LibTest/async/Completer/completeError_A01_t04.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.

// @dart = 2.9

/// @assertion void completeError(Object exception, [Object stackTrace])
/// Complete future with an error. Completing a future with an error indicates
/// that an exception was thrown while trying to produce a value.
/// If error is a Future, the future itself is used as the error value.
/// @description Checks that if exception is another future f which completes
/// with the error e, completer's future will complete with the error f.
/// @author ilya

import "../../../Utils/expect.dart";

import "dart:async";

main() {
  var completer = new Completer();
  var future = completer.future;

  var e = new Error();

  asyncMultiStart(2);

  var f = new Future.error(e).catchError((x) {
    asyncEnd();
    return x;
  });

  future
    .catchError((e) {
      Expect.identical(f, e);
      asyncEnd();
    });

  completer.completeError(f);
}