// Copyright (c) 2017, 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 | |
import "package:expect/expect.dart"; | |
class A {} | |
class B extends A {} | |
void main() { | |
B b; | |
A a1 = new B(); | |
A a2 = new A(); | |
b ??= a1; // No error - types compatible | |
b ??= a2; // No error - assignment has no effect | |
b = null; | |
Expect.throwsTypeError(() { | |
b ??= a2; | |
}); | |
} |