LanguageFeatures/nnbd/static_errors_A06_t26.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<FutureOr<A>> where A is some class
 * @author sgrekhov@unipro.ru
 * @issue 40940
 */

import "dart:async";

class A {}
class X {}

mixin M on X {
  FutureOr<FutureOr<A>> f;
//                      ^
// [analyzer] unspecified
// [cfe] unspecified
}

class C extends X with M {
}

main() {
  new C();
}