What is Deno

overview

Deno is a new JavaScript and TypeScript runtime that also draws attention when compared to Node.js. This chapter goes from a basic introduction to Deno, to its comparison with Node.js, its advantages, and its architecture in detail.

Overview of Deno

Deno is a JavaScript and TypeScript execution environment developed by Ryan Dahl. Built with the V8 JavaScript engine and Deno’s custom runtime, Deno features the same security-focused design as the browser. Deno can be used to run server-side and client-side JavaScript and TypeScript applications.

Deno features include:

  • Security: Deno restricts external network access and file system access by default and requires explicit permissions to be granted. This helps mitigate security vulnerabilities due to malicious code execution and access control mistakes.
  • Module management: Deno uses URLs to import modules. External modules can be imported directly, eliminating the need for package manager or package registry dependencies.
  • Asynchronous processing: Deno focuses on asynchronous processing and supports modern asynchronous patterns such as promises and async/await to eliminate problems like Callback Hell.

Comparison with Node.js

Deno and Node.js are both JavaScript and TypeScript execution environments, but they differ in some respects. First, Node.js is a mature platform that has been around for a long time and is widely supported. Deno, on the other hand, is a relatively new platform with a unique approach to things like security and module management.

Here are some comparisons between Deno and Node.js:

  • Package management: Node.js uses npm extensively, but Deno allows you to import external modules directly using URLs for module imports. This eliminates the need for dependency management and the use of package registries.

  • Security: Deno takes security seriously and restricts external network access and file system access by default. Node.js, on the other hand, has no such restrictions, but you should be careful.

  • Asynchronous processing: Deno is focused on asynchronous processing and supports modern asynchronous patterns such as promises and async/await. Node.js also supports asynchronous processing, but callback-based APIs are the mainstream.

Benefits of Deno

Deno’s advantages can be summarized as follows:

  • Security: Deno restricts external network access and file system access by default and requires explicit permissions to be granted. This helps mitigate malicious code execution and security vulnerabilities.

  • Module management: Deno uses URLs to import modules. External modules can be imported directly, eliminating the need for package manager or package registry dependencies.

  • Asynchronous processing: Deno focuses on asynchronous processing and supports modern asynchronous patterns such as promises and async/await to eliminate problems like Callback Hell.

  • TypeScript Support: Deno natively supports TypeScript. Using TypeScript allows for static type checking and improved code maintainability.

Deno Architecture

Deno’s architecture is built on the V8 JavaScript engine and Deno’s custom runtime. Below are the key elements of Deno’s architecture:

  • V8 JavaScript Engine: V8 is an open-source JavaScript engine developed by Google that enables fast JavaScript code execution.

Make it possible. Deno uses V8 to run JavaScript and TypeScript code.

  • Deno’s Custom Runtime: Deno’s Custom Runtime builds on the V8 JavaScript engine and adds features such as security and module management. A custom runtime implements Deno’s core modules and security restrictions.

  • Rust: Deno’s custom runtime is written in the Rust programming language. Rust is a language focused on safety, concurrency, and improved performance, and plays a key role in Deno’s custom runtime implementation.

Deno’s architecture emphasizes modularity and extensibility, providing a flexible and easy-to-use environment for developers.

How to build a Deno environment →