| // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'dart:async'; |
| |
| import 'package:async_helper/async_minitest.dart'; |
| |
| main() { |
| test("stream iterator basic", () async { |
| var stream = createStream(); |
| StreamIterator iterator = new StreamIterator(stream); |
| expect(iterator.current, isNull); |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, 42); |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, 37); |
| expect(await iterator.moveNext(), isFalse); |
| expect(iterator.current, isNull); |
| expect(await iterator.moveNext(), isFalse); |
| }); |
| |
| test("stream iterator prefilled", () async { |
| Stream stream = createStream(); |
| StreamIterator iterator = new StreamIterator(stream); |
| await new Future.delayed(Duration.zero); |
| expect(iterator.current, isNull); |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, 42); |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, 37); |
| expect(await iterator.moveNext(), isFalse); |
| expect(iterator.current, isNull); |
| expect(await iterator.moveNext(), isFalse); |
| }); |
| |
| test("stream iterator error", () async { |
| Stream stream = createErrorStream(); |
| StreamIterator iterator = new StreamIterator(stream); |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, 42); |
| var hasNext = iterator.moveNext(); |
| expect(hasNext, throwsA("BAD")); // This is an async expectation, |
| await hasNext.catchError((_) {}); // so we have to wait for the future too. |
| expect(iterator.current, isNull); |
| expect(await iterator.moveNext(), isFalse); |
| expect(iterator.current, isNull); |
| }); |
| |
| test("stream iterator current/moveNext during move", () async { |
| Stream stream = createStream(); |
| StreamIterator iterator = new StreamIterator(stream); |
| var hasNext = iterator.moveNext(); |
| expect(iterator.moveNext, throwsStateError); |
| expect(await hasNext, isTrue); |
| expect(iterator.current, 42); |
| iterator.cancel(); |
| }); |
| |
| test("stream iterator error during cancel", () async { |
| Stream stream = createCancelErrorStream(); |
| StreamIterator iterator = new StreamIterator(stream); |
| for (int i = 0; i < 10; i++) { |
| expect(await iterator.moveNext(), isTrue); |
| expect(iterator.current, i); |
| } |
| var hasNext = iterator.moveNext(); // active moveNext will be completed. |
| var cancel = iterator.cancel(); |
| expect(cancel, throwsA("BAD")); |
| expect(await hasNext, isFalse); |
| expect(await iterator.moveNext(), isFalse); |
| }); |
| |
| test("regression 43799 (1)", () async { |
| // See: https://github.com/dart-lang/sdk/issues/43799 |
| var badStream = StreamController<int>.broadcast(sync: true); |
| badStream.onListen = () { |
| badStream.add(1); |
| badStream.close(); |
| }; |
| var it = StreamIterator(badStream.stream); |
| expect(await it.moveNext(), false); |
| }); |
| |
| test("regression 43799 (2)", () async { |
| // See: https://github.com/dart-lang/sdk/issues/43799 |
| var badStream = StreamController<int>.broadcast(sync: true); |
| badStream.onListen = () { |
| badStream.addError("bad"); |
| }; |
| var it = StreamIterator(badStream.stream); |
| expect(it.moveNext(), expectAsync(throwsA("bad"))); |
| }); |
| } |
| |
| Stream createStream() async* { |
| yield 42; |
| yield 37; |
| } |
| |
| Stream createErrorStream() async* { |
| yield 42; |
| // Emit an error without stopping the generator. |
| yield* (new Future.error("BAD").asStream()); |
| yield 37; |
| } |
| |
| /// Create a stream that throws when cancelled. |
| Stream createCancelErrorStream() async* { |
| int i = 0; |
| try { |
| while (true) yield i++; |
| } finally { |
| throw "BAD"; |
| } |
| } |