Saving database rules creates a new database on the emulator and applies the rules to it

[REQUIRED] Environment info

firebase-tools: 8.4.2

Platform: Windows

[REQUIRED] Test case

https://github.com/filipesilva/firebase-rtdb-loglevel

[REQUIRED] Steps to reproduce

• git clone https://github.com/filipesilva/firebase-rtdb-loglevel
• cd firebase-rtdb-loglevel
• npm i
• npm run emulators
• open http://localhost:4000/database, see the emulator-test-1 database
• save database.rules.json once
• in the emulator logs in the console, see the following lines:

i  database: Change detected, updating rules for undefined...
+  database: Rules updated.

• open http://localhost:4000/database, see the undefined database

[REQUIRED] Expected behavior

The rules should be applied to emulator-test-1 and no new database should be created.

[REQUIRED] Actual behavior

The rules are applied to a new database named undefined.

You can also change the code in public/index.html if you want to verify if the rules are applied to the correct database, but I was using the same reproduction for both this and https://github.com/firebase/firebase-js-sdk/issues/3211 and since this repro doesn’t actually need to run any database code, I left it as is.

[samtstern]

@karlmarxlopez no this will be included in the next release.

[samtstern]

@filipesilva thanks for the super-clear reproduction! I am working on this now.