Fix memory leaks in BottomNavigationBar (#147213)

Author: ValentinVignal

packages/flutter/lib/src/material/bottom_navigation_bar.dart

@@ -802,7 +802,7 @@ class _Label extends StatelessWidget {
 
 class _BottomNavigationBarState extends State<BottomNavigationBar> with TickerProviderStateMixin {
   List<AnimationController> _controllers = <AnimationController>[];
-  late List<CurvedAnimation> _animations;
+  List<CurvedAnimation> _animations = <CurvedAnimation>[];
 
   // A queue of color splashes currently being animated.
   final Queue<_Circle> _circles = Queue<_Circle>();
@@ -820,6 +820,9 @@ class _BottomNavigationBarState extends State<BottomNavigationBar> with TickerPr
     for (final _Circle circle in _circles) {
       circle.dispose();
     }
+    for (final CurvedAnimation animation in _animations) {
+      animation.dispose();
+    }
     _circles.clear();
 
     _controllers = List<AnimationController>.generate(widget.items.length, (int index) {
@@ -1254,6 +1257,7 @@ class _Circle {
 
   void dispose() {
     controller.dispose();
+    animation.dispose();
   }
 }
 

packages/flutter/test/material/bottom_navigation_bar_test.dart

@@ -14,6 +14,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';
 import 'package:vector_math/vector_math_64.dart' show Vector3;
 
 import '../widgets/semantics_tester.dart';
@@ -2187,7 +2188,10 @@ void main() {
     );
   });
 
-  testWidgets('BottomNavigationBar handles items.length changes', (WidgetTester tester) async {
+  testWidgets('BottomNavigationBar handles items.length changes',
+    // TODO(polina-c): remove when fixed https://github.com/flutter/flutter/issues/145600 [leak-tracking-opt-in]
+    experimentalLeakTesting: LeakTesting.settings.withTracked(classes: const <String>['CurvedAnimation']),
+    (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/10322
 
     Widget buildFrame(int itemCount) {
@@ -2322,7 +2326,10 @@ void main() {
       );
     }
     for (int pump = 1; pump < 9; pump++) {
-      testWidgets('pump $pump', (WidgetTester tester) async {
+      testWidgets('pump $pump',
+        // TODO(polina-c): remove when fixed https://github.com/flutter/flutter/issues/145600 [leak-tracking-opt-in]
+        experimentalLeakTesting: LeakTesting.settings.withTracked(classes: const <String>['CurvedAnimation']).withCreationStackTrace(),
+        (WidgetTester tester) async {
         await tester.pumpWidget(runTest());
         await tester.tap(find.text('Green'));