Hitting eventsourcing.exceptions.EventHashError

Hi there, I’m currently playing around with the library and I’m hitting the following run time error when running two commands in a row and then attempting to look up the aggregate root id within app.repository:

python3.7/site-packages/eventsourcing/domain/model/events.py", line 139, in check_hash raise EventHashError() eventsourcing.exceptions.EventHashError

The code is available here https://github.com/AlanFoster/eventsourcing and the error is reproducible with:

pipenv shell
pipenv install
pipenv run python main.py

From what I can tell this might be a bug within the library, but I’m not sure just yet! I’d be keen to know your thoughts 👍

[AlanFoster]

Thank you for looking into this! That’s helped clear up everything for me, thanks very much 👍

[johnbywater]

One more thing to watch out for, something which I feel is slightly deficient: if you use integer values for dict keys, as you do in your program, then you should be aware that they get converted to strings by JSON (at least the JSON module used by the library at the moment, which is the core Python json implementation) so when you look at a domain event object that has been reconstructed from a serialised record, then it can have string dict keys instead of integer dict keys. Then if you use these keys in a mutator to set values on an aggregate, and later try get values with integer keys, the value will appear to be missing. If you want to avoid this, then either make sure you just don’t use integer dict keys in the domain events, or make sure than you defensively convert to integers in the mutator. I’ve got no idea why the json module works this way.