| // 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. |
| |
| // @dart = 2.9 |
| |
| /// @assertion Future doWhile(FutureOr<bool> f()) |
| /// Perform an async operation repeatedly until it returns false. |
| /// . . . |
| /// If a future returned by f completes with an error, iteration ends and the |
| /// future returned by doWhile completes with the same error. |
| /// |
| /// @description Checks that if f returns neither boolean nor Future, it is |
| /// a compile error |
| /// @issue #29202 |
| /// @issue #29257 |
| /// @author a.semenov@unipro.ru |
| |
| import "dart:async"; |
| import "../../../Utils/expect.dart"; |
| |
| const int N = 4; |
| |
| main() { |
| int num = 0; |
| |
| FutureOr<bool> f() { |
| if (num == 2) throw "@"; |
| num++; |
| return new Future.value(num < N); |
| } |
| |
| asyncStart(); |
| Future.doWhile(f).then( |
| (_) { |
| Expect.fail("Returned future should fail with error"); |
| }, |
| onError: (e) { |
| Expect.equals(2, num); |
| asyncEnd(); |
| } |
| ); |
| } |