LanguageFeatures/nnbd/Least-greatest-closure/typedef/typedef_static_t15.dart

/*
 * Copyright (c) 2020, 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 The definitions of least and greatest closure are changed in null
 * safe libraries to substitute [Never] in positions where previously [Null
 * would have been substituted, and [Object?] in positions where previously
 * [Object] or [dynamic] would have been substituted.
 * @description Check that correct type is substituted for [typedef check<X> =
 * void Function()].
 * @note Read more about the least and greatest closure test template:
 * https://github.com/dart-lang/co19/issues/575#issuecomment-613542349
 *
 * @author iarkh@unipro.ru
 */

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

typedef check<X> = void Function();

void main() {
  void f<X>(check<X> Function() g) => g();

  // Verify that we can call the function with the specified arguments.
  f(() => captureTypeArgument()..call());

 // Verify that a couple of wrong argument lists are rejected.
  f(() => captureTypeArgument()..call(throw 1));
  //                                 ^
  // [analyzer] unspecified
  // [cfe] unspecified

  f(() => captureTypeArgument()..call('Hello'));
  //                                 ^
  // [analyzer] unspecified
  // [cfe] unspecified

  f(() => captureTypeArgument()..call(arg: 'Hello'));
  //                                  ^^^
  // [analyzer] unspecified
  // [cfe] unspecified

  // Verify that the return type is `void`: Returned value not usable,
  // not even to access a member of `Object`.
  f(() => captureTypeArgument()..call().toString());
  //                             ^
  // [analyzer] unspecified
  // [cfe] unspecified
}