This article will teach you all you need to know about Node.js with Deno, including the differences between CommonJS modules and ECMAScript modules, how to utilise TypeScript with Deno, and how to use Deno Deploy to speed up deployments.

What is Node?

Node.js is a JavaScript runtime environment that can be used for both server and desktop applications regardless of the platform they are being executed on. A JavaScript callback function is triggered whenever a new connection is made, and this is accomplished by running a single-threaded event loop that has been registered with the system.

The use of JavaScript is optional in Node applications. TypeScript and CoffeeScript are only two examples of languages that transpile to JavaScript. The Google Chrome V8 JavaScript engine is a part of Node.js, and it fully supports the ECMAScript 2015 (ES6) syntax without the requirement for an ES6-to-ES5 transpiler like Babel.

The NPM command provides easy access to Node's extensive package library. Node.js comes with the Node Package Manager (NPM), which also has its own webpage.

What is Deno?

Deno is a safe runtime environment for TypeScript and JavaScript that has been expanded to include support for JavaScript XML (JSX) as well as the TSX extension for TypeScript. Deno is an effort to rethink Node in order to harness developments in JavaScript that have occurred since 2009, such as the TypeScript compiler.

Deno is comparable to Node.js in that it is simply a wrapper or shell over the Google V8 JavaScript engine. It differs from Node in that the TypeScript compiler is already included into its executable image.

According to Dahl, who is responsible for creating both runtimes, Node.js has three significant flaws: a poorly designed module system that is reliant on centralised distribution; a large number of old APIs that need to be maintained; and an absence of security. These errors are addressed in the Deno.

Is Deno superior for security?

It's well known that Deno has superior security over Node. This is mostly due to the fact that by default, a Deno application cannot interact with the file system, the network, other processes, or the environment.

This flag can be as general or specific as you need it to be. Deno's ability to terminate on uncaught mistakes is another measure taken to strengthen its security. In contrast, if an error is not noticed by Node, execution will continue anyway, perhaps leading to unexpected outcomes.

Compatibility of Typescript with Deno

Deno considers TypeScript a "equal-to" language, on par with JavaScript and WebAssembly. Deno's built-in TypeScript compiler and the swc Rust library are used to transform TypeScript (and TSX and JSX) into JavaScript. Code is cached after it has been converted and type-checked (if checking is enabled). That is to say, the tsc compiler is not required to manually transpile TypeScript for Deno, in contrast to Node.js or a browser.

Deno 1.23 removed built-in TypeScript type checking. Since most developers already use their editor to interact with the type-checker, it is not necessary for Deno to do a second type-check at startup. Deno's check option allows you to activate type checking.

Modules for CommonJS and ECMAScript

CommonJS was the de facto standard for JavaScript modules at the time Node was developed, and hence it was the first format supported by npm. Since then, the ECMAScript committee has given its approval to ECMAScript modules (also known as ES modules), which are compatible with the jspm package manager. Deno has a built-in ES module support as well.

With Node.js 12.12, experimental support for ES modules was enabled; from Node.js 16 forward, this support has been stabilised. TypeScript 4.7 allows for Node.js 16 ES modules as well. The need statement is how a CommonJS module may be loaded into JavaScript. When loading an ECMAScript module, the import statement and its corresponding export statement are used.

The most current Node.js release has module loaders for both CommonJS and ES. What are the fundamental differences between them? The CommonJS loader is asynchronous, tries to supply missing file extension information to the require() method (.js,.json, or.node), and accepts directories as modules.

CommonJS does not allow ECMAScript module loading. The .js,.mjs, and .cjs extensions for JavaScript text files are accepted by the ES modules loader; it is asynchronous; it is responsible for processing both import statements and import() expressions; it does not support folders as modules (directory indices such as./startup/index.js must be fully specified); and it does not search for extensions.

Deno for quicker deployments

Deno Deploy is a distributed solution that enables you to execute JavaScript, TypeScript, and WebAssembly near to users, at the edge, and globally. Deno Deploy servers, which are tightly integrated with the V8 runtime, enable low latency and reduce superfluous abstractions.

You can write your script locally using the Deno CLI and then deploy it to Deno Deploy managed infrastructure in less than a second, with no need for configuration.

Deno Deploy, built on the same current infrastructure as the Deno CLI, delivers the newest and best in web technologies in a globally scalable manner:

  1. Builds on the web: Just like in a browser, use fetch, WebSocket, or a URL.
  2. TypeScript and JSX support is built in, allowing for type-safe code and straightforward server-side rendering without the need for a build step.
  3. ECMAScript modules that are web-compatible: Import dependencies exactly as in a browser, without the need for explicit instals.
  4. GitHub integration: Push to a branch, examine a deployed preview, and merge to release to production.
  5. Extremely fast: Deploy in less than a second and serve worldwide near to users.
  6. Deploy from a URL: Deploy code using just a URL.

Deno Deploy has two levels. The free tier is restricted to 100,000 requests per day, 100 GiB data transfer per month, and 10ms CPU time each request.

The pro plan costs $10 per month and includes 5 million requests per month and 100 GB data transfer, plus $2 per million extra requests per month and $0.30/GB data transfer over the specified limit; the pro tier permits 50 ms CPU time per request.

Is it possible to combine Node with Deno?

For server-side JavaScript applications, both Node.js and Deno are viable solutions. Is it feasible, however, to mix them? The answer is a definitive maybe.

The first thing to mention is that Deno Node packages often operate well. Fortunately, most of the usual stumbling hurdles have solutions. Deno standard library modules may also be used to "polyfill" Node's built-in modules; CDNs can be used to retrieve npm packages in Deno-compatible ways; and import maps can be utilised. Deno has also supported Node compatibility mode since version 1.15.

However, Deno does not support Node's plugin system; Deno's Node compatibility mode does not support TypeScript; and a few Node modules (such as VM) do not work with Deno.

Which is better, Node or Deno?

As you would assume, the answer to which technology is best for your use case is influenced by a variety of variables. My conclusion: if your present Node.js deployment isn't broken, don't fix it. If you're starting a new project in TypeScript, I'd recommend looking at Deno.

However, if your TypeScript project requires the usage of many Node.js packages that do not have Deno counterparts, you must consider the practicality of the Deno project. Starting with a proof-of-concept is almost always required: It's difficult to tell if a certain Node.js package will function in Deno without testing it.

Author:

Dianna Perry is the dedicate WordPress developer at CMARIX TechnoLabs Pvt. Ltd., a Node.js development company with years of experience.