🌟 Build a Lightning-Fast API with Bun in Minutes!

Looking to build a super fast API? Meet Bun—a sleek, high-performance JavaScript runtime that’s making waves in the dev community. In this blog post, I’m going to show you how to create a simple API using Bun that’s fast and easy to set up.🎉

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What’s Bun? 🤔

Bun is a super-fast JavaScript runtime that’s optimized for speed. It comes with built-in features like a bundler, transpiler, and web server. Basically, it’s everything you need in one package—no more juggling multiple tools! ⚡

If you're tired of slow build times, Bun’s got you covered. Let’s dive in! 😎

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Step 1: Install Bun 📥

First things first—let’s get Bun installed on your machine. Just pop open your terminal and run:

powershell -c "irm bun.sh/install.ps1 | iex"

Once it's done, verify everything is working by running:

bun --version

You should see the Bun version pop up, and you're good to go! 🎉

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Step 2: Set Up Your Project 💻

Now, let’s set up your project folder. Create a new directory and jump in:

mkdir bun-api
cd bun-api
bun init

That’s it! You’re all set up with a fresh Bun project. 😄

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Step 3: Build Your API with Bun ⛅

Now that your project is ready, let’s write a simple API using Bun. In this example, we will create several endpoints like /products, /login, /cart, and more, along with a logging feature to track requests made to the server.

Here’s the code:

Bun.serve({
  fetch(req) {
    return new Response("Bun!");
  },
});

const server = Bun.serve({
  port: 8050,
  fetch(req) {
    const url = new URL(req.url);
    const method = req.method;  
    const timestamp = new Date().toISOString(); 
    const logMessage = `[${timestamp}] ${method} ${url.pathname}\n`;

    // Log request to the file 'log.txt'
    fs.appendFileSync("log.txt", logMessage);

    switch (url.pathname) {
      case "/":
        return new Response("Welcome to BarterX");

      case "/products":
        return new Response("Here are the products up for sale in BarterX");

      case "/login":
        return new Response("Login to BarterX");

      case "/signup":
        return new Response("Sign up to BarterX");

      case "/profile":
        return new Response("Trader Profile");

      case "/cart":
        return new Response("Your Shopping Cart is here");

      case "/checkout":
        return new Response("Let's start shipping");

      case "/orders":
        return new Response("Your Orders are here");

      case "/api/products":
        const apiData = [
          { id: 1, name: "Used Laptop", price: 300 },
          { id: 2, name: "Second-hand Bicycle", price: 50 },
        ];
        return new Response(JSON.stringify(apiData), {
          headers: { "Content-Type": "application/json" },
        });

      case "/categories":
        return new Response("Browse Categories");

      case "/chat":
        return new Response("Your Chat with fellow Traders");

      case "/contact":
        return new Response("Contact Us at");

      case "/about":
        return new Response(Bun.file("./public/about.html"), {
          headers: { "Content-Type": "text/html" },
        });

      case "/styles":
        return new Response(Bun.file("./public/style.css"), {
          headers: { "Content-Type": "text/css" },
        });

      default:
        return Response.json(
          { error: "Page not found", statusCode: 404 },
          {
            status: 404,
            headers: { "Content-Type": "application/json" },
          }
        );
    }
  },
});

// Server running message
console.log(`Server is running at http://localhost:${server.port}`);

Explanation of the Code:

• Logging: Every request made to the server is logged to a log.txt file, capturing the timestamp, HTTP method, and URL pathname.

• API Routes: The API serves various endpoints:

  • GET requests for paths like /products, /cart, /login, etc.

  • API Data: The /api/products route returns a list of products in JSON format.

  • Static Files: Routes like /about and /styles serve HTML and CSS files.

• Error Handling: If a route isn’t defined, the server returns a 404 response with a JSON error message.

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Step 4: Run Your API 🔥

Once your code is ready, run the server using:

bun index.js

Your API will be running on http://localhost:8050. 🎉

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Step 5: Test It Out 🚀

To test your new API, you can use Postman, cURL, or just open a browser.

• GET Request: Access http://localhost:8050/api/products and get a list of products in JSON format.

• Static File Serving: Access http://localhost:8050/about to see the HTML file you served.

Use the following cURL command to check if your /api/products endpoint is working:

curl http://localhost:8050/api/products

It will return:

[
  { "id": 1, "name": "Used Laptop", "price": 300 },
  { "id": 2, "name": "Second-hand Bicycle", "price": 50 }
]

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Step 6: Wrap Up ✨

You’ve just created a powerful and fast API using Bun! 🥳

To recap:

• Installed Bun: ✅

• Set up the project: 🎉

• Built the API: Including dynamic routes and static file serving 🚀

• Tested the API: 🧪

Bun makes it incredibly easy and fast to build APIs, and you can scale it up as needed. If you're building a small project or a large-scale application, Bun is a great choice!

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Next Steps 🚀

• Explore more: Check out Bun’s docs for advanced features like WebSockets and database integration! 📚

• Scale it up: Add user authentication, persistent storage, and more! 📈

Thanks for reading, and happy coding! Feel free to ask any questions or leave comments below! 💬