How to enable Firebase Analytics Debugview on Testflight

Question

I am unable to view analytics debug view after I install the app through TestFlight into my test phone.

I have passed in argument -FIRDebugEnabled, and have tried -FIRAnalyticsDebugEnabled but no luck.

-FIRDebugEnabled -FIRAnalyticsDebugEnabled

If I directly installed the app into my test phone through Xcode, the debug view will be available. But if it's installed through TestFlight, the debug view cannot be seen.

Answer 1

Add following code at the first line of application:didFinishLaunchingWithOptions: method of AppDelegate file

CommandLine.arguments.append(contentsOf: ["-FIRDebugEnabled", "-FIRAnalyticsDebugEnabled"])

Answer 2

This can be done by injecting special flags into Firebase's local storages. -FIRDebugEnabled command line argument is being checked by both: FirebaseCore and FirebaseAnalytics frameworks. While the former is saving the flag into shared UserDefaults, the latter is using APMUserDefaults private class, which can be accessed in runtime:

if let APMUserDefaults = NSClassFromString("APMUserDefaults") as AnyObject?,
   let userDefaults = APMUserDefaults.perform(#selector(getter: UserDefaults.standard))?.takeUnretainedValue() {
   _ = userDefaults.perform(#selector(NSMutableDictionary.setObject(_:forKey:)),
                            with: true, 
                            with: "/google/measurement/debug_mode")
}
UserDefaults.standard.set(true, forKey: "/google/firebase/debug_mode")