NextAuth.js (Auth.js) setup in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the NextAuth function from the correct package.

NextJS

import NextAuth from '[1]';

Drag options to blanks, or click blank then click option'

Anext-auth

Breact-auth

Cnext-auth-client

Dauth-next

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect package names like 'react-auth' or 'auth-next'.

Forgetting to install the 'next-auth' package before importing.

The NextAuth function is imported from the next-auth package, which is the official library for authentication in Next.js.

2fill in blank

medium

Complete the code to export the NextAuth handler as the default export.

NextJS

export default NextAuth([1]);

Drag options to blanks, or click blank then click option'

Acallbacks

Bconfig

Cproviders

Doptions

Attempts:

3 left

💡 Hint

Common Mistakes

Passing only 'providers' without wrapping in a config object.

Using incorrect property names.

The NextAuth function expects a configuration object, often named config, which includes providers and other settings.

3fill in blank

hard

Fix the error in the providers array by completing the import for GitHub.

NextJS

import GitHub from '[1]';

Drag options to blanks, or click blank then click option'

Anext-auth/providers/github

Bnext-auth/github-provider

Cnext-auth/providers/GitHub

Dnext-auth/provider/github

Attempts:

3 left

💡 Hint

Common Mistakes

Capitalizing 'GitHub' in the import path.

Using incorrect folder names like 'provider' instead of 'providers'.

The correct import path for GitHub is next-auth/providers/github with lowercase 'github'.

4fill in blank

hard

Fill both blanks to complete the providers array with GitHub and its clientId and clientSecret.

NextJS

providers: [GitHub({ clientId: process.env.[1], clientSecret: process.env.[2] })]

Drag options to blanks, or click blank then click option'

AGITHUB_ID

BGITHUB_SECRET

CGITHUB_CLIENT

DGITHUB_KEY

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect environment variable names like 'GITHUB_CLIENT'.

Swapping clientId and clientSecret values.

The environment variables for GitHub OAuth are usually named GITHUB_ID and GITHUB_SECRET.

5fill in blank

hard

Fill all three blanks to add a secret, enable debug mode, and set a custom session strategy.

NextJS

export default NextAuth({ providers, secret: process.env.[1], debug: [2], session: { strategy: '[3]' } });

Drag options to blanks, or click blank then click option'

ANEXTAUTH_SECRET

Btrue

Cjwt

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'false' for debug when intending to enable it.

Setting session strategy to an invalid value.

The secret is stored in NEXTAUTH_SECRET. Debug mode is enabled with true. The session strategy can be set to jwt for JSON Web Tokens.

Practice

1. What is the main purpose of NextAuth.js in a Next.js application?

easy

A. To optimize images automatically

B. To manage database connections

C. To style components with CSS

D. To handle user authentication and login flows easily

Solution

1. Step 1: Understand NextAuth.js role

   NextAuth.js is a library designed to simplify adding authentication to Next.js apps.

2. Step 2: Identify main functionality

   It manages login flows, sessions, and providers for user authentication.

3. Final Answer:

   To handle user authentication and login flows easily -> Option D

4. Quick Check:

   NextAuth.js = Authentication helper [OK]

Hint: NextAuth.js is all about login and user sessions [OK]

Common Mistakes:

• Confusing NextAuth.js with styling or database tools
• Thinking it manages images or CSS
• Assuming it handles API routing unrelated to auth

2. Which file path is the correct place to create the NextAuth.js API route in a Next.js app?

easy

A. /pages/api/auth/[...nextauth].js

B. /pages/auth/nextauth.js

C. /api/auth.js

D. /pages/api/nextauth.js

Solution

1. Step 1: Recall NextAuth.js API route convention

   NextAuth.js requires a catch-all API route named [...nextauth].js inside /pages/api/auth/.

2. Step 2: Match the correct path

   Only /pages/api/auth/[...nextauth].js matches the required path: /pages/api/auth/[...nextauth].js.

3. Final Answer:

   /pages/api/auth/[...nextauth].js -> Option A

4. Quick Check:

   API route = /api/auth/[...nextauth] [OK]

Hint: NextAuth.js uses catch-all API route [...nextauth].js [OK]

Common Mistakes:

• Placing the file outside /api/auth/
• Using a non-catch-all filename
• Missing the brackets in filename

3. Given this NextAuth.js configuration snippet, what will be the value of session.user.name after a successful login?

import NextAuth from "next-auth";
import GithubProvider from "next-auth/providers/github";

export default NextAuth({
  providers: [
    GithubProvider({
      clientId: process.env.GITHUB_ID,
      clientSecret: process.env.GITHUB_SECRET
    })
  ],
  callbacks: {
    async session({ session, user }) {
      session.user.name = "CustomName";
      return session;
    }
  }
});

medium

A. The GitHub username

B. "CustomName"

C. Undefined

D. The user's email

Solution

1. Step 1: Understand the session callback

   The session callback modifies the session object before it is returned to the client.

