Testing scheduled messages (actually testing the *when* not the *what*)

[John Thornborrow]

Hi,

We have a need to test the scheduling of messages as they vary depending on shift patterns, day of week, etc and so we have some scenarios like:

Given a ticket was created at 2016-08-30 11:50Z

When the clock strikes 2016-08-31 11:50Z

Then an OpenTicketReminder is published 

Yes, we have unit tests around the module responsible for determining dates but we also want to provide demonstrable tests for our stakeholders/users/etc. thus the high level scenario above.

Naturally we aren't time lords and so I'm looking for a way to control the scheduler to release messages when the test tells it to, instead of waiting for the schedule to naturally expire (and to also use arbitrary dates instead of "now"). I've started to look at creating a test Consumer<ScheduleMessage> for myself, but wondered if a way to do this has already been discovered/solved by anyone? 

Many thanks,

John