[Session] Root

[estrattonbailey]

The core issue being solved here is a race condition between the update of currentAccount and the __globalAgent. #3333 set us up so that changing accounts gives us a fresh query cache, which was the impetus behind __globalAgent in the first place (stale closures).

This PR builds on that by deriving currentAccount from the currently active BskyAgent, removing the need to manage updates to two objects (currentAccount and __globalAgent) that have the same lifetime.

In the process, I also split out state handling into separate useState calls to help avoid loops and isolate updates.

• derive currentAccount from BskyAgent.session 4482cbf1436113e1a34c4903bb26635417d1a8cd
• replace mutation of this global state with a call to refresh the session and re-derive ff36564c9b9fc5776de5936e991f33487c4ceafe
• replace usages of previous mutation of global state 80b562cfacf703d2807e9c81f67e187ad43c6017
• refactored persistSession handler for more clarity 634995db38a2f7a3d6b4871b66cafb8480d86877

With this PR, we should now reference the active BskyAgent via { agent } = useSession() and drop the __globalAgent.

Review state/session.ts without whitespace.

[github-actions]

Old size	New size	Diff
6.34 MB	6.34 MB	-1.94 KB (-0.03%)

[estrattonbailey]

So I think this was actually a Bad Thing™. We treat currentAccount as a read-only representation of server state, but in this case we also mutated it and used it to dictate UI state.

I've replaced it with a call to refresh the session and derive currentAccount from that data.

[estrattonbailey]

@gaearon special note of this

[gaearon]

Should we do a pass to use a hook first? And then replace the implementation.

[gaearon]

This assumes that once agent gets into state, its .session and nested fields (e.g. .session.refreshJwt) never changes. Can we make that assumption?

[gaearon]

Alternatively, can rename those to nextAgent.

[estrattonbailey]

Yeah good shout. Those fields are managed internally by BskyAgent. Example: when accessJwt expires, the agent automatically calls refreshSession which updates the session internally. Calls to the currentAgent in client code then automatically use the updated session.

This made me realize how important it is to ensure that fresh tokens get synced across tabs though, gonna triple check that...

[gaearon]

If agent is something that can be mutated on its own, it isn't right to use it as a useMemo input. Since nothing will trigger re-evaluation when these fields change. Let's sync up tomorrow to chat more about this?

[estrattonbailey]

setAgent is called when switching accounts, so each account always has its own agent, and currentAccount can be derived from it. What I'm explaining above isn't something we need to handle directly in this case.

[github-actions]

Old size	New size	Diff
6.36 MB	6.36 MB	-549 B (-0.01%)

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[gaearon]

chatted out of band about this, seems like a promising direction with a few things to fix

[estrattonbailey]

Superseded by #3541 and stack