platform/sandbox/reactivex/test/streams/merge_test.dart
2024-11-12 01:00:05 -07:00

92 lines
2.4 KiB
Dart

import 'dart:async';
import 'package:angel3_reactivex/angel3_reactivex.dart';
import 'package:test/test.dart';
List<Stream<int>> _getStreams() {
var a = Stream.periodic(const Duration(milliseconds: 1), (count) => count)
.take(3),
b = Stream.fromIterable(const [1, 2, 3, 4]);
return [a, b];
}
void main() {
test('Rx.merge', () async {
final stream = Rx.merge(_getStreams());
await expectLater(stream, emitsInOrder(const <int>[1, 2, 3, 4, 0, 1, 2]));
});
test('Rx.merge.iterate.once', () async {
var iterationCount = 0;
final stream = Rx.merge<int>(() sync* {
++iterationCount;
yield Stream.value(1);
yield Stream.value(2);
yield Stream.value(3);
}());
await expectLater(
stream,
emitsInOrder(<dynamic>[
1,
2,
3,
emitsDone,
]),
);
expect(iterationCount, 1);
});
test('Rx.merge.single.subscription', () async {
final stream = Rx.merge(_getStreams());
stream.listen(null);
await expectLater(() => stream.listen(null), throwsA(isStateError));
});
test('Rx.merge.asBroadcastStream', () async {
final stream = Rx.merge(_getStreams()).asBroadcastStream();
// listen twice on same stream
stream.listen(null);
stream.listen(null);
// code should reach here
await expectLater(stream.isBroadcast, isTrue);
});
test('Rx.merge.error.shouldThrowA', () async {
final streamWithError =
Rx.merge(_getStreams()..add(Stream<int>.error(Exception())));
streamWithError.listen(null,
onError: expectAsync2((Exception e, StackTrace s) {
expect(e, isException);
}));
});
test('Rx.merge.pause.resume', () async {
final first = Stream.periodic(const Duration(milliseconds: 10),
(index) => const [1, 2, 3, 4][index]),
second = Stream.periodic(const Duration(milliseconds: 10),
(index) => const [5, 6, 7, 8][index]),
last = Stream.periodic(const Duration(milliseconds: 10),
(index) => const [9, 10, 11, 12][index]);
late StreamSubscription<num> subscription;
// ignore: deprecated_member_use
subscription = Rx.merge([first, second, last]).listen(expectAsync1((value) {
expect(value, 1);
subscription.cancel();
}, count: 1));
subscription.pause(Future<void>.delayed(const Duration(milliseconds: 80)));
});
test('Rx.merge.empty', () {
expect(Rx.merge<int>(const []), emitsDone);
});
}