Reset global state between unit test runs.
Workaround for #1695 (closed) (This diff resets the state instead of completely removing state)
Completely removing the global state would be much harder, and this diff is enough to get meaningful errors when an Hypothesis-powered test crashes.
It uses the _pre_setup
hook used by [[ https://hypothesis.readthedocs.io/en/latest/django.html | hypothesis[django]
]] to reset Django's database (which is a global state too)
Migrated from D1443 (view on Phabricator)