public static Task <TMessage> Expect <TMessage>(this MessagePipeline <TMessage> pipeline, Predicate <TMessage> filter, CancellationToken cancellationToken = default)
{
var tcs = new TaskCompletionSource <TMessage>();
pipeline.Subscribe(message =>
{
if (filter(message))
{
tcs.TrySetResult(message);
return(new ValueTask <bool>(false));
}
// stay subscribed until we receive the message
return(new ValueTask <bool>(true));
});
// cancel the TCS if the cancellation token expires
cancellationToken.Register(() =>
{
tcs.TrySetCanceled();
}, false);
return(tcs.Task);
}
public static Task <TMessage> Expect <TMessage>(this MessagePipeline <TMessage> pipeline, Predicate <TMessage> filter, TimeSpan timeSpan) => Expect(pipeline, filter, new CancellationTokenSource(timeSpan).Token);
