Redirect and rewrite in middleware in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import NextResponse from Next.js.

NextJS

import { [1] } from 'next/server';

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

Aredirect

BNextResponse

Crewrite

DuseMiddleware

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'redirect' or 'rewrite' as import instead of 'NextResponse'.

Trying to import a non-existent function like 'useMiddleware'.

The NextResponse is imported from 'next/server' to handle redirects and rewrites in Next.js middleware.

2fill in blank

medium

Complete the code to redirect users to '/login' if they are not authenticated.

NextJS

import { NextResponse } from 'next/server';

export function middleware(request) {
  const isAuth = false; // example check
  if (!isAuth) {
    return NextResponse.[1]('/login');
  }
  return NextResponse.next();
}

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

Aredirect

Brewrite

Cforward

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'rewrite' instead of 'redirect' causes the URL to stay the same.

Using non-existent methods like 'forward' or 'send'.

Use NextResponse.redirect() to send users to a different URL.

3fill in blank

hard

Fix the error in the middleware to rewrite the URL to '/dashboard' without changing the browser URL.

NextJS

import { NextResponse } from 'next/server';

export function middleware(request) {
  return NextResponse.[1]('/dashboard');
}

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

Arewrite

Bnavigate

Csend

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'redirect' changes the browser URL, which is not desired here.

Using non-existent methods like 'navigate' or 'send'.

Use NextResponse.rewrite() to change the destination internally without changing the URL shown in the browser.

4fill in blank

hard

Fill both blanks to check if the request pathname starts with '/admin' and redirect to '/login' if true.

NextJS

import { NextResponse } from 'next/server';

export function middleware(request) {
  const { pathname } = request.nextUrl;
  if (pathname.[1]('/admin')) {
    return NextResponse.[2]('/login');
  }
  return NextResponse.next();
}

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

AstartsWith

Bredirect

Cincludes

Drewrite

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'includes' instead of 'startsWith' may cause wrong matches.

Using 'rewrite' instead of 'redirect' changes the URL invisibly.

Use startsWith to check the beginning of the pathname and redirect to send the user to '/login'.

5fill in blank

hard

Fill all three blanks to rewrite requests from '/blog/:slug' to '/news/:slug' preserving the slug parameter.

NextJS

import { NextResponse } from 'next/server';

export function middleware(request) {
  const url = request.nextUrl.clone();
  if (url.pathname.[1]('/blog/')) {
    url.pathname = url.pathname.[2]('/blog', '/news');
    return NextResponse.[3](url);
  }
  return NextResponse.next();
}

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

AstartsWith

Breplace

Crewrite

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'redirect' changes the browser URL, which is not wanted here.

Using 'includes' instead of 'startsWith' may match wrong paths.

Check if the path starts with '/blog/', replace '/blog' with '/news' in the path, then rewrite the request to the new URL.

Practice

1. What is the main difference between a redirect and a rewrite in Next.js middleware?

easy

A. Rewrite changes the URL in the browser, redirect does not.

B. Redirect changes the URL in the browser, rewrite does not.

C. Redirect and rewrite both change the URL in the browser.

D. Neither redirect nor rewrite affect the URL in the browser.

Solution

1. Step 1: Understand redirect behavior

   A redirect sends the user to a new URL and updates the browser's address bar to that URL.

2. Step 2: Understand rewrite behavior

   A rewrite changes the content served without changing the URL shown in the browser.

3. Final Answer:

   Redirect changes the URL in the browser, rewrite does not. -> Option B

4. Quick Check:

   Redirect updates URL, rewrite keeps URL same [OK]

Hint: Redirect changes URL; rewrite keeps URL same [OK]

Common Mistakes:

• Thinking rewrite changes browser URL
• Confusing redirect with rewrite
• Assuming both always change URL

2. Which of the following is the correct way to perform a redirect in Next.js middleware?

easy

A. return NextResponse.redirect('/home');

B. return NextResponse.rewrite(new URL('/home', request.url));

C. return NextResponse.next('/home');

D. return NextResponse.redirect(new URL('/home', request.url));

Solution

1. Step 1: Check NextResponse.redirect syntax

   The redirect method requires a full URL object, created with new URL(path, base).

2. Step 2: Validate options

   return NextResponse.redirect(new URL('/home', request.url)); correctly uses new URL with request.url as base. return NextResponse.redirect('/home'); incorrectly passes a string instead of URL object.

