LanguageFeatures/Spread-collections/ConstSpreads_A07_t03.dart

// Copyright (c) 2019, 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 It also enables const expressions that refer to constant
/// collections defined elsewhere, which is useful:
///
///   const list = [2, 3];
///   const another = [1, ...list, 4]; // [1, 2, 3, 4].
///
/// @description: Checks that spread element in the map can refer to constant
/// collections defined elsewhere
/// @author iarkh@unipro.ru

import "../../Utils/expect.dart";

const Map map = {2: 20, 3: 30};
const Map? map1 = null;

main() {
  const res1 = {1: 10, ...map, 4: 40};
  Expect.mapEquals({1: 10, 2: 20, 3: 30, 4: 40}, res1);

  const res2 = {1: 10, ...?map, 4: 40};
//                     ^^^^
// [analyzer] STATIC_WARNING.INVALID_NULL_AWARE_OPERATOR
  Expect.mapEquals({1: 10, 2: 20, 3: 30, 4: 40}, res2);

  const res3 = {1: 10, ...?map1, 4: 40};
  Expect.mapEquals({1: 10, 4: 40}, res3);
}