Hi Armando,
In the example I related to in my reply here, the approach taken was to store the serialized format of the events as test resources.
So more specifically, we had `.json` files (as we serialized to JSON) containing the structure of the event at a given revision number.
The rest of the file name would resemble the payload type of the event (by default it's class name), appended with the revision number as well.
That way we could introduce an abstract UpcasterTest, which required developers to provide the event name and event revision.
Based on the result of both, the abstract UpcasterTest would expect a file resembling the aforementioned naming scheme and load the file.
The contents of it would thus be the serialized format of the event, exactly what we needed to test the upcaster with.
Hope this clarified some things Armando!
Cheers,
Steven