fix(firebase_auth_platform_interface): details['code'] null check

[Yokoi-K]

Description

My team detected the following error logs while using this plugin.

_TypeError
type 'Null' is not a subtype of type 'String'

method_channel_firebase_auth.dart in MethodChannelFirebaseAuth.verifyPhoneNumber.<fn> at line 660 within firebase_auth_platform_interface

↓
https://github.com/firebase/flutterfire/blob/master/packages/firebase_auth/firebase_auth_platform_interface/lib/src/method_channel/method_channel_firebase_auth.dart#L660

Apparently, details['code'] is sometimes null, and code is a non-null definition, so we need to do a good null check.

Related Issues

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[Lyokone]

Thanks for this :)

[mariopepe]

First of all thanks a lot @Yokoi-K .
I was having the issue that was addressed with this PR, so I am thankful for it.

My situation was the following:

1. the user was inserting phone number (note: my data, might be wrong, tell me that this is something that happened most of the times with users signing up for the first time ever)
2. the user was receiving the OTP code
3. the user was inserting the correct OTP
4. but was not able to access complete the verification (i.e. I was calling the method signInWithCredential with the correct smsCode and verificationId but the authentication created problems).

Now since this fix (thanks again!) I am not seeing anymore this error, but looking at my crash and analytics data, it still seems that my users have difficulties while performing successful authentication from Android (same as before).

So my question for you is:
did you had the chance to investigate which were the reasons that, in the first place, where generating that FirebaseAuthException for your users? Did you had the chance to verify that the AuthException was raised, in the first place, for good reasons?
My speculation, might be wrong, is that this exception is being thrown for some bug elsewhere in the plugin and now with this PR we only made it so that the the exception does not throw another exception (🤦🏼‍♂️) but we did not find yet the upstream cause.

Many people at the moment are having issues with firebase auth via phone:

• [firebase auth] verify phone number not working on release application flutter #10139
• 🐛 [firebase_auth] App crashes on sms / phone authentication #10012

[Yokoi-K]

@mariopepe

Sorry for the late reply.
I think you are right.

My PR fix is measure NullPointerException.
So I don't know what the essential issue of FirebaseAuthException is.

Thanks.