LibTest/async/Future/catchError_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.

// @dart = 2.9

/// @assertion Future catchError(Function onError, {bool test(Object error)})
///    Handles errors emitted by this Future.
///    This is the asynchronous equivalent of a "catch" block.
///    Returns a new Future that will be completed with either the result of
/// this future or the result of calling the onError callback.
/// @description Checks that [catchError] returns a new Future f.
/// @author kaigorodov

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

void onError(Object asyncError) {}

void check (Future f1) {
  Object f2 = f1.catchError(onError);
  Expect.isTrue(f2 is Future);
  Expect.isFalse(identical(f1, f2));
}

main() {
  check(new Completer().future);
  check(new Future.sync(() => 1));
  check(new Future.sync(() {throw 1;}));
}