LanguageFeatures/nnbd/static_errors_A06_t18.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 It is an error if a mixin declaration or a class declaration with
 * no generative constructors declares an instance variable with a potentially
 * non-nullable type and no initializer expression unless the variable is marked
 * with the late modifier.
 *
 * @description Check that it is an error if a mixin declaration with no
 * generative constructors declares an instance variable with a potentially
 * non-nullable type and no initializer expression. Test FutureOr<F> where
 * F is a function type
 * @author sgrekhov@unipro.ru
 * @issue 40940
 */

import "dart:async";

typedef void Foo();
void foo() {}
class X {}

mixin M on X {
  FutureOr<Function> f1;
//                   ^^
// [analyzer] unspecified
// [cfe] unspecified
  FutureOr<Foo> f2;
//              ^^
// [analyzer] unspecified
// [cfe] unspecified
}

class C extends X with M {
}

main() {
  new C();
}