Zero bundle size for server components in NextJS - Mini Project: Build & Apply

Zero Bundle Size for Server Components in Next.js

📖 Scenario: You are building a simple Next.js app that shows a list of books. You want to use server components to keep the client bundle small and fast.

🎯 Goal: Create a Next.js app with a server component that fetches and displays a list of books. Ensure the component does not add any client-side JavaScript bundle.

📋 What You'll Learn

Create a server component named BooksList that fetches book data.

Use a constant array books with exact book titles and authors.

Render the list of books inside a semantic <section> with a heading.

Export the component as default and ensure it is a server component by using the export const dynamic = 'force-static' directive.

💡 Why This Matters

🌍 Real World

Server components help keep your Next.js app fast by sending only HTML to the client, reducing JavaScript bundle size and improving load times.

💼 Career

Understanding server components and zero bundle size is important for building scalable, high-performance web apps in modern React and Next.js development.

1

Create the books data array

Create a constant array called books with these exact objects: { title: 'The Great Gatsby', author: 'F. Scott Fitzgerald' }, { title: '1984', author: 'George Orwell' }, and { title: 'To Kill a Mockingbird', author: 'Harper Lee' }.

NextJS

// Create the books array with exact objects
// Your code here

Hint

Use const books = [ ... ] with exact objects inside the array.

2

Add a dynamic export to enforce static rendering

Add the line export const dynamic = 'force-static' below the books array to ensure the component is treated as a server component with zero client bundle.

NextJS

const books = [
  { title: 'The Great Gatsby', author: 'F. Scott Fitzgerald' },
  { title: '1984', author: 'George Orwell' },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee' }
];

// Add export const dynamic = 'force-static' below
// Your code here

Hint

Write exactly export const dynamic = 'force-static' to mark the component as static.

3

Create the BooksList server component

Create a default exported async function component named BooksList that returns a <section> containing an <h2> with text Book List and an unordered list <ul> with each book's title and author in a <li>. Use books.map with book as the iterator variable.

NextJS

const books = [
  { title: 'The Great Gatsby', author: 'F. Scott Fitzgerald' },
  { title: '1984', author: 'George Orwell' },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee' }
];

export const dynamic = 'force-static';

// Create default async function BooksList() returning JSX
// Your code here

Hint

Use export default async function BooksList() and return JSX with a section, heading, and list using books.map.

4

Complete the component with accessibility and export

Add an aria-label attribute with value List of books to the <ul> element for accessibility. Confirm the component is exported as default and uses the dynamic export.

NextJS

const books = [
  { title: 'The Great Gatsby', author: 'F. Scott Fitzgerald' },
  { title: '1984', author: 'George Orwell' },
  { title: 'To Kill a Mockingbird', author: 'Harper Lee' }
];

export const dynamic = 'force-static';

export default async function BooksList() {
  return (
    
      Book List
      
        {books.map((book) => (
          {book.title} by {book.author}
        ))}
      
    
  );
}

// Add aria-label to ul for accessibility
// Your code here

Hint

Add aria-label="List of books" to the <ul> for screen readers.

Practice

1. What is the main benefit of using server components in Next.js with zero bundle size?

easy

A. They send no JavaScript to the browser, reducing bundle size and improving load speed.

B. They allow client-side interactivity without any server code.

C. They automatically cache data on the client for offline use.

D. They enable real-time updates without refreshing the page.

Solution

1. Step 1: Understand server components behavior

   Server components run only on the server and do not send JavaScript to the browser.

2. Step 2: Identify the benefit of zero bundle size

   Because no JavaScript is sent, the bundle size is smaller, which improves page load speed.

3. Final Answer:

   They send no JavaScript to the browser, reducing bundle size and improving load speed. -> Option A

4. Quick Check:

   Zero bundle size = faster load [OK]

Hint: Server components send zero JS to browser, so bundle size shrinks [OK]

Common Mistakes:

• Thinking server components run on the client
• Assuming server components add client interactivity
• Confusing caching with zero bundle size

2. Which of the following is the correct way to declare a server component in Next.js to ensure zero bundle size?

easy

A. "use client"; export default function MyComponent() { return <div>Hello</div>; }

B. "use server"; export default function MyComponent() { return <div>Hello</div>; }

C. export default function MyComponent() { return <div>Hello</div>; }

D. import React from 'react'; export default function MyComponent() { return <div>Hello</div>; }

Solution

1. Step 1: Identify server component syntax

   By default, components without "use client" directive are server components in Next.js.

