Deno: A Secure Runtime for JavaScript and TypeScript
Deno is a modern runtime for JavaScript and TypeScript. It provides a secure and productive environment for building applications. Think of it as a powerful engine that runs your code, but with built-in protections and conveniences. It’s designed to address some of the challenges found in existing JavaScript runtimes.
What is Deno?
Deno builds on the success of JavaScript and TypeScript, but introduces several key improvements. It’s built on V8, the same engine that powers Chrome, ensuring excellent performance. However, unlike Node.js, Deno embraces modern web standards. It uses TypeScript out of the box, providing static typing and improved code maintainability. Crucially, Deno prioritizes security. By default, Deno programs don’t have access to the file system or network. You must explicitly grant these permissions when running a program.
Here’s a simple “Hello, World!” program in Deno:
console.log("Hello, World!");To run this, you would save it as hello.ts and execute deno run hello.ts in your terminal.
Why Use Deno?
Deno offers several advantages for developers. The default-deny security model significantly reduces the risk of malicious code accessing sensitive resources, which is a major step forward for JavaScript development. TypeScript is built-in, eliminating the need for separate build tools and simplifying development. Deno supports the latest ECMAScript standards, allowing you to use cutting-edge language features. It uses web APIs, making it easier to write code that works both in the browser and on the server. Deno includes a built-in package manager, test runner, and code formatter, streamlining the development workflow. No more npm or yarn unless you choose to use them. Top-level await allows for writing asynchronous code more cleanly.
Consider this example of fetching data from a URL:
const response = await fetch('https://example.com');
const data = await response.json();
console.log(data);This code is concise and readable thanks to the built-in await support.
Getting Started
Installing Deno is straightforward. The installation process varies depending on your operating system.
- macOS: Use Homebrew:
brew install deno - Windows: Download the installer from the Deno website.
- Linux: Follow the instructions on the Deno installation page.
After installation, verify the installation by running deno version in your terminal. This will display the installed Deno version.
To create a new Deno project, you can simply create a .ts or .js file. Deno automatically detects and runs these files. You can then use deno run <filename> to execute your code.
Learn More
Deno has a vibrant and growing community. Here are some resources to help you learn more:
- Deno Website: https://deno.land/ – The official website with documentation, tutorials, and news.
- Deno Manual: https://deno.land/manual/ – Comprehensive documentation covering all aspects of Deno.
- Deno Discord: https://discord.deno.land/ – A community chat server for asking questions and connecting with other Deno developers.
- Deno Examples: https://github.com/denoland/deno/tree/main/examples – A collection of example programs demonstrating various Deno features.