Language/Expressions/Unary_Expressions/variable_negative_t03.dart

// Copyright (c) 2011, 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

/// @assertion The expression !e is equivalent to the expression
/// e ? false : true.
/// @description Checks that, just like with conditional expressions, it is
/// a dynamic type error in checked mode when e is not a boolean and it is
/// subjected to a boolean conversion in scripting mode.
/// @author rodionov

import '../../../Utils/expect.dart';

main() {
  var v = null;
  Expect.throws(() {Expect.isTrue(!v);});
  v = "true, honestly";
  Expect.throws(() {Expect.isTrue(!v);});
  v = () {};
  Expect.throws(() {Expect.isTrue(!v);});
}