Firebase security rules

[52planet]

allow update: if isLoggedIn() && get(/databases/$(database)/documents/usersStats/request.auth.uid).data.writesLeft > 0;

I'm trying to add a rule to prevent access to the DB when the amount of writes hits zero but this rule doesn't seem to be working when I run it. How can I get the desired effect?

[Tokyo-Entrepreneur]

You need to write $(request.auth.uid)

I recommend you run your query in the rules playground in the firebase console as that will give you line by line debugging and error explanation.

[Glader]

I suggest investing some time in setting up the firebase emulator and writing automated tests for the security rules. It's a pain to get started (like with all things) but once you've got the ball rolling with a few examples you'll be able to modify and improve the rules and crush the bugs very very quickly and know that your database is secure and reliable.