FirebaseApp.configure() has an error use of unresolved identifier 'FirebaseApp'

Question

So every time in my pod file I decide to add something like pod 'Firebase/Storage’ with pod 'Firebase/Core’, in my app delicate FirebaseApp.configure() has an error use of unresolved identifier 'FirebaseApp' my pod file is

https://docs.google.com/document/d/1U7s5StRuNrI_2WtpHSvHhwhA1TMCsQ255dnjDAEhhcE/edit?usp=sharing

Answer 1

I solved this problem by using FirebaseCore instead of Firebase library:

import FirebaseCore

Answer 2

Your appdelegate class should look like this:

import UIKit
import Firebase

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        FIRApp.configure()
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }
}

I am assuming you are using xcode 8 and swift 3.

Answer 3

In my case was because I was using an older version of Firebase (3.11.1)

pod repo update
pod update

After update my repo and my local specs repositories with Firebase (4.2.0) FirebaseApp was resolved by Xcode!

Answer 4

Run pod update to at least Firebase 6.31.1.

Firebase made a change in 6.28.0 that exposed an Xcode build race condition. The change was reverted in 6.31.1. Details at https://github.com/firebase/firebase-ios-sdk/issues/6341

Answer 5

Try pod 'Firebase' instead of pod 'Firebase/Core'

And check if Firebase 4.x was installed after 'pod install'

Answer 6

use "import FirebaseCore" , instead of "import Firebase"

Answer 7

This will resolve this

 sudo gem install cocoapods 
 pod update

Answer 8

The solution by morganchen12 at this GitHub comment resolved the same issue for me. I needed to modify the Podfile for the unit tests (OP already completed), and then add Firebase to the Header Search paths.

For preservation, the comment is:

The issue is caused by duplicate FIRApp class definitions in the test runtime.

Your Podfile should look like this:

target "FirebaseDemo" do
  install_pods

  target "FirebaseDemoTests" do
    inherit! :search_paths
  end
end

In order to avoid the missing required module Firebase error, add "${PODS_ROOT}/Firebase/Core/Sources" to the end of your test target's Header Search Paths in Xcode.

Answer 9

My pod file has Firebase/Core and Firebase/Auth.

updating the pod didn't solve it for me and I also tried pod 'Firebase'. It was simply this mistake