LibTest/isolate/ReceivePort/take_A01_t01.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 Stream<T> take(int count)
/// Provides at most the first n values of this stream.
/// Forwards the first n data events of this stream, and all error events,
/// to the returned stream, and ends with a done event.
/// If this stream produces fewer than count values before it's done,
/// so will the returned stream.
/// @description Checks that at most n elements are returned.
/// @author kaigorodov

import "dart:async";
import "../../../Utils/expect.dart";
import "IsolateStream.dart" as IsolateStream;

void check(List data, int count) {
  Stream s = IsolateStream.fromIterable(data);
  Stream t = s.take(count);
  int seen = 0;
  asyncStart();
  t.listen((value) {
    Expect.isTrue(seen < count, "seen=$seen, count=$count");
    Expect.deepEquals(data[seen], value);
    seen++;
  }, onDone: () {
    asyncEnd();
  });
}

main() {
  check([], 0);
  check([], 1);
  check([], 10);
  check([null], 0);
  check([null], 1);
  check([null], 2);
  check([1, 2, 3], 0);
  check([1, 2, 3], 1);
  check([1, 2, 3], 2);
  check([1, 2, 3], 12);
  check([
    [],
    [[]],
    [
      [[]]
    ]
  ], 2);
}