LibTest/isolate/Isolate/spawn_A02_t02.dart

// Copyright (c) 2011-2016, 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<Isolate> spawn(void entryPoint(message), message,
/// {bool paused: false, bool errorsAreFatal, SendPort onExit, SendPort onError})
///
///    The argument entryPoint specifies the entry point of the spawned isolate.
/// It must be a top-level function or a static method that takes one argument -
/// that is, one-parameter functions that can be compile-time constant function
/// values. It is not allowed to pass the value of function expressions or
/// an instance method extracted from an object.
///
///    The entry-point function is invoked with the initial message. Usually
/// the initial message contains a SendPort so that the spawner and spawnee can
/// communicate with each other.
///  ...
///    Returns a future that will complete with an Isolate instance if
/// the spawning succeeded. It will complete with an error otherwise.
///
/// @description Checks that if entryPoint is null, then returned Future
/// instance completes with error
///
/// @author iefremov
/// @author a.semenov@unipro.ru

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

main() {
  asyncStart();
  Isolate.spawn(null, "hello").then(
    (v) {
      Expect.fail("Isolate.spawn(null, 'hello') is expected to fail");
    },
    onError: (e) {
//      print("Error: $e");
      asyncEnd();
    }
  );
}