LanguageFeatures/Patterns/pattern_assignment_A02_t02.dart

// Copyright (c) 2024, 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 A pattern on the left side of an assignment expression is used to
/// destructure the assigned value. We extend expression:
///
/// expression        ::= patternAssignment
///                     | // Existing productions...
///
/// patternAssignment ::= outerPattern '=' expression
///
/// This syntax allows chaining pattern assignments and mixing them with other
/// assignments, but does not allow patterns to the left of a compound
/// assignment operator.
///
/// @description Check that pattern assignments may be chained. Test
/// parenthesized pattern
/// @author sgrekhov22@gmail.com
/// @issue 55232

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

void main() {
  int v1;
  int v2;
  (v2) = (v1) = 0;
  Expect.equals(0, v1);
  Expect.equals(0, v2);

  (v2) = v1 = 1;
  Expect.equals(1, v1);
  Expect.equals(1, v2);

  v2 = (v1) = 2;
  Expect.equals(2, v1);
  Expect.equals(2, v2);

  (v2) = ((v1)) = (3);
  Expect.equals(3, v1);
  Expect.equals(3, v2);
}