2. Step 2: Check the modification

   It sets session.user.name explicitly to "CustomName" regardless of original data.

3. Final Answer:

   "CustomName" -> Option B

4. Quick Check:

   Session callback overrides user.name = "CustomName" [OK]

Hint: Session callback can override user data before sending [OK]

Common Mistakes:

• Assuming user.name stays as GitHub username
• Thinking session.user.name is undefined by default
• Confusing email with name property

4. You wrote this NextAuth.js provider config but get an error: TypeError: GithubProvider is not a function. What is the likely cause?

import { GithubProvider } from "next-auth/providers/github";

export default NextAuth({
  providers: [
    GithubProvider({
      clientId: process.env.GITHUB_ID,
      clientSecret: process.env.GITHUB_SECRET
    })
  ]
});

medium

A. Provider config must be inside callbacks

B. Missing environment variables

C. Incorrect import syntax; should use default import without braces

D. NextAuth must be imported from 'next-auth/client'

Solution

1. Step 1: Check import style for GithubProvider

   GithubProvider is the default export, so it should be imported without braces.

2. Step 2: Identify correct import syntax

   Use import GithubProvider from "next-auth/providers/github"; instead of curly braces.

3. Final Answer:

   Incorrect import syntax; should use default import without braces -> Option C

4. Quick Check:

   Default export = no braces in import [OK]

Hint: Default exports import without braces {} [OK]

Common Mistakes:

• Using named import syntax for default export
• Assuming environment variables cause this error
• Placing provider config inside callbacks

5. You want to add Google and GitHub login providers in NextAuth.js with environment variables. Which is the correct way to configure both providers in /pages/api/auth/[...nextauth].js?

hard

A. import GoogleProvider from "next-auth/providers/google";
import GithubProvider from "next-auth/providers/github";

export default NextAuth({
providers: [
GoogleProvider({ clientId: process.env.GOOGLE_ID, clientSecret: process.env.GOOGLE_SECRET }),
GithubProvider({ clientId: process.env.GITHUB_ID, clientSecret: process.env.GITHUB_SECRET })
]
});

B. import { GoogleProvider, GithubProvider } from "next-auth/providers";

export default NextAuth({
providers: [
GoogleProvider(process.env.GOOGLE_ID, process.env.GOOGLE_SECRET),
GithubProvider(process.env.GITHUB_ID, process.env.GITHUB_SECRET)
]
});

C. import GoogleProvider from "next-auth/providers/google";
import GithubProvider from "next-auth/providers/github";

export default NextAuth({
providers: {
google: GoogleProvider,
github: GithubProvider
}
});

D. import GoogleProvider from "next-auth/providers/google";
import GithubProvider from "next-auth/providers/github";

export default NextAuth({
providers: [
GoogleProvider,
GithubProvider
]
});

Solution

1. Step 1: Import providers correctly

   Each provider is a default export from its own module and must be imported separately.

2. Step 2: Configure providers as array with clientId and clientSecret

   Providers must be called as functions with an object containing clientId and clientSecret from environment variables.

3. Step 3: Validate options

   import GoogleProvider from "next-auth/providers/google"; import GithubProvider from "next-auth/providers/github"; export default NextAuth({ providers: [ GoogleProvider({ clientId: process.env.GOOGLE_ID, clientSecret: process.env.GOOGLE_SECRET }), GithubProvider({ clientId: process.env.GITHUB_ID, clientSecret: process.env.GITHUB_SECRET }) ] }); correctly imports and configures both providers in an array with proper keys.

4. Final Answer:

   Correct import and provider function calls with env variables -> Option A

5. Quick Check:

   Providers array with clientId/clientSecret = import GoogleProvider from "next-auth/providers/google"; import GithubProvider from "next-auth/providers/github"; export default NextAuth({ providers: [ GoogleProvider({ clientId: process.env.GOOGLE_ID, clientSecret: process.env.GOOGLE_SECRET }), GithubProvider({ clientId: process.env.GITHUB_ID, clientSecret: process.env.GITHUB_SECRET }) ] }); [OK]

Hint: Providers need clientId and clientSecret in array [OK]

Common Mistakes:

• Importing providers as named imports from a single module
• Passing env vars directly without object keys
• Using object instead of array for providers