Calling reset() causes feature flags lost

[ugurcany]

Version

5.4.1

Steps to Reproduce

1. Call await Posthog().reset() after user logs out on frontend
2. All await Posthog().isFeatureEnabled("feature-key") calls return false afterwards.

Expected Result

Resetting after user logout should still keep the prefetched feature flags.

Actual Result

Preloaded feature flags are lost. However, if I call await Posthog().reloadFeatureFlags() after reset, they are working fine. Not sure if this should be required though.

[marandaneto]

@ioannisj i think reset should reload flags automatically, can you check if we do this on android/ios?

[ioannisj]

@marandaneto Yeah that's the behavior on iOS and Android.

@ugurcany is "feature-key" rolled out to 100% of users and should evaluate to true regardless of anonymous/logged-in in this case?

In case of a reset, we remove local storage, so the flags will evaluate to "false" until they are reloaded async from remote. I believe the missing link here is this PR here actually?

[ugurcany]

@ioannisj yes, it's fully rolled out and auth state is not relevant.

Why do you clear local storage when reset? Shouldnt it only clear user props and nothing else?

[ioannisj]

@ugurcany I believe the rationale behind this is that feature flag values may have evaluated specifically for a distinct id. So on reset() those need to be cleared and re-evaluated for an anonymous user

[marandaneto]

@ugurcany I believe the rationale behind this is that feature flag values may have evaluated specifically for a distinct id. So on reset() those need to be cleared and re-evaluated for an anonymous user

yes, exactly that.

[ugurcany]

@ioannisj @marandaneto still what I need to do is not clear to me. should we call await Posthog().reloadFeatureFlags() after reset?

[ioannisj]

@ugurcany I believe an additional Posthog().reloadFeatureFlags() is not needed since it's already called by iOS and Android SDKs on reset(). I think what you are seeing is probably a side effect of checking flags with a short delay after reset() is called, which gives the net call time to complete (can you verify?).

In the meantime I'll try to get this PR merged soon, where you can use onFeatureFlags callback to re-check flags

[ugurcany]

@ioannisj it doesn't seem like due to checking flags right after reset. they are completely lost until I call "reload flags".

a callback wouldn't help me in my usecase as well.

btw, my platform is Flutter web. not android or ios.

[ioannisj]

btw, my platform is Flutter web. not android or ios.

I see that js lib is also reloading flags on reset(), so behavior should be the same. You should be seeing correct flags values after a short delay when calling reset(). @marandaneto any ideas

[marandaneto]

@ioannisj Nope, pls enable debug mode, check console logs, ask for a repro, etc.
Knowing which org, and flag helps as well to check the flag endpoints via postman as well.
Also SDK version.