| // Copyright (c) 2022, 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 nullAssertPattern ::= primaryPattern '!' |
| /// |
| /// A null-assert pattern is similar to a null-check pattern in that it permits |
| /// non-null values to flow through. But a null-assert throws if the matched |
| /// value is null. It lets you forcibly assert that you know a value shouldn't |
| /// be null, much like the corresponding ! null-assert expression. |
| /// |
| /// @description Check null-assert pattern in a switch expression |
| /// @author sgrekhov22@gmail.com |
| |
| import "../../Utils/expect.dart"; |
| |
| String test(List<String?> list) { |
| return switch (list) { |
| ['name', var name!] => name.substring(0), |
| ['answer', _!] => "answer", |
| _ => "default" |
| }; |
| } |
| |
| main() { |
| Expect.equals("Lily", test(['name', 'Lily'])); |
| Expect.equals("answer", test(['answer', '42'])); |
| } |
