platform/sandbox/reactivex/test/transformers/switch_map_test.dart

359 lines
10 KiB
Dart

import 'dart:async';
import 'package:angel3_reactivex/angel3_reactivex.dart';
import 'package:test/test.dart';
import '../utils.dart';
Stream<int> _getStream() {
final controller = StreamController<int>();
Timer(const Duration(milliseconds: 10), () => controller.add(1));
Timer(const Duration(milliseconds: 20), () => controller.add(2));
Timer(const Duration(milliseconds: 30), () => controller.add(3));
Timer(const Duration(milliseconds: 40), () {
controller.add(4);
controller.close();
});
return controller.stream;
}
Stream<int> _getOtherStream(int value) {
final controller = StreamController<int>();
Timer(const Duration(milliseconds: 15), () => controller.add(value + 1));
Timer(const Duration(milliseconds: 25), () => controller.add(value + 2));
Timer(const Duration(milliseconds: 35), () => controller.add(value + 3));
Timer(const Duration(milliseconds: 45), () {
controller.add(value + 4);
controller.close();
});
return controller.stream;
}
Stream<int> range() =>
Stream.fromIterable(const [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
void main() {
test('Rx.switchMap', () async {
const expectedOutput = [5, 6, 7, 8];
var count = 0;
_getStream().switchMap(_getOtherStream).listen(expectAsync1((result) {
expect(result, expectedOutput[count++]);
}, count: expectedOutput.length));
});
test('Rx.switchMap.reusable', () async {
final transformer = SwitchMapStreamTransformer<int, int>(_getOtherStream);
const expectedOutput = [5, 6, 7, 8];
var countA = 0, countB = 0;
_getStream().transform(transformer).listen(expectAsync1((result) {
expect(result, expectedOutput[countA++]);
}, count: expectedOutput.length));
_getStream().transform(transformer).listen(expectAsync1((result) {
expect(result, expectedOutput[countB++]);
}, count: expectedOutput.length));
});
test('Rx.switchMap.asBroadcastStream', () async {
final stream = _getStream().asBroadcastStream().switchMap(_getOtherStream);
// listen twice on same stream
stream.listen(null);
stream.listen(null);
// code should reach here
await expectLater(true, true);
});
test('Rx.switchMap.error.shouldThrowA', () async {
final streamWithError =
Stream<int>.error(Exception()).switchMap(_getOtherStream);
streamWithError.listen(null,
onError: expectAsync2((Exception e, StackTrace s) {
expect(e, isException);
}));
});
test('Rx.switchMap.error.shouldThrowB', () async {
final streamWithError = Stream.value(1).switchMap(
(_) => Stream<void>.error(Exception('Catch me if you can!')));
streamWithError.listen(null,
onError: expectAsync2((Exception e, StackTrace s) {
expect(e, isException);
}));
});
test('Rx.switchMap.error.shouldThrowC', () async {
final streamWithError = Stream.value(1).switchMap<void>((_) {
throw Exception('oh noes!');
});
streamWithError.listen(null,
onError: expectAsync2((Exception e, StackTrace s) {
expect(e, isException);
}));
});
test('Rx.switchMap.pause.resume', () async {
late StreamSubscription<int> subscription;
final stream = Stream.value(0).switchMap((_) => Stream.value(1));
subscription = stream.listen(expectAsync1((value) {
expect(value, 1);
subscription.cancel();
}, count: 1));
subscription.pause();
subscription.resume();
});
test('Rx.switchMap stream close after switch', () async {
final controller = StreamController<int>();
final list = controller.stream
.switchMap((it) => Stream.fromIterable([it, it]))
.toList();
controller.add(1);
await Future<void>.delayed(Duration(microseconds: 1));
controller.add(2);
await controller.close();
expect(await list, [1, 1, 2, 2]);
});
test('Rx.switchMap accidental broadcast', () async {
final controller = StreamController<int>();
final stream = controller.stream.switchMap((_) => Stream<int>.empty());
stream.listen(null);
expect(() => stream.listen(null), throwsStateError);
controller.add(1);
});
test('Rx.switchMap closes after the last inner Stream closed - issue/511',
() async {
final outer = StreamController<bool>();
final inner = BehaviorSubject.seeded(false);
final stream = outer.stream.switchMap((_) => inner.stream);
expect(stream, emitsThrough(emitsDone));
outer.add(true);
await Future<void>.delayed(Duration.zero);
await inner.close();
await outer.close();
});
test('Rx.switchMap every subscription triggers a listen on the root Stream',
() async {
var count = 0;