2. Step 2: Check the options for client/server directives

   export default function MyComponent() { return <div>Hello</div>; } has no "use client" directive, so it is a server component with zero bundle size.

3. Final Answer:

   export default function MyComponent() { return <div>Hello</div>; } -> Option C

4. Quick Check:

   No "use client" means server component [OK]

Hint: No "use client" means server component with zero bundle size [OK]

Common Mistakes:

• Adding "use client" which makes it a client component
• Using "use server" which is not a valid directive
• Assuming import React affects server/client distinction

3. Given this Next.js server component code, what will be sent to the browser?

export default function Greeting() {
  const message = 'Hello from server';
  return <h1>{message}</h1>;
}

medium

A. An HTML <h1> element with text 'Hello from server' and no JavaScript bundle.

B. An empty page because server components do not render anything.

C. An HTML <h1> element plus JavaScript to hydrate the component on the client.

D. A JavaScript bundle only, no HTML content.

Solution

1. Step 1: Understand server component rendering

   Server components render HTML on the server and send only HTML to the browser, no JS bundle.

2. Step 2: Analyze the code output

   The component returns an <h1> with the message string, so the browser receives that HTML.

3. Final Answer:

   An HTML <h1> element with text 'Hello from server' and no JavaScript bundle. -> Option A

4. Quick Check:

   Server component sends HTML only [OK]

Hint: Server components send HTML only, no JS bundle [OK]

Common Mistakes:

• Thinking server components send JS for hydration
• Assuming server components render nothing
• Confusing client components with server components

4. You wrote this server component in Next.js:

"use client";
export default function UserName() {
  const name = fetchUserName();
  return <div>{name}</div>;
}

What is the main issue here?

medium

A. Missing async keyword on the function causes fetchUserName() to fail.

B. Using "use client" makes it a client component, but fetchUserName() is a server-only function causing an error.

C. Server components cannot return JSX elements.

D. The component will work fine with zero bundle size.

Solution

1. Step 1: Identify component type from directive

   "use client" makes this a client component, so server-only functions like fetchUserName() cannot run here.

2. Step 2: Understand server-only function usage

   fetchUserName() likely fetches data on the server, so calling it in a client component causes an error.

3. Final Answer:

   Using "use client" makes it a client component, but fetchUserName() is a server-only function causing an error. -> Option B

4. Quick Check:

   Client component cannot call server-only functions [OK]

Hint: Client components cannot run server-only functions [OK]

Common Mistakes:

• Forgetting "use client" changes component type
• Assuming fetchUserName() works on client
• Thinking async keyword fixes server/client mismatch

5. You want to build a Next.js page that fetches user data from a database and displays it without sending any JavaScript to the browser. Which approach ensures zero bundle size for this page?

hard

A. Fetch data in getStaticProps and pass it to a client component.

B. Create a client component with "use client" that fetches data using useEffect and displays it.

C. Create a server component but add "use client" to enable interactivity.

D. Create a server component that fetches data inside and returns JSX, without "use client" directive.

Solution

1. Step 1: Identify zero bundle size requirement

   Zero bundle size means no JavaScript sent to browser, so no client components.

2. Step 2: Choose correct data fetching method

   Fetching data inside a server component without "use client" sends only HTML with data, no JS bundle.

3. Step 3: Evaluate other options

   Client components or getStaticProps with client components send JS bundles, so they don't meet zero bundle size.

4. Final Answer:

   Create a server component that fetches data inside and returns JSX, without "use client" directive. -> Option D

5. Quick Check:

   Server component + data fetch = zero bundle size [OK]

Hint: Use server component with data fetch, no "use client" [OK]

Common Mistakes:

• Adding "use client" which sends JS bundle
• Using client-side data fetching hooks
• Assuming getStaticProps alone ensures zero bundle size