User lastSignedIn and signedIn info sometimes written in wrong location

[will-hou]

The attendance app crashed today (after many sign-ins and proper functioning in the past few weeks), and I found lastSignedIn and signedIn as entries under /users, which is not supposed to happen.

This bug will break the application until the entry is deleted manually in the real-time database. Haven't gotten to investigate what's causing it but something in the code after moving to the new DB probably wasn't set up correctly.

Will wait until after the build season to look into this further because it happens so rarely and is relatively easy to fix.

[andrewda]

Sounds like someone somehow entered a username that got evaluated to undefined or null or an empty string. Then it would try to put the entry in /users//lastSignedIn, which firebase would automatically simplify to /users/lastSignedIn. You can probably at a check somewhere (be it in firebase rules or in this code) to ensure the user isn't falsey.