You need to go with the mock “Firebase. Auth” method and also set it with the current user option. Although Firebase is not enough challenging because it is an open community but you must know everything about Firebase before proceeding with this software development community. Personally, I have followed several discussions regarding Firebase before its use.
If you are still having issues then special protocols can also assist you for authentication. To sort out this problem you can also follow this Stack Overflow solution. Hopefully, now, you would able to use Firebase with Mockaroo and other databases.