LanguageFeatures/nnbd/Constant-update-2018/TypeTestOperator_A01_t02.dart

// 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 An expression of the form [e is T] or [e is! T] is accepted as a
/// potentially and compile-time constant expression if [e] is potentially
/// constant or compile-time constant, respectively, and [T] is a compile-time
/// constant type.
/// @description Checks that an expression of the form [e is! T] is accepted if
/// [e] is potentially constant
/// @author iarkh@unipro.ru

// Requirements=nnbd-strong

import "../../../Utils/expect.dart";

class MyClass {
  final String str;
  const MyClass(Object? o) : str = o is! String ? "undefined" : o;
}

main() {
  const MyClass c1 = MyClass("12345");
  Expect.equals("12345", c1.str);

  const MyClass c2 = MyClass(12);
  Expect.equals("undefined", c2.str);

  const MyClass c3 = MyClass(null);
  Expect.equals("undefined", c3.str);
}