Does Deno 2 really uncomplicate JavaScript?

Introduction

In this tutorial, we'll explore Deno 2.0, a modern JavaScript runtime that promises to simplify the development process. We will build a REST API using Deno 2.0 to assess whether it truly lives up to its claim of uncomplicating JavaScript. This guide will provide you with actionable steps and practical advice for working with Deno, making it easier to create real-world applications.

Step 1: Setting Up Deno

To start using Deno 2.0, you need to install it on your system.

• Go to the Deno website for installation instructions.

• You can install Deno via a package manager or by downloading it directly.

• Verify the installation by running the following command in your terminal:

  deno --version
  

  This command should display the current version of Deno installed on your machine.

Step 2: Creating a Simple REST API

Now that Deno is installed, let's create a simple REST API.

• Create a new directory for your project:

  mkdir my-deno-api
  cd my-deno-api
  

• Create a new file named server.ts:

  touch server.ts
  

• Open server.ts in your favorite code editor and add the following code to set up a basic server:

  import { serve } from "https://deno.land/std/http/server.ts";
  
  const s = serve({ port: 8000 });
  console.log("HTTP server is running. Access it at: http://localhost:8000/");
  
  for await (const req of s) {
      req.respond({ body: "Hello Deno!" });
  }
  

• Save the file and run the server with the following command:

  deno run --allow-net server.ts
  

• Open your browser and navigate to http://localhost:8000/ to see the message "Hello Deno!".

Step 3: Adding RESTful Endpoints

Next, we will enhance our API by adding RESTful endpoints.

• Modify server.ts to handle different HTTP methods:

  import { serve } from "https://deno.land/std/http/server.ts";
  
  const s = serve({ port: 8000 });
  console.log("Server running at http://localhost:8000/");
  
  for await (const req of s) {
      switch (req.method) {
          case "GET":
              req.respond({ body: "GET request received" });
              break;
          case "POST":
              req.respond({ body: "POST request received" });
              break;
          default:
              req.respond({ status: 405, body: "Method Not Allowed" });
      }
  }
  

• Restart the server to apply changes, and test the different endpoints using a tool like Postman or curl.

Step 4: Managing Dependencies

Deno handles dependencies more simply than Node.js, using URLs directly in your code.

• To add external dependencies, import them at the top of your server.ts file. For instance, to use a logging library, you might write:

  import { log } from "https://deno.land/x/log/mod.ts";
  

• Deno automatically fetches the dependency when you run your code.

Conclusion

In this tutorial, we set up Deno 2.0 and built a simple REST API, demonstrating how Deno can streamline JavaScript development. We covered installation, creating a server, adding RESTful endpoints, and managing dependencies.

Next Steps

• Explore more Deno features, such as file handling and database connections.
• Experiment with building more complex APIs or applications.
• Check out additional resources and tutorials to deepen your understanding of Deno.