InAppMessagingDisplay stops receiving Analytics events when GTM json container is added

[fgulan]

[READ] Step 1: Are you in the right place?

I believe I am :)

[REQUIRED] Step 2: Describe your environment

• Xcode version: 11.1
• Firebase SDK version: 6.12.0
• Firebase Component: Analytics, Core, InAppMessagingDisplay, GoogleTagManager (7.1.2)
• Component version: FirebaseInAppMessaging (0.15.5)

[REQUIRED] Step 3: Describe the problem

InAppMessagingDisplay stops displaying messages triggered by analytics event when Google Tag Manager is used, more correctly when container JSON file is added to project.

From what I debugged, method messageTriggered:parameters: on FIRIAMDisplayCheckOnAnalyticEventsFlow is not invoked on analytics events when mentioned JSON file is included. Not sure what could be the issue but maybe GTM internally swizzle something or doesn't call super implementation, since if I remove JSON container from project that method is invoked and messages are shown.

Steps to reproduce:

I've created example iOS project where you can reproduce the issue: https://github.com/fgulan/fiam-gtm-issue. Google plist and GTM container json are included in project with my test data. Just run the app and you should see the button which triggers analytics event open_fiam which should trigger displaying FIAM banner message with text Test FIAM. But it doesn't since JSON container is added as a reference, just remove it to see the difference.

[christibbs]

@fgulan looking into this. As a temporary workaround you can trigger the message directly via the InAppMessaging singleton.

InAppMessaging.inAppMessaging().triggerEvent("open_fiam")

[christibbs]

I debugged this via @fgulan's sample project (needed to create my own project and replace the GoogleService-Info.plist file) and confirmed that the failure point is messageTriggered:parameters: not getting called. So the bug happens on the analytics side before it reaches the in-app messaging SDK.

[paulb777]

Created internal issue b/145705671

[paulb777]

Fix implemented for next release.

[paulb777]

Fix released with Firebase 6.14.0