Add pytest-insta

[Litarnus]

Required for getsentry/relay#4877

[asottile-sentry]

is this for use in sentry? we've been trying to strongly discourage snapshot testing as they tend to lead to flakiness and people blindly accepting new snapshots rather than actually debugging and fixing problems.

we've removed two snapshotting systems from sentry already and would strongly recommend against adding a new one. there's already a snapshotting system in place as well but generally is discouraged from use (the pysnap system)

[Litarnus]

is this for use in sentry?

No this is meant to be used in relay. We have tests that would strongly benefit from snapshot testing, especially PII tests.
I also added a fixture within relay to replace dynamic data to not make it flaky (or rather, make snapshots work in general)

there's already a snapshotting system in place as well but generally is discouraged from use (the pysnap system)

Do you mean the one that uses rust insta under the hood? I didn't see a different one in the list of dependencies.
I looked at it and I think it would be rather complex to make it work in relay, while this one is fairly easy.

[untitaker]

pytest-insta did not exist at the time that pysnap was built into sentry. i think we should adopt pytest-insta and remove pysnap entirely. from what I remember pysnap is mainly used in grouping tests which are not flaky afaik. minidump tests in sentry are sometimes flaky, if we think removing snapshotting would reduce the amount of flakiness there let's just remove it there? maybe the guidance can be relaxed to: no snapshotting outside of unit tests?