Linking anonymous account to phone number

[creativecreatorormaybenot]

This is lacking tests (although I do not know if they are required) and testing from my side. I am currently unable to test it because of this issue, but I figured that I might want to get some feedback already.

This pull request would resolve flutter/flutter#22491.

[kdy1]

This also workarounds flutter/flutter#22304, as I can authenticate user with email first.

[creativecreatorormaybenot]

I can confirm that this is now fully working as expected.
I am not sure what the point of the test functions is, but I added it anyway.

[kdy1]

@creativecreatorormaybenot Does this pr add a feature to send a verification code (without signing in with the phone number flutter/flutter#22304)?

[creativecreatorormaybenot]

@kdy1 This is what verifyPhoneNumber is doing already.

[kf6gpe]

This looks good, except for one teensy formatting nit, if you don't mind. Thanks for the contribution, and thanks especially for including a test with it! If you don't mind updating for the nit and resolving the branch conflict, we'll merge this after. Otherwise, we'll get it picked up eventually.

[collinjackson]

I can take a look at this if conflicts are resolved

[creativecreatorormaybenot]

This is now possible using linkWithCredential and PhoneAuthProvider.getCredential as described here.

[awazgyawali]

Although this is possible using PhoneAuthProvider.getCredential, Android automatically detects SMS code and signs in the user with newer account instead of linking with the current one.

[collinjackson]

You're right @awazgyawali, see flutter/flutter#22304

[awazgyawali]

Thus I have added a PR to fix this, can you look into it? Its a very simple one. #1568