Messaging: `deleteToken` no longer deletes token correctly

[helenaford]

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  this repository, please delete this section.

[REQUIRED] Step 1: Describe your environment

• Xcode version: 12.5
• Firebase SDK version: 8.5.0
• Installation method: CocoaPods (select one)
• Firebase Component: Messaging (Auth, Core, Database, Firestore, Messaging, Storage, etc)

[REQUIRED] Step 2: Describe the problem

FlutterFire: Issue: firebase/flutterfire#6766
RNFB: Issue invertase/react-native-firebase#5570 P/R invertase/react-native-firebase#5571

Steps to reproduce:

Call deleteTokenWithCompletion and inspect the token from tokenWithCompletion and see that it has not changed and is still valid.

From debugging, I can see that when the installations id is refreshed via installations.deleteWithCompletion, the token will always refresh when calling messaging.deleteTokenWithCompletion

This behaviour can be replicated both in FlutterFire and RNFB. My question is what is the correct solution/method to refresh an FCM token?

I've looked through the changelog and the documentation, and it's still not 100% clear to me on how the installations id should be managed in relation to the FCM token.

Any help or guidance on this would be greatly appreciated.

Relevant Code:

By changing the following code, additional requests to deleteTokenWithCompletion will refresh the token:
From:

[[FIRMessaging messaging] deleteTokenWithCompletion:^(NSError *_Nullable error) {
    if (error) {
      [RNFBSharedUtils rejectPromiseWithNSError:reject error:error];
    } else {
      resolve([NSNull null]);
    }
  }];

To:

[[FIRInstallations installations] deleteWithCompletion:^(NSError * _Nullable error) {
    if (error) {
      [RNFBSharedUtils rejectPromiseWithNSError:reject error:error];
    } else {
      resolve([NSNull null]);
    }
  }];

[mikehardy]

More than anything, I am just very eagerly listening here for feedback.

@helenaford to be clear - do you mean that if you never delete installations token, you never get a fresh messaging token? I believe that is clear. However, do you also mean that if you delete installations token once, then you get a fresh messaging token each time you delete messaging token after even if you never delete installations token again ?

I had a hunch that this was - perhaps, maybe - related to old installations prior to the change where Messaging token moved from IID to Installations. However! Testing reports in the react-native-firebase repo indicate this happens with people that have only used react-native-firebase since after that change. Stated differently: This should be reproducible on fresh quickstarts that have never had an installation before.

Separately - I'm curious if using Installations delete vs Messaging delete will have some knock-on side-effect like resetting the in-app-messaging "run only once on this install" triggers. It seems to me that it should have that effect, but is it wanted? Stated differently: are the messaging token and the installations token effectively equal? Should deleting one delete the other? The answer to that might be an opinion vs a technical requirement?

[helenaford]

@mikehardy yes, you only have to delete the installations token once, and then it will be ok again. And, yeah it's not about old installations as I can reliably reproduce this issue by deleting the app, and reinstalling it - it resets the state back to the deleteToken not invalidating the token

I actually think it could be todo with the timing of when the Firebase App instance is initialized as I tried deleting the installations id in AppDelegate.m as the app is launching after:

    if ([FIRApp defaultApp] == nil) {
        [FIRApp configure];
    }
    
    // try to delete the installations token here
    [[FIRInstallations installations] deleteWithCompletion.....

with no luck sometimes. So maybe there's a race condition? But it's very confusing because the initial FCM token that is generated works - messages can be sent to the device via firebase-admin.

In terms of the side-effects of deleting the installations id, I was worried about the same thing. I can confirm it doesn't affect the auth token, but not sure about thein-app-messaging token. I'd guess it would change too. I don't see the harm if it did change, also I think most use-cases of deleting a token on the client are when a user wants to log out or delete their account.

[mikehardy]

I'm tracking an unresolved issue with regard to the exact in-app-messaging "run once per device" scenario I mentioned (it's the source of the scenario I used here) - invertase/react-native-firebase#5535 - but the user never reported findings, so it's just an open question to me.

[charlotteliang]

Can you share with us the debugLog? We should figure out why deleteToken is broken.

[mikehardy]

@chliangGoogle for the avoidance of doubt, can you specify exactly what you mean by "debugLog" and how exactly to obtain it?

If it is what I think you mean, it is (for example) what you would see if you added -FIRDebugEnabled as a build [edited: runtime, see below] argument in the Xcode build scheme, then launched the app on a real device via Xcode and watched the Xcode console?

(if there was some document that clearly explained the process that would actually be helpful - I only know what I typed above from digging through different documents over the last couple years, yet it is something I need to request from people myself - as I support react-native-firebase - fairly frequently, and I have to type it out each time 😅 - plus I may be getting it wrong)

[charlotteliang]

Yes. To enable debug logging set the following application argument: -FIRDebugEnabled (see http://goo.gl/RfcP7r)

[helenaford]

@chliangGoogle thanks I can try and get this information over soon. But, not sure if it will help that much - as it can be repeated in both FlutterFire and RNFB (I don't have a native iOS app I can test with), it seems the issue is within the native iOS SDK itself. If you could also take a look into it internally, it'd be much appreciated.

[charlotteliang]

We are able to reproduce, I'm reaching out to our team for further investigation.