| // Copyright (c) 2017, 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. |
| |
| import 'dart:async'; |
| |
| /// Returns a [Future] that completes after the [event loop][] has run the given |
| /// number of [times] (20 by default). |
| /// |
| /// [event loop]: https://webdev.dartlang.org/articles/performance/event-loop#darts-event-loop-and-queues |
| /// |
| /// Awaiting this approximates waiting until all asynchronous work (other than |
| /// work that's waiting for external resources) completes. |
| Future pumpEventQueue({int times}) { |
| times ??= 20; |
| if (times == 0) return new Future.value(); |
| // Use [new Future] future to allow microtask events to finish. The [new |
| // Future.value] constructor uses scheduleMicrotask itself and would therefore |
| // not wait for microtask callbacks that are scheduled after invoking this |
| // method. |
| return new Future(() => pumpEventQueue(times: times - 1)); |
| } |
