Postgres function should_update_person_props

[yakkomajuri]

Changes

WIP

This is a key step for https://github.com/PostHog/plugin-server/issues/371

This was forked off of #6253.

Putting it out as a WIP in order to get feedback quickly before moving onto plugin server work.

Massive shoutout to @tiina303 for the table you wrote about how this function should behave. Made this so much easier, particularly writing tests.

How did you test this code?

Added tests for every potential case the function would encounter.

[yakkomajuri]

Could realistically get rid of #6253 in favor of this if we're able to merge quickly - maybe even make it one migration only 🤔

[tiina303]

Approving, but do address my comment about equal timestamps function output value before landing.

Could realistically get rid of 6253 in favor of this if we're able to merge quickly

I'm fine with that, see comments there too.

This was forked off

btw you can use --base <the-other-branch-name> which will make it show only the new code here in code review. Not yet fully sure how to merge on master later, but I think it's possible to select a branch or alternatively rebase on master locally first & force push an update.

Added tests for every potential case the function would encounter.

❤️

[yakkomajuri]

@tiina303 well if I set the base as the other branch it will only show what's new but it will be a PR to that branch, not master, which is where I want the changes to go 😆

Great comments though, will address

[hazzadous]

What's the reason for doing this as a psql function btw?

[yakkomajuri]

@hazzadous this will make things so much cleaner and easier to debug. The query for updating properties is already going to be somewhat messy and this helps abstract some of it away + test it individually.

It's not necessary, but much easier to work with/debug/think about conceptually.

[hazzadous]

Ok. I wonder what the process is for updating these types of things e.g. do we have to create a migration each time we want to update and test and deploy, and how experienced/comfortable people will be to make changes to this.

[tiina303]

Awesome 🚢