Language/Expressions/Assignment/null_aware_assignment_t03.dart

// Copyright (c) 2016, 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 assignment a of the form e1?.v = e2 is equivalent
/// to the evaluation of the expression ((x) => x == null?null : x.v = e2)(e1)
/// unless e1 is a type literal, in which case it is equivalent to e1.v = e2.
/// @description Checks that an assignment a of the form e1?.v = e2 is equivalent
/// to the evaluation of the to e1.v = e2 if e1 is a type literal
/// @author sgrekhov@unipro.ru

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

class C {
  static var v;
}

int count = 0;

int e() {
  count++;
  return 0;
}

main() {
  var x = C?.v = e() + 1;
//         ^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
  Expect.equals(1, C?.v);
//                  ^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
  Expect.equals(1, x);
  Expect.equals(1, count);
}