController.getMaxLevel(AudioVolumeType.system);
+    final int targetLevel = originalLevel == maxLevel ? 0 : maxLevel;
+
+    final Completer<VolumeChangedEvent> completer =
+        Completer<VolumeChangedEvent>();
+    final StreamSubscription<VolumeChangedEvent> subscription = AudioManager
+        .volumeController.onChanged
+        .listen((VolumeChangedEvent event) {
+      if (event.type == AudioVolumeType.system && !completer.isCompleted) {
+        completer.complete(event);
+      }
+    });
+
+    try {
+      await AudioManager.volumeController
+          .setLevel(AudioVolumeType.system, targetLevel);
+      final VolumeChangedEvent event =
+          await completer.future.timeout(const Duration(seconds: 5));
+
+      expect(event.type, equals(AudioVolumeType.system));
+      expect(event.level, equals(targetLevel));
+    } finally {
+      await AudioManager.volumeController
+          .setLevel(AudioVolumeType.system, originalLevel);
+      await subscription.cancel();
+    }
+  });
 }