feat: transition mixin doc and coverage

lib/home/widgets/question_view.dart

@@ -24,6 +24,8 @@ class _QuestionViewState extends State<QuestionView>
 
   @override
   void initializeTransitionController() {
+    super.initializeTransitionController();
+
     enterTransitionController = AnimationController(
       vsync: this,
       duration: const Duration(seconds: 1),

lib/home/widgets/thinking_view.dart

@@ -24,6 +24,8 @@ class _ThinkingViewState extends State<ThinkingView>
 
   @override
   void initializeTransitionController() {
+    super.initializeTransitionController();
+
     enterTransitionController = AnimationController(
       vsync: this,
       duration: const Duration(seconds: 1),

lib/home/widgets/transition_screen_mixin.dart

@@ -2,25 +2,33 @@ import 'package:dash_ai_search/home/home.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
+/// Mixin to handle transitions between screens.
 mixin TransitionScreenMixin<T extends StatefulWidget> on State<T> {
+  /// The [AnimationController] for the enter transition.
   @protected
   late AnimationController enterTransitionController;
 
+  /// The [AnimationController] for the exit transition.
   @protected
   late AnimationController exitTransitionController;
 
+  /// The [Status]es that trigger the forward enter transition.
   @protected
   List<Status> forwardEnterStatuses = [];
 
+  /// The [Status]es that trigger the forward exit transition.
   @protected
   List<Status> forwardExitStatuses = [];
 
+  /// The [Status]es that trigger the back enter transition.
   @protected
   List<Status> backEnterStatuses = [];
 
+  /// The [Status]es that trigger the back exit transition.
   @protected
   List<Status> backExitStatuses = [];
 
+  /// Initialize the [AnimationController]s.
   @protected
   void initializeTransitionController() {}
 
@@ -30,20 +38,20 @@ mixin TransitionScreenMixin<T extends StatefulWidget> on State<T> {
 
     initializeTransitionController();
 
-    enterAnimation();
+    _enterAnimation();
 
     context.read<HomeBloc>().stream.listen((state) {
       if (forwardEnterStatuses.contains(state.status)) {
-        enterAnimation();
+        _enterAnimation();
       }
       if (forwardExitStatuses.contains(state.status)) {
-        exitAnimation();
+        _exitAnimation();
       }
       if (backEnterStatuses.contains(state.status)) {
-        popEnterAnimation();
+        _popEnterAnimation();
       }
       if (backExitStatuses.contains(state.status)) {
-        popExitAnimation();
+        _popExitAnimation();
       }
     });
   }
@@ -55,23 +63,19 @@ mixin TransitionScreenMixin<T extends StatefulWidget> on State<T> {
     super.dispose();
   }
 
-  @protected
-  void enterAnimation() {
+  void _enterAnimation() {
     enterTransitionController.forward();
   }
 
-  @protected
-  void exitAnimation() {
+  void _exitAnimation() {
     exitTransitionController.forward();
   }
 
-  @protected
-  void popEnterAnimation() {
+  void _popEnterAnimation() {
     exitTransitionController.reverse();
   }
 
-  @protected
-  void popExitAnimation() {
+  void _popExitAnimation() {
     enterTransitionController.reverse();
   }
 }

lib/home/widgets/welcome_view.dart

@@ -25,6 +25,8 @@ class _WelcomeViewState extends State<WelcomeView>
 
   @override
   void initializeTransitionController() {
+    super.initializeTransitionController();
+
     enterTransitionController = AnimationController(
       vsync: this,
       duration: const Duration(seconds: 1),

test/home/widgets/transition_screen_mixin_test.dart

@@ -110,7 +110,7 @@ void main() {
     });
 
     testWidgets(
-        'calls exitTransitionController forward '
+        'calls exitAnimationController forward '
         'when status is in forwardExitStatuses', (tester) async {
       final streamController = StreamController<HomeState>();
       whenListen(
@@ -180,6 +180,8 @@ void main() {
 
       streamController
           .add(const HomeState(status: Status.askQuestionToThinking));
+
+      await tester.pumpAndSettle();
       verify(() => enterAnimationController.reverse()).called(1);
     });
   });

test/home/widgets/welcome_view_test.dart

@@ -43,6 +43,7 @@ void main() {
         ),
       );
 
+      await tester.pumpAndSettle();
       await tester.tap(find.byType(PrimaryCTA));
 
       verify(() => homeBloc.add(const FromWelcomeToQuestion())).called(1);