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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
void main() {
final MemoryAllocations ma = MemoryAllocations.instance;
setUp(() {
assert(!ma.hasListeners);
});
test('Publishers dispatch events in debug mode', () async {
int eventCount = 0;
void listener(ObjectEvent event) => eventCount++;
ma.addListener(listener);
final int expectedEventCount = await _activateFlutterObjectsAndReturnCountOfEvents();
expect(eventCount, expectedEventCount);
ma.removeListener(listener);
expect(ma.hasListeners, isFalse);
});
testWidgets('State dispatches events in debug mode', (WidgetTester tester) async {
bool stateCreated = false;
bool stateDisposed = false;
void listener(ObjectEvent event) {
if (event is ObjectCreated && event.object is State) {
stateCreated = true;
}
if (event is ObjectDisposed && event.object is State) {
stateDisposed = true;
}
}
ma.addListener(listener);
await tester.pumpWidget(const _TestStatefulWidget());
expect(stateCreated, isTrue);
expect(stateDisposed, isFalse);
await tester.pumpWidget(const SizedBox.shrink());
expect(stateCreated, isTrue);
expect(stateDisposed, isTrue);
ma.removeListener(listener);
expect(ma.hasListeners, isFalse);
});
}
class _TestLeafRenderObjectWidget extends LeafRenderObjectWidget {
@override
RenderObject createRenderObject(BuildContext context) {
return _TestRenderObject();
}
}
class _TestElement extends RootRenderObjectElement{
_TestElement(): super(_TestLeafRenderObjectWidget());
void makeInactive() {
assignOwner(BuildOwner(focusManager: FocusManager()));
mount(null, null);
deactivate();
}
}
class _TestRenderObject extends RenderObject {
@override
void debugAssertDoesMeetConstraints() {}
@override
Rect get paintBounds => throw UnimplementedError();
@override
void performLayout() {}
@override
void performResize() {}
@override
Rect get semanticBounds => throw UnimplementedError();
}
class _TestStatefulWidget extends StatefulWidget {
const _TestStatefulWidget();
@override
State<_TestStatefulWidget> createState() => _TestStatefulWidgetState();
}
class _TestStatefulWidgetState extends State<_TestStatefulWidget> {
@override
Widget build(BuildContext context) {
return Container();
}
}
/// Create and dispose Flutter objects to fire memory allocation events.
Future<int> _activateFlutterObjectsAndReturnCountOfEvents() async {
int count = 0;
final _TestElement element = _TestElement(); count++;
final RenderObject renderObject = _TestRenderObject(); count++;
element.makeInactive(); element.unmount(); count += 3;
renderObject.dispose(); count++;
return count;
}