LibTest/async/Stream/pipe_A04_t02.test.dart

// Copyright (c) 2011, 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.

/// @assertion Future pipe(StreamConsumer<T> streamConsumer)
///    If the adding of the stream itself fails in some way, then the consumer
/// is expected to be closed, and won't be closed again. In that case
/// the returned future completes with the error from calling addStream.
/// @description Checks that returned future is completed with error from
/// calling addStream. Also check that StreamConsumer.close is not called.
/// @author a.semenov@unipro.ru

library pipe_A04_t02;
import "dart:async";
import "../../../Utils/expect.dart";

class TestStreamConsumer<T> implements StreamConsumer<T> {
  int _closeCallCount = 0;
  StreamController _controller = new StreamController();

  Future addStream(Stream<T> source) {
    return _controller.addStream(source).then(
      (_) {
        _controller.close();
        return new Future.error("addStreamError");
      }
    );
  }

  Future close() {
    _closeCallCount++;
    return new Future.error("closeError");
  }

  Stream get stream => _controller.stream;
  int get closeCallCount => _closeCallCount;
}

void test(CreateStreamFunction create) {
  List values = [];
  TestStreamConsumer<int> c = new TestStreamConsumer<int>();

  Stream<int> s = create([1, 2, 3, 4, 5]);

  c.stream.listen(
    (x) {
      values.add(x);
    },
    onDone:(){
      Expect.listEquals([1, 2, 3, 4, 5], values);
      asyncEnd();
    }
  );

  asyncMultiStart(2);
  s.pipe(c).then(
      (_) {
        Expect.fail("Returned future should complete with error");
      },
      onError:(e) {
        Expect.equals("addStreamError", e);
        Expect.equals(0, c.closeCallCount);
        asyncEnd();
      }
  );
}