Harnessing the Power of Deno: The JavaScript and TypeScript Runtime published 8/29/2023 | 4 min read

Welcome to the era of Deno, a secure runtime for JavaScript and TypeScript. Initially, you might associate it closely with Node.js due to the creator being the same individual, Ryan Dahl. However, Deno seeks to improve where Node.js fell short, one of them being security. In this comprehensive guide, we'll walk you through Deno's strengths, how to get started, compare it with Node.js, and show how it can be part of your toolset.

Table of Contents

Deno: An Introduction

Deno is a simple, modern and secure runtime for JavaScript and TypeScript that uses V8 and is built in Rust. It was created to address the design flaws of Node.js, offering first-class promise-based asynchronous APIs and integrated TypeScript support, out of the box.

Forestalling several security pitfalls common in Node.js, Deno runs in a secured sandbox environment by default unless explicit permission is granted.

  
deno run --allow-read server.js

With this command, the script will only have read access.

Key Features of Deno

  1. Top-Level Async/Await: Deno supports top-level await in its scripts, simplifying asynchronous programming.
  2. Secure by Default: Deno runs scripts in a restricted sandbox environment by default.
  3. Built-in Dependency Inspector: Deno provides built-in tools for code introspection, such as 'deno info'.
  4. Test Runner: It ships with a built-in test runner, allowing developers to efficiently test their Deno scripts.
  5. Browser Compatible APIs: Deno mirrors APIs provided by modern browsers, such as fetch and window object.
  6. Integrated Package Manager: There's no need for external tools like npm or yarn. Modules are downloaded and cached upon their first usage, and thereafter they are imported directly from the URL.
  7. Integrated TypeScript: No setup required. Deno can understand TypeScript out of the box, taking JavaScript development to the next level.

Understanding Deno's JavaScript and TypeScript Support

Deno supports both JavaScript and TypeScript right out of the box; you don't need to set up any additional tooling to use TypeScript. This takes away the need for a complex build process to transpile TypeScript to JavaScript before execution, as shown in the example below:



  
type Greeting = {
  text: string;
};
  
const helloWorld: Greeting = {
  text: "Hello, Devspedia!",
};
  
console.log(helloWorld.text);

With the file saved as 'hello.ts', you can run this directly using Deno:

  
deno run hello.ts

Installing and Getting Started with Deno

You can install Deno in your system using shell:

  
curl -fsSL https://deno.land/x/install/install.sh | sh

or using PowerShell:

  
iwr https://deno.land/x/install/install.ps1 -useb | iex

Once installed, create a 'hello.ts' file to taste Deno's TypeScript functionality:

  
console.log("Welcome to Deno, devspedia reader!");

Then run the file using Deno:

  
deno run hello.ts


Deno vs Node.js: The Showdown

While Node.js has a significant history and massive user base, Deno comes with several features that make it a worthy competitor. The security-focused, promise-ready, and TypeScript support out-of-the-box aspects of Deno make it a strong alternative. However, choosing between them boils down to the needs of your project and familiarity with the environments.

Conclusion

As we wrap up this guide, it's evident that Deno brings a lot to the table, addressing pain points present in Node.js. This makes it an interesting choice for JavaScript and TypeScript developers. However, as with any new technology, it will take time for Deno to mature and gain traction. It's an exciting time in the world of JavaScript and TypeScript development - keep exploring and happy coding!



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