| /* |
| * Copyright (c) 2019, 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 a warning to use a null aware operator (?., ?.., ??, ??=, |
| * or ...?) on an expression of type T if T is strictly non-nullable. |
| * |
| * @description Check it is no warning if null aware operators (?., ?.., ??, |
| * ??=, or ...?) are used on a nullable receiver. |
| * @author sgrekhov@unipro.ru |
| */ |
| // SharedOptions=--enable-experiment=non-nullable |
| // Requirements=nnbd-strong |
| class A { |
| test() {} |
| } |
| |
| class C extends A {} |
| |
| main() { |
| A? a = A(); |
| C c = C(); |
| a?.test(); |
| a?..test(); |
| a ?? c; |
| a ??= c; |
| List<C>? clist = [C(), C()]; |
| List<A> alist = [A(), C(), ...? clist]; |
| |
| a = null; |
| a?.test(); |
| a?..test(); |
| a ?? c; |
| a ??= c; |
| clist = null; |
| alist = [A(), C(), ...? clist]; |
| } |