3. Final Answer:

   return NextResponse.redirect(new URL('/home', request.url)); -> Option D

4. Quick Check:

   Redirect needs URL object [OK]

Hint: Use new URL(path, request.url) for redirects [OK]

Common Mistakes:

• Passing string directly to redirect
• Using rewrite instead of redirect
• Missing base URL in new URL()

3. Given this middleware code snippet, what will happen when a user visits '/dashboard'?

import { NextResponse } from 'next/server';
export function middleware(request) {
  if (request.nextUrl.pathname === '/dashboard') {
    return NextResponse.rewrite(new URL('/profile', request.url));
  }
  return NextResponse.next();
}

medium

A. User sees content from '/profile' but URL stays '/dashboard'.

B. User is redirected to '/profile' and URL changes.

C. User stays on '/dashboard' with original content.

D. Middleware throws an error due to incorrect syntax.

Solution

1. Step 1: Analyze rewrite usage

   The code uses NextResponse.rewrite to serve '/profile' content when URL is '/dashboard'.

2. Step 2: Understand rewrite effect on URL

   Rewrite changes content served but keeps the browser URL unchanged as '/dashboard'.

3. Final Answer:

   User sees content from '/profile' but URL stays '/dashboard'. -> Option A

4. Quick Check:

   Rewrite changes content, not URL [OK]

Hint: Rewrite serves new content but keeps URL same [OK]

Common Mistakes:

• Confusing rewrite with redirect
• Expecting URL to change on rewrite
• Assuming middleware throws error here

4. Identify the error in this middleware code that tries to redirect users from '/old' to '/new':

import { NextResponse } from 'next/server';
export function middleware(request) {
  if (request.nextUrl.pathname === '/old') {
    return NextResponse.redirect('/new');
  }
  return NextResponse.next();
}

medium

A. The condition should check request.url, not request.nextUrl.pathname.

B. Middleware must be async to use redirect.

C. Redirect requires a full URL object, not a string.

D. NextResponse.next() cannot be returned in middleware.

Solution

1. Step 1: Check redirect argument type

   NextResponse.redirect expects a URL object, not a string path.

2. Step 2: Validate other parts

   Condition and NextResponse.next() usage are correct; async not required here.

3. Final Answer:

   Redirect requires a full URL object, not a string. -> Option C

4. Quick Check:

   Redirect needs URL object, not string [OK]

Hint: Redirect needs new URL(path, request.url) [OK]

Common Mistakes:

• Passing string directly to redirect
• Making middleware async unnecessarily
• Checking wrong request property

5. You want to redirect users to '/login' if they visit any page except '/public' or '/login'. Which middleware code correctly implements this logic?

hard

A. if (!['/public', '/login'].includes(request.nextUrl.pathname)) {
return NextResponse.redirect(new URL('/login', request.url));
}
return NextResponse.next();

B. if (['/public', '/login'].includes(request.nextUrl.pathname)) {
return NextResponse.redirect(new URL('/login', request.url));
}
return NextResponse.next();

C. if (request.nextUrl.pathname !== '/public' || request.nextUrl.pathname !== '/login') {
return NextResponse.redirect(new URL('/login', request.url));
}
return NextResponse.next();

D. if (request.nextUrl.pathname === '/public' && request.nextUrl.pathname === '/login') {
return NextResponse.redirect(new URL('/login', request.url));
}
return NextResponse.next();

Solution

1. Step 1: Understand condition logic

   We want to redirect if the path is NOT '/public' or '/login'. Using !includes checks this correctly.

2. Step 2: Check each option's condition

   if (!['/public', '/login'].includes(request.nextUrl.pathname)) { return NextResponse.redirect(new URL('/login', request.url)); } return NextResponse.next(); correctly uses negation with includes. if (['/public', '/login'].includes(request.nextUrl.pathname)) { return NextResponse.redirect(new URL('/login', request.url)); } return NextResponse.next(); redirects only on '/public' or '/login' which is wrong. Options C and D have logical errors in conditions.

3. Final Answer:

   Option A code correctly redirects except for '/public' and '/login'. -> Option A

4. Quick Check:

   Use !includes for exclusion check [OK]

Hint: Use !includes to exclude paths for redirect [OK]

Common Mistakes:

• Using OR instead of AND in conditions
• Redirecting on allowed paths
• Incorrect logical negation