chore: add personProfiles support

[marandaneto]

💡 Motivation and Context

Closes #185

When you call identify, alias, or group, if the personProfiles is set to never, the call is NoOp.
If personProfiles is set to always, then $process_person_profile is always true
if personProfiles is set to identified_only, then $process_person_profile is only true is the user is identified.
Otherwise $process_person_profile is always false.

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

[marandaneto]

@robbie-c @raquelmsmith can you double-check the implementation? since the JS bits changed with a few PRs in the last couple le months, just need to be sure that this is the correct behavior.

[robbie-c]

Looks good so far, but needs some logic to change the personless mode for alias, set, etc.

The list in posthog-js is identify, setPersonProperties i.e. set, group, setPersonPropertiesForFlags, setGroupPropertiesForFlags, alias, and createPersonProfile.

IMO you don't need to do it in setPersonPropertiesForFlags and setGroupPropertiesForFlags as these are for local evulation and don't touch person profiles, and we should change posthog-js to match this.

createPersonProfile was added to posthog-js to give people control over when a person profile is created, even if they don't have e.g. a user id or an email address to call identify with. It's less important on mobile than it is for web where you might want to make sure someone has a person profile before they change to a different subdomain.

[robbie-c]

FYI, In posthog-js the default is currently always, though the intention is to change this

[marandaneto]

yes I saw that but the RFC mentions to use the identifiedOnly
https://github.com/PostHog/product-internal/pull/637/files

we should probs update the other stateful SDKs (flutter, iOS, android?) to have the person_profiles config as well, and use the identified_only behavior by default.

So is that OK I guess?

[marandaneto]

Looks good so far, but needs some logic to change the personless mode for alias, set, etc.

The list in posthog-js is identify, setPersonProperties i.e. set, group, setPersonPropertiesForFlags, setGroupPropertiesForFlags, alias, and createPersonProfile.

IMO you don't need to do it in setPersonPropertiesForFlags and setGroupPropertiesForFlags as these are for local evulation and don't touch person profiles, and we should change posthog-js to match this.

createPersonProfile was added to posthog-js to give people control over when a person profile is created, even if they don't have e.g. a user id or an email address to call identify with. It's less important on mobile than it is for web where you might want to make sure someone has a person profile before they change to a different subdomain.

On this SDK we only have identify, group, and alias.
We don't have setPersonProperties, setPersonPropertiesForFlags, setGroupPropertiesForFlags and createPersonProfile (no one ever asked so far).
So I don't follow what has to be changed, mind clarifying?

[robbie-c]

Looks good!

(I'm assuming you'll add tests for sending person properties along with a capture)

[marandaneto]

Looks good!

(I'm assuming you'll add tests for sending person properties along with a capture)

Already did, thanks.