Files
flutter-go/packages/flutter_web/test/foundation/change_notifier_test.dart
2019-08-13 20:38:46 +08:00

355 lines
9.7 KiB
Dart

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Synced. * Contains Web DELTA *
import 'package:flutter_web/foundation.dart';
import 'package:flutter_web_test/flutter_web_test.dart';
class TestNotifier extends ChangeNotifier {
void notify() {
notifyListeners();
}
bool get isListenedTo => hasListeners;
}
class HasListenersTester<T> extends ValueNotifier<T> {
HasListenersTester(T value) : super(value);
bool get testHasListeners => hasListeners;
}
class A {
bool result = false;
void test() {
result = true;
}
}
class B extends A with ChangeNotifier {
@override
void test() {
notifyListeners();
super.test();
}
}
void main() {
testWidgets('ChangeNotifier', (WidgetTester tester) async {
final List<String> log = <String>[];
final VoidCallback listener = () {
log.add('listener');
};
final VoidCallback listener1 = () {
log.add('listener1');
};
final VoidCallback listener2 = () {
log.add('listener2');
};
final VoidCallback badListener = () {
log.add('badListener');
// TODO(flutter_web): Flutter converts throw null to NullThrownError,
// this should be moved to Flutter for web default changed.
throw new NullThrownError();
};
final TestNotifier test = TestNotifier();
test.addListener(listener);
test.addListener(listener);
test.notify();
expect(log, <String>['listener', 'listener']);
log.clear();
test.removeListener(listener);
test.notify();
expect(log, <String>['listener']);
log.clear();
test.removeListener(listener);
test.notify();
expect(log, <String>[]);
log.clear();
test.removeListener(listener);
test.notify();
expect(log, <String>[]);
log.clear();
test.addListener(listener);
test.notify();
expect(log, <String>['listener']);
log.clear();
test.addListener(listener1);
test.notify();
expect(log, <String>['listener', 'listener1']);
log.clear();
test.addListener(listener2);
test.notify();
expect(log, <String>['listener', 'listener1', 'listener2']);
log.clear();
test.removeListener(listener1);
test.notify();
expect(log, <String>['listener', 'listener2']);
log.clear();
test.addListener(listener1);
test.notify();
expect(log, <String>['listener', 'listener2', 'listener1']);
log.clear();
test.addListener(badListener);
test.notify();
expect(log, <String>['listener', 'listener2', 'listener1', 'badListener']);
expect(tester.takeException(), isNullThrownError);
log.clear();
test.addListener(listener1);
test.removeListener(listener);
test.removeListener(listener1);
test.removeListener(listener2);
test.addListener(listener2);
test.notify();
expect(log, <String>['badListener', 'listener1', 'listener2']);
expect(tester.takeException(), isNullThrownError);
log.clear();
});
test('ChangeNotifier with mutating listener', () {
final TestNotifier test = TestNotifier();
final List<String> log = <String>[];
final VoidCallback listener1 = () {
log.add('listener1');
};
final VoidCallback listener3 = () {
log.add('listener3');
};
final VoidCallback listener4 = () {
log.add('listener4');
};
final VoidCallback listener2 = () {
log.add('listener2');
test.removeListener(listener1);
test.removeListener(listener3);
test.addListener(listener4);
};
test.addListener(listener1);
test.addListener(listener2);
test.addListener(listener3);
test.notify();
expect(log, <String>['listener1', 'listener2']);
log.clear();
test.notify();
expect(log, <String>['listener2', 'listener4']);
log.clear();
test.notify();
expect(log, <String>['listener2', 'listener4', 'listener4']);
log.clear();
});
test('Merging change notifiers', () {
final TestNotifier source1 = TestNotifier();
final TestNotifier source2 = TestNotifier();
final TestNotifier source3 = TestNotifier();
final List<String> log = <String>[];
final Listenable merged = Listenable.merge(<Listenable>[source1, source2]);
final VoidCallback listener1 = () {
log.add('listener1');
};
final VoidCallback listener2 = () {
log.add('listener2');
};
merged.addListener(listener1);
source1.notify();
source2.notify();
source3.notify();
expect(log, <String>['listener1', 'listener1']);
log.clear();
merged.removeListener(listener1);
source1.notify();
source2.notify();
source3.notify();
expect(log, isEmpty);
log.clear();
merged.addListener(listener1);
merged.addListener(listener2);
source1.notify();
source2.notify();
source3.notify();
expect(log, <String>['listener1', 'listener2', 'listener1', 'listener2']);
