fix(firebase_auth): TenantId can be reset to null after being set to something else

[Rexios80]

Description

Existing behavior

• Cannot set tenantId to null after setting it to something else

New behavior

• Setting tenantId back to null works as expected

Motivation

• This is how the native SDKs work

I was unsure how to write tests for this. The existing tenantId tests don't look like they actually interact with the platform code. If anyone could point me in the right direction I would be happy to write them.

Related Issues

#7896 (comment)

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[Rexios80]

Welp it looks like this issue goes deeper than just this plugin

In the native Android SDK:

    public void setTenantId(@NonNull String param1) {
        // $FF: Couldn't be decompiled
    }

I don't think that code is open source, so I'm stuck on this. I definitely think you're supposed to be able to set the tenantId back to null. The iOS and web SDKs let you, and the value defaults to null anyways.

[russellwheatley]

Hey @Rexios80, this is worth raising on the firebase-android-sdk I believe. It looks like it probably shouldn't be @nonnull annotated but worth finding out what folks on that repo think 😄.

[Salakar]

@Rexios80 please let me know if you've raised an issue for this and we can mention it to the Android SDK devs

[Rexios80]

@Salakar firebase/firebase-android-sdk#3398