[🐛] Bug Report Title - FirebaseApp.configure() not working in React Native 0.79.1 AppDelegate.swift using New Architecture

[Spero-Sourabh]

I'm trying to configure Firebase in a React Native 0.79.1 app using the new architecture. The AppDelegate.swift file format has changed in RN 0.79+, and FirebaseApp.configure() does not seem to initialize Firebase properly when added to this file.

Environment:

React Native version: 0.79.1

Firebase module: @react-native-firebase/app (or whatever module you're using)

macOS version:15.2

Xcode version: 16.0

Cocoapods version: 1.16.2

iOS deployment target: ios 18

Steps to reproduce:

Install Firebase via CocoaPods.

Add FirebaseApp.configure() to AppDelegate.swift.

Run the app using yarn ios.

Expected behavior: Firebase should initialize successfully without errors.

Actual behavior: Firebase is not initialized, or no logs confirm that FirebaseApp.configure() ran successfully. Sometimes other Firebase modules throw "not configured" errors.

AppDelegate.swift Code:

import UIKit
import React
import React_RCTAppDelegate
import ReactAppDependencyProvider
import FirebaseCore

@main
class AppDelegate: UIResponder, UIApplicationDelegate {
  var window: UIWindow?

  var reactNativeDelegate: ReactNativeDelegate?
  var reactNativeFactory: RCTReactNativeFactory?

  func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
  ) -> Bool {

    FirebaseApp.configure()

    let delegate = ReactNativeDelegate()
    let factory = RCTReactNativeFactory(delegate: delegate)
    delegate.dependencyProvider = RCTAppDependencyProvider()

    reactNativeDelegate = delegate
    reactNativeFactory = factory

    window = UIWindow(frame: UIScreen.main.bounds)

    factory.startReactNative(
      withModuleName: "skyzone",
      in: window,
      launchOptions: launchOptions
    )

    return true
  }
}

Additional context: I've verified the GoogleService-Info.plist file is added to the correct target. I’ve also confirmed that Firebase is installed via pod install. No compile-time errors are present, but Firebase is not functioning as expected.

[mikehardy]

We see people complaining of this or similar build issues from time to time and it always seems to have a different cause. There are unfortunately a million ways it can go wrong. We are unable to help everyone with every single failure mode, as the support load would be impossible to bear.

What I've got instead is a complete, 100% scripted example of a react-native-firebase integration with the stock react-native template that has comments and starts from scratch (npx @react-native-community/cli init ...) and integrates everything in a scripted way (so you can see exactly what it does, and what the result looks like) and then runs debug and release builds.

It works every time

https://github.com/mikehardy/rnfbdemo/blob/main/make-demo.sh

Read it. Run it. Compare the output with your project. Somewhere in the difference is why your build is failing