LibTest/isolate/ReceivePort/first_A02_t02.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 final Future<T> first
/// If this stream is empty (a done event occurs before the first data event),
/// the resulting future completes with a StateError.
/// Except for the type of the error, this method is equivalent to
/// this.elementAt(0).
/// @description Checks that for non-empty stream, this.first is equivalent to this.elementAt(0).
/// @author kaigorodov

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

const VAL = 123;

void check(Stream s) {
  asyncStart();
  s.elementAt(0).then((value) {
    Expect.equals(VAL, value);
    asyncEnd();
  });
}

main() {
  check(IsolateStream.fromIterable([VAL, 2, 3]));
  check(
      IsolateStream.fromIterable(new Iterable.generate(1, (int index) => VAL)));
}