chore: add unit tests for app lifecycle

Author: AndrewAminInstabug

lib/src/utils/screen_rendering/instabug_screen_render_manager.dart

@@ -40,7 +40,7 @@ class InstabugScreenRenderManager {
 
   InstabugScreenRenderManager._();
 
-  static final InstabugScreenRenderManager _instance =
+  static  InstabugScreenRenderManager _instance =
       InstabugScreenRenderManager._();
 
   /// Returns the singleton instance of [InstabugScreenRenderManager].
@@ -53,10 +53,16 @@ class InstabugScreenRenderManager {
   static const tag = "ScreenRenderManager";
 
   /// A named constructor used for testing purposes
-
+  @internal
   @visibleForTesting
   InstabugScreenRenderManager.init();
 
+  /// Allows setting a custom instance for testing.
+  @visibleForTesting
+  // ignore: use_setters_to_change_properties
+  static void setInstance(InstabugScreenRenderManager instance) {
+    _instance = instance;
+  }
   /// setup function for [InstabugScreenRenderManager]
   @internal
   Future<void> init(WidgetsBinding widgetBinding) async {

test/utils/screen_render/instabug_widget_binding_observer_test.dart

@@ -0,0 +1,103 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:instabug_flutter/src/utils/screen_loading/screen_loading_manager.dart';
+import 'package:instabug_flutter/src/utils/screen_name_masker.dart';
+import 'package:instabug_flutter/src/utils/screen_rendering/instabug_screen_render_manager.dart';
+import 'package:instabug_flutter/src/utils/screen_rendering/instabug_widget_binding_observer.dart';
+import 'package:instabug_flutter/src/utils/ui_trace/ui_trace.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+
+import 'instabug_widget_binding_observer_test.mocks.dart';
+
+@GenerateMocks([
+  InstabugScreenRenderManager,
+  ScreenLoadingManager,
+  ScreenNameMasker,
+  UiTrace,
+])
+void main() {
+  late MockInstabugScreenRenderManager mockRenderManager;
+  late MockScreenLoadingManager mockLoadingManager;
+  late MockScreenNameMasker mockNameMasker;
+  late MockUiTrace mockUiTrace;
+
+  setUp(() {
+    mockRenderManager = MockInstabugScreenRenderManager();
+    mockLoadingManager = MockScreenLoadingManager();
+    mockNameMasker = MockScreenNameMasker();
+    mockUiTrace = MockUiTrace();
+
+    // Inject singleton mocks
+    InstabugScreenRenderManager.setInstance(mockRenderManager);
+    ScreenLoadingManager.setInstance(mockLoadingManager);
+    ScreenNameMasker.setInstance(mockNameMasker);
+  });
+
+  group('InstabugWidgetsBindingObserver', () {
+    test('returns the singleton instance', () {
+      final instance = InstabugWidgetsBindingObserver.instance;
+      final shorthand = InstabugWidgetsBindingObserver.I;
+      expect(instance, isA<InstabugWidgetsBindingObserver>());
+      expect(shorthand, same(instance));
+    });
+
+    test('handles AppLifecycleState.resumed and starts UiTrace', () async {
+      when(mockLoadingManager.currentUiTrace).thenReturn(mockUiTrace);
+      when(mockUiTrace.screenName).thenReturn("HomeScreen");
+      when(mockNameMasker.mask("HomeScreen")).thenReturn("MaskedHome");
+      when(mockLoadingManager.startUiTrace("MaskedHome", "HomeScreen"))
+          .thenAnswer((_) async => 123);
+
+      InstabugWidgetsBindingObserver.I
+          .didChangeAppLifecycleState(AppLifecycleState.resumed);
+
+      // wait for async call to complete
+      await untilCalled(
+          mockRenderManager.startScreenRenderCollectorForTraceId(123));
+
+      verify(mockRenderManager.startScreenRenderCollectorForTraceId(123))
+          .called(1);
+    });
+
+    test('handles AppLifecycleState.paused and stops render collector', () {
+      InstabugWidgetsBindingObserver.I
+          .didChangeAppLifecycleState(AppLifecycleState.paused);
+      verify(mockRenderManager.stopScreenRenderCollector()).called(1);
+    });
+
+    test('handles AppLifecycleState.detached and stops render collector', () {
+      InstabugWidgetsBindingObserver.I
+          .didChangeAppLifecycleState(AppLifecycleState.detached);
+      verify(mockRenderManager.stopScreenRenderCollector()).called(1);
+    });
+
+    test('handles AppLifecycleState.inactive with no action', () {
+      // Just ensure it doesn't crash
+      expect(() {
+        InstabugWidgetsBindingObserver.I
+            .didChangeAppLifecycleState(AppLifecycleState.inactive);
+      }, returnsNormally);
+    });
+
+    test('handles AppLifecycleState.hidden with no action', () {
+      expect(() {
+        InstabugWidgetsBindingObserver.I
+            .didChangeAppLifecycleState(AppLifecycleState.hidden);
+      }, returnsNormally);
+    });
+
+    test('_handleResumedState does nothing if no currentUiTrace', () {
+      when(mockLoadingManager.currentUiTrace).thenReturn(null);
+
+      InstabugWidgetsBindingObserver.I
+          .didChangeAppLifecycleState(AppLifecycleState.resumed);
+
+      verifyNever(mockRenderManager.startScreenRenderCollectorForTraceId(any));
+    });
+
+    test('checkForWidgetBinding ensures initialization', () {
+      expect(() => checkForWidgetBinding(), returnsNormally);
+    });
+  });
+}