Don't keep checking whether the access token that was just fetched is already expired

[sync-by-unito]

realm/realm-js#3985
Likely what’s happening is that if the device time is more than 30 min in the future, it thinks its access token is expired, so it requests a new one. But that one will also (immediately) appear to be expired too, so it tries again, etc. in an infinite loop. 
To mitigate this, the client could check if the newly minted access token is already expired. If it is, then likely there's an unrecoverable issue.

[nirinchev]

Rather than use the expires_at field as it is, we should probably calculate expiration date from the difference between expires_at and issued_at and add that to the local device time.

[jsflax]

That doesn't sound right unless issued_at corresponds with the "incorrect" device time. Which if that's the case, fine, but I would have expected expires_at to also correspond with the "incorrect" device time.

[nirinchev]

issued_at and expires_at are set by the server and should be "correct". The device should not try and validate tokens and instead trust the server - the expires_at check is just an optimization to proactively refresh the token and not something that we should be overly strict at enforcing. So if the device time is t0 and issued_at == t1 and expires_at == t2, we should assume that we should refresh the token before t0 + (t2 - t1) - 5 minutes or something.

[jsflax]

Fixed by #4943.

[sync-by-unito]

➤ Josman Pérez Expósito commented:

Hello Team, do we have an ETA of when this is going to be fixed? I have seen that the pull request has been accepted and it seems to be pending the merge request. I just want to inform the customer of a potential date.
#4943

Thanks

[nirinchev]

We don't have a timeline yet. We're working on it, but even when it is fixed, it needs to be included in an SDK release. It doesn't seem like an overly urgent issue though, so we won't due out-of-band releases specifically for it. Feel free to tell the customer to watch this issue for updates.

[sync-by-unito]

➤ Josman Pérez Expósito commented:

Great, thanks for the info [~nikola.irinchev]