// 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 the null check operator (!) on an
/// expression of type T if T is strictly non-nullable
///
/// @description It is a warning to use the null check operator (!) on an
/// expression of type T if T is strictly non-nullable. Test if (t is Object) {…}
/// @author sgrekhov@unipro.ru
/// @issue 39598
/// @issue 39867


class A {}

test(var a) {
  if (a is Object) {
    a!;
//  ^
// [cfe] Operand of null-aware operation '!' has type 'Object' which excludes null.
//   ^
// [analyzer] STATIC_WARNING.UNNECESSARY_NON_NULL_ASSERTION
  }
}

main() {
  A? a = new A();
  test(a);
}