The creator of Node.js, Ryan Dahl has authored a new framework for designing web applications. He went back and fixed some mistakes he made in hindsight, taking advantage of new technologies that were not available at the time he originally wrote Node. The result is Deno (pronounced DEH-no), a framework for writing “Node-like” web applications in TypeScript. Here, I will walk you through creating a basic web application with authentication.

Table of Contents

• Create Your Deno Application
• Build a Real Web Application with Deno
• Fill In Your Deno Application
• Add Authentication with Okta
• Run the Deno Application

You can find almost all the information you need at the Deno website—along with information on all the third-party libraries that are currently available for Deno. That is really the biggest drawback to the framework right now. It just hit version 1.0 on May 13th of 2020, so even though there are quite a few essential libraries, there are not nearly as many libraries as there are for Node. For those who are proficient in Node however, the transition to Deno should be pretty easy.

You can find the installation instructions at https://deno.land/#installation.

Create Your Deno Application

There aren’t any basic scaffolding libraries that I could find, so I just started with an empty folder. In the application’s root folder, create a file called index.ts that will be the starting point of your Deno application. You’ll use Opine, which is an Express clone for Deno to make building and routing easier.

One thing that is different about Deno is that there are no package managers for bringing in third-party libraries. You do this by using the library’s full URL. Do that at the top of the index.ts file, then set up a basic web application.

import { opine } from 'https://deno.land/x/opine@0.12.0/mod.ts';

const app = opine();

app.get('/', (req, res) => {
  res.send('Deno Sample');
});

app.listen(3000);
console.log('running on port 3000');

You can then run this very basic application by going to the terminal in the application’s folder and entering:

deno run -A index.ts

The -A is a shortcut for development purposes. Deno is completely locked down by default, so you’ll need to pass arguments to the run command to allow access like --allow-net to allow networking, and --allow-read to allow the application to read from the file system. The -A used here allows everything, effectively disabling all security. When you run this application and then go to http://localhost:3000 you should be greeted with Deno Sample on a blank page.

#deno #authentication #node #web-development #developer