How to check if an email address is already in use in Firebase on iOS?

Question

I'm using the Firebase Authentication for my iOS App. Now I want to check that the entered email address is available or not. I have found that I have to use createUserWithEmailAndPassword for this. But the issue is I don't want to pass Password. I only want to check using Email. How can I do this?

Answer 1

The following is the structure of the Firebase function you might be looking for (Swift 4):

Auth.auth().fetchProviders(forEmail: emailAddress, completion: {
        (providers, error) in

        if let error = error {
            print(error.localizedDescription)
        } else if let providers = providers {
            print(providers)
        }
    })

If the email address is already registered to a user, you will get a list of the providers that the email address is used for. Otherwise, the list of providers will be empty, and thus the email address is not registered.