如何检查电子邮件地址是否已在 firebase auth 上注册，就像 firebaseui 一样？

Question

The login sequence of the firebaseui.

The login sequence starts with only an email address.

In case the address has been registered to the firebase, login will continue.

If not added, a new account will be created.

My Question

How can I check an email address that has been registered or not on the firebase auth, as the firebaseui does it? I'm looking for the appropriate API to check the email address if it has been added or not. I've searched on the document firebase. auth. Auth , but I can't find it. I've tried the firebase.auth().signInWithEmailAndPassword(this.email, "") with expect to get the error auth/user-not-found , but I've get auth/wrong-password .

Answer 1

You can use the following method, from the docs:

fetchSignInMethodsForEmail

fetchSignInMethodsForEmail(email: string): Promise<Array<string>>

Gets the list of possible sign in methods for the given email address. This is useful to differentiate methods of sign-in for the same provider, eg. EmailAuthProvider which has 2 methods of sign-in, email/password and email/link.

Error Codes

auth/invalid-email Thrown if the email address is not valid.

Parameters

email: string

Returns Promise<Array<string>>

This will return an error if the email is not registered