log.clear();
});
test('Merging change notifiers ignores null', () {
final TestNotifier source1 = TestNotifier();
final TestNotifier source2 = TestNotifier();
final List<String> log = <String>[];
final Listenable merged =
Listenable.merge(<Listenable>[null, source1, null, source2, null]);
final VoidCallback listener = () {
log.add('listener');
};
merged.addListener(listener);
source1.notify();
source2.notify();
expect(log, <String>['listener', 'listener']);
log.clear();
});
test('Can remove from merged notifier', () {
final TestNotifier source1 = TestNotifier();
final TestNotifier source2 = TestNotifier();
final List<String> log = <String>[];
final Listenable merged = Listenable.merge(<Listenable>[source1, source2]);
final VoidCallback listener = () {
log.add('listener');
};
merged.addListener(listener);
source1.notify();
source2.notify();
expect(log, <String>['listener', 'listener']);
log.clear();
merged.removeListener(listener);
source1.notify();
source2.notify();
expect(log, isEmpty);
});
test('Cannot use a disposed ChangeNotifier', () {
final TestNotifier source = TestNotifier();
source.dispose();
expect(() {
source.addListener(null);
}, throwsFlutterError);
expect(() {
source.removeListener(null);
}, throwsFlutterError);
expect(() {
source.dispose();
}, throwsFlutterError);
expect(() {
source.notify();
}, throwsFlutterError);
});
test('Value notifier', () {
final ValueNotifier<double> notifier = ValueNotifier<double>(2.0);
final List<double> log = <double>[];
final VoidCallback listener = () {
log.add(notifier.value);
};
notifier.addListener(listener);
notifier.value = 3.0;
expect(log, equals(<double>[3.0]));
log.clear();
notifier.value = 3.0;
expect(log, isEmpty);
});
test('Listenable.merge toString', () {
final TestNotifier source1 = TestNotifier();
final TestNotifier source2 = TestNotifier();
Listenable listenableUnderTest = Listenable.merge(<Listenable>[]);
expect(listenableUnderTest.toString(), 'Listenable.merge([])');
listenableUnderTest = Listenable.merge(<Listenable>[null]);
expect(listenableUnderTest.toString(), 'Listenable.merge([null])');
listenableUnderTest = Listenable.merge(<Listenable>[source1]);
expect(
listenableUnderTest.toString(),
"Listenable.merge([Instance of 'TestNotifier'])",
);
listenableUnderTest = Listenable.merge(<Listenable>[source1, source2]);
expect(
listenableUnderTest.toString(),
"Listenable.merge([Instance of 'TestNotifier', Instance of 'TestNotifier'])",
);
listenableUnderTest = Listenable.merge(<Listenable>[null, source2]);
expect(
listenableUnderTest.toString(),
"Listenable.merge([null, Instance of 'TestNotifier'])",
);
});
test('Listenable.merge does not leak', () {
// Regression test for https://github.com/flutter/flutter/issues/25163.
final TestNotifier source1 = TestNotifier();
final TestNotifier source2 = TestNotifier();
final VoidCallback fakeListener = () {};
final Listenable listenableUnderTest =
Listenable.merge(<Listenable>[source1, source2]);
expect(source1.isListenedTo, isFalse);
expect(source2.isListenedTo, isFalse);
listenableUnderTest.addListener(fakeListener);
expect(source1.isListenedTo, isTrue);
expect(source2.isListenedTo, isTrue);
listenableUnderTest.removeListener(fakeListener);
expect(source1.isListenedTo, isFalse);
expect(source2.isListenedTo, isFalse);
});
test('hasListeners', () {
final HasListenersTester<bool> notifier = HasListenersTester<bool>(true);
expect(notifier.testHasListeners, isFalse);
void test1() {}
void test2() {}
notifier.addListener(test1);
expect(notifier.testHasListeners, isTrue);
notifier.addListener(test1);
expect(notifier.testHasListeners, isTrue);
notifier.removeListener(test1);
expect(notifier.testHasListeners, isTrue);
notifier.removeListener(test1);
expect(notifier.testHasListeners, isFalse);
notifier.addListener(test1);
expect(notifier.testHasListeners, isTrue);
notifier.addListener(test2);
expect(notifier.testHasListeners, isTrue);
notifier.removeListener(test1);
expect(notifier.testHasListeners, isTrue);
notifier.removeListener(test2);
expect(notifier.testHasListeners, isFalse);
});
test('ChangeNotifier as a mixin', () {
// We document that this is a valid way to use this class.
final B b = B();
int notifications = 0;
b.addListener(() {
notifications += 1;
});
expect(b.result, isFalse);
expect(notifications, 0);
b.test();
expect(b.result, isTrue);
expect(notifications, 1);
});
}