Language/Expressions/If_null_Expressions/static_type_t01.dart

/*
 * Copyright (c) 2015, 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 Evaluation of an if-null expression e of the form e1??e2 is
 * equivalent ... The static type of e is least upper bound of the
 * static type of e1 and the static type of e2 .
 *
 * @description Check that static type of expression e1??e2 match with
 * static type (int) in assignment.
 *
 * @static-clean
 * @author a.semenov@unipro.ru
 */

import '../../../Utils/dynamic_check.dart';


main() {
  int x = 1 ?? 2;
  x = 1 ?? 2.0;
  checkTypeError(() { int y = 2.0 ?? 1; return y; });
  x = null ?? 1;
  x = null ?? null;
  x = 1 ?? null;
  x = 1 ?? 'aaa';
  checkTypeError(() { int y = 'aaa' ?? 1; return y; });
  checkTypeError(() { int y = 'aaa' ?? true; return y; });
  return x; // use x, so dart analyzer is happy
}