How to Create a User with Authentication and Write to Firestore Simultaneously?

What are the steps to create a user using Firebase Authentication and simultaneously write their data to Firestore?

const email = '[email protected]';
const password = 'userpassword';
const userData = { name: 'John Doe', age: 30 };

This guide will walk you through the process of creating a user with Firebase Authentication and simultaneously storing their information in Firestore. This is an essential task for any application that requires user management along with associated data storage.

import { getAuth, createUserWithEmailAndPassword } from 'firebase/auth';
import { getFirestore, doc, setDoc } from 'firebase/firestore';

// Initialize Firebase Authentication and Firestore
auth = getAuth();
db = getFirestore();

async function createUserAndWriteToFirestore(email, password, userData) {
    try {
        const userCredential = await createUserWithEmailAndPassword(auth, email, password);
        const user = userCredential.user;

        await setDoc(doc(db, 'users', user.uid), { ...userData });
        console.log('User created and data written to Firestore');
    } catch (error) {
        console.error('Error creating user:', error);
    }
}

Causes

• Firebase Authentication is used for securely creating and managing user accounts.
• Firestore is a NoSQL database that allows you to store user-specific data.

Solutions

• Use the createUserWithEmailAndPassword() method to create a user.
• On successful user creation, use Firestore's set() or add() methods to save user data in the database.
• Use Promises to handle the asynchronous operation of both creating a user and writing to Firestore.

Mistake: Not handling errors correctly during user creation or data writing.

Solution: Always implement try-catch blocks and handle possible errors in the asynchronous functions.

Mistake: Assuming Firestore data structure is conventional.

Solution: Ensure you design your Firestore structure according to your app's data needs, keeping scalability in mind.