If you are using Node.js but don’t like its package manager npm, or want a more secure Javascript runtime environment than Node.js, then Deno is for you. It is a program for running Javascript and Typescript code outside of a browser. It is an attempt to reimagine Node.js with the advances in Javascript since 2009, including Typescript compiler. Like Node.js, Deno is basically a shell around the Google V8 JavaScript engine, although dissimilar to Node.js it includes the TypeScript compiler for its executable image. If you are still confused between Deno and Node.js, then this article is for you. Here we’ll discuss the comparison of Deno and Node.js. But before digging to the comparison let’s see the overview of each one.
It executes Typescript and JavaScript to asynchronous desktop servers and apps. Deno is the new implementation which uses modern features of JS language. It is a secure runtime for Typescript and Javascript that uses Google’s V8 and core is built in Rust. Here are some of the advantages of Deno.
Node.js is a server-side javascript environment, based on Google’s JS engine. It is focused on the event-driven HTTP servers. Node.js is an easy-to-built platform which is a scalable and fast network application. It has an event-driven I/O model and non-blocking Node.js which makes it highly efficient. Also, it is a great solution for data-intensive and real-time apps that can run on distributed devices.
Know the amazing new features of Node.js 16 at- What’s New In Node.js 16?
Deno-
It supports ES2020 features like Promise.allSettled() and globalThis keyword. ECMAScript modules are default, with CommonJS modules not supported unless you use Node compatibility library. TypeScript is supported as a first-class language in Deno, means it works out-of-the-box: no need for installing extra tools to transpile to JavaScript first. Obviously, the V8 engine doesn’t support TypeScript natively, so Deno is as yet transpiling the code, however this is all consistent and transparent to you as a developer.
Node.js-
Latest Node release supports modern Javascript syntax and features. Also, it supports 75% of the ES2020 spec. Also, ECMAScript modules are supported, but are now only classed as experimental: you have to use the .mjs file extension, or add the property “type”: “module” to your project’s package.json file. To run TypeScript on Node, the code should be compiled to Javascript that V8 engine can execute. There are various ways to do this, with different pros and cons. Hence you should choose of these and follow the necessary setup process.
It is one of the biggest advantages of Deno. Deno does away with need for package manager. Rather than, packages are linked to directly through a URL-
import { Response } from "https://deno.land/std@0.53.0/http/server.ts";
When you run the code first time, Deno fetches and compiles all the dependencies. Then, they are catched on the file system, independently from your project, so subsequent runs are much faster. Just like npm’s package-lock.json file, Deno lets you to specify a lock file that will be used to ensure that only dependencies that match the exact version you originally imported will be used.
Node.js comes with its own package manager known as npm, that is used to install and manage third-party packages. Npm is used with an online npm registry, where available third-party packages are listed. While using npm to install a package into a project, a package.json file is used to specify the package name and acceptable version range. Then the package is downloaded into a node_modules folder inside your project.
API of Deno has been designed to leverage the modern Javascript features. Deno supports top level await, means you can use await in your main script without having to wrap it in an async function.
try { const data = await Deno.readFile('readme.txt'); // Handle the data } catch (e) { // Handle the error }
According to the development team they’ve implemented browser APIs where it is possible to do so. Deno provides a global window object and APIs like addEventListener and fetch. If you’re having access to fetch, it is great, because with Node you’d have to polyfill this or use third-party library. Deno provides a compatibility layer to allow you to reuse existing Node packages. Now, it support loading CommonJS modules through require(), among other things.
When Node was released, there was no built-in support for promises. So, most of the APIs for asynchronous operations were written to take an error-first callback:
const fs = require('fs'); fs.readFile('readme.txt', (err, data) => { if (err) { // Handle the error } // Otherwise handle the data });
Now Node developer have access to Promises and the async/await syntax, but still the APIs expect callbacks to maintain backwards compatibility.
Security is the main point of Deno. It provides command-line flag ‘-allow-net’ to give access to all external permissions for the script. Also it uses command-line arguments to enable or disable access to security features. Deno provides code to read from the folder, that provides a security exception. As a part of command line Flags execute the script that provides permissions needed for code. Deno won’t delete files from your program without your permission, also won’t able to access the hard drive or execute any potentially malicious activities without permission.
Nodejs-
Node runtime is very permission. It allows complete access to the computer’s network and file system. There is capability for third-party code to wreak havoc on your system if unchecked.
Deno is trying to avoid the need for a package manager or registry,by allowing scripts to import modules directly from any public URL. It is not easy to import packages if you don’t know what’s there, hence Deno website maintains compatible third-party modules. To improve the developer experience there is provision of standard library of helpers and utilities for common tasks. All modules are audited to ensure high-quality, dependable code. There are some modules available for processing command line arguments and colorizing terminal output.
Node has a large ecosystem of libraries and packages. Since its release, over a million packages have been registered on the npm registry. Hence quality can vary a lot and many are no longer actively maintained but still benefits developers.
As compared to Node.js, Deno is new in the market and they are still working on its features. It has cool features but still needs to work on their browser compatibility as they are still implementing the browsers APIs. Meaning that you have to hire Node.js developers to build great platforms using great technology support. It is best suitable to develop apps like social media apps, multiplayer games, API, streaming apps, chat programs, real-time web apps etc.