runAsync< T> method
Runs a callback
that performs real asynchronous work.
This is intended for callers who need to call asynchronous methods where the methods spawn isolates or OS threads and thus cannot be executed synchronously by calling pump.
If callback
completes successfully, this will return the future
returned by callback
.
If callback
completes with an error, the error will be caught by the
Flutter framework and made available via takeException, and this method
will return a future that completes will null
.
Re-entrant calls to this method are not allowed; callers of this method are required to wait for the returned future to complete before calling this method again. Attempts to do otherwise will result in a TestFailure error being thrown.
The additionalTime
argument is used by the
AutomatedTestWidgetsFlutterBinding implementation to increase the
current timeout. See AutomatedTestWidgetsFlutterBinding.addTime for
details. The value is ignored by the LiveTestWidgetsFlutterBinding.
Implementation
Future<T> runAsync<T>(Future<T> callback(), {
Duration additionalTime = const Duration(milliseconds: 250),
});