LanguageFeatures/Patterns/pattern_assignment_A02_t07.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 it is a run-time error if chained patterns  don't
/// match
/// @author sgrekhov22@gmail.com

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

void main() {
  const one = "1";
  int y = 0;
  Expect.throws(() {
    var z = {"1": y} = {"2": y} = {one: y} = {"1": 2};
  });
  Expect.equals(2, y);
}