final controller = StreamController<bool>.broadcast();
final root =
OnSubscriptionTriggerableStream(controller.stream, () => count++);
final stream = root.switchMap((event) => Stream.value(event));
stream.listen((event) {});
stream.listen((event) {});
expect(count, 2);
await controller.close();
});
test('Rx.switchMap.nullable', () {
nullableTest<String?>(
(s) => s.switchMap((v) => Stream.value(v)),
);
});
test(
'Rx.switchMap pauses subscription when cancelling inner subscription, then resume',
() async {
var isController1Cancelled = false;
final cancelCompleter1 = Completer<void>.sync();
final controller1 = StreamController<int>()
..add(0)
..add(1)
..onCancel = () async {
await Future<void>.delayed(const Duration(milliseconds: 10));
await cancelCompleter1.future;
isController1Cancelled = true;
};
final controller2 = StreamController<int>()
..add(2)
..add(3)
..onListen = () {
expect(
isController1Cancelled,
true,
reason:
'controller1 should be cancelled before controller2 is listened to',
);
};
final controller = StreamController<StreamController<int>>()
..add(controller1);
final stream = controller.stream.switchMap((c) => c.stream);
var expected = 0;
stream.listen(
expectAsync1(
(v) async {
expect(v, expected++);
if (v == 1) {
// switch to controller2.stream
controller.add(controller2);
await Future<void>.delayed(const Duration(milliseconds: 10));
cancelCompleter1.complete(null);
}
},
count: 4,
),
);
},
);
test('Rx.switchMap forwards errors from the cancel()', () {
var isController1Cancelled = false;
final controller1 = StreamController<int>()
..add(0)
..add(1)
..onCancel = () async {
await Future<void>.delayed(const Duration(milliseconds: 10));
isController1Cancelled = true;
throw Exception('cancel error');
};
final controller2 = StreamController<int>()
..add(2)
..add(3)
..onListen = () {
expect(
isController1Cancelled,
true,
reason:
'controller1 should be cancelled before controller2 is listened to',
);
};
final controller = StreamController<StreamController<int>>()
..add(controller1);
final stream = controller.stream.switchMap((c) => c.stream);
var expected = 0;
stream.listen(
expectAsync1(
(v) async {
expect(v, expected++);
if (v == 1) {
// switch to controller2.stream
controller.add(controller2);
}
},
count: 4,
),
onError: expectAsync1(
(Object error) => expect(error, isException),
count: 1,
),
);
});
test(
'Rx.switchMap pauses the next inner StreamSubscription when pausing while cancelling the previous inner Stream',
() {
var isController1Cancelled = false;
final cancelCompleter1 = Completer<void>.sync();
final controller1 = StreamController<int>()
..add(0)
..add(1)
..onCancel = () async {
await Future<void>.delayed(const Duration(milliseconds: 10));
await cancelCompleter1.future;
isController1Cancelled = true;
};
final controller2 = StreamController<int>()
..add(2)
..add(3)
..onListen = () {
expect(
isController1Cancelled,
true,
reason:
'controller1 should be cancelled before controller2 is listened to',
);
};
final controller = StreamController<StreamController<int>>()
..add(controller1);
final stream = controller.stream.switchMap((c) => c.stream);
var expected = 0;
late StreamSubscription<void> subscription;
subscription = stream.listen(
expectAsync1(
(v) async {
expect(v, expected++);
if (v == 1) {
// switch to controller2.stream
controller.add(controller2);
await Future<void>.delayed(const Duration(milliseconds: 10));
// pauses the subscription while cancelling the controller1
subscription.pause();
// let the cancellation of controller1 complete
cancelCompleter1.complete(null);
// make sure the controller2.stream is added to the controller
await pumpEventQueue();
// controller2.stream should be paused
expect(controller2.isPaused, true);
// resume the subscription to continue the rest of the stream
subscription.resume();
}
},
count: 4,
),
);
},
);
}
class OnSubscriptionTriggerableStream<T> extends Stream<T> {
final Stream<T> inner;
final void Function() onSubscribe;
OnSubscriptionTriggerableStream(this.inner, this.onSubscribe);
@override
bool get isBroadcast => inner.isBroadcast;
@override
StreamSubscription<T> listen(void Function(T event)? onData,
{Function? onError, void Function()? onDone, bool? cancelOnError}) {
onSubscribe();
return inner.listen(onData,
onError: onError, onDone: onDone, cancelOnError: cancelOnError);
}
}