/*
 * 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 a warning to use a null aware operator (?., ?.., ??,
 * ??=, or ...?) on a strictly non-nullable receiver. Test type aliases
 * @author sgrekhov@unipro.ru
 * @issue 39598
 */
// SharedOptions=--enable-experiment=non-nullable,nonfunction-type-aliases
// Requirements=nnbd-strong
class A {
  test() {}
}

class C extends A {}

typedef AAlias = A;
typedef CAlias = C;

main() {
  AAlias a = A();
  CAlias c = C();
  a?.test();                                //# 01: static type warning
  a?..test();                               //# 02: static type warning
  a ?? c;                                   //# 03: static type warning
  a ??= c;                                  //# 04: static type warning
  List<CAlias?> clist = [C(), C(), null];   //# 05: static type warning
  List<A> alist = [A(), C(), ...? clist];   //# 06: static type warning
}