Run functions on Auth events

Register functions that listen and react to Firebase Auth events.

Blocking functions

run a function before the user is added to Firebase Auth

The function is blocking: We perform validation, and, if applicable, throw an error to deny the registration. Firebase Auth aborts user creation on throw. The Auth client SDK receives such error and can display it to the user"

export const onRegisterBlocking = beforeUserCreated(options, async (event) => {
    const user = event.data // AuthUserRecord === UserRecord
    // user.uid
    // user.email
    if (user?.email?.includes("@hotmail.com")) {
        throw new HttpsError("invalid-argument", "don't use hotmail")
    }
    // create the user in the database first, then return
    await createDefaultDataForUser(user)
    return
})

Non blocking functions

The non blocking functions run after a user has been created (or deleted) by Firebase Auth.

As of writing, there is no v2 version for the non blocking functions.

export const f = auth.user().onCreate(async (user) => {})
export const g = auth.user().onDelete(async (user) => {})

example: add the user to the Firestore database

We read the auth user's uid and create a user document with it:

export const onRegisterNonBlocking = region("europe-west1")
    .auth.user()
    .onCreate(async (user) => {
        const { uid, email } = user
        await db.collection("users").doc(uid).set({ uid, email })
    })

example: delete the user from the Firestore database

export const onDeleteAccount = region("europe-west1")
    .auth.user()
    .onDelete(async function (user) {
        const { uid } = user
        await db.doc("users/" + uid).delete()
    })