As first adopters tinker with Deno, many people are trying to figure out tooling that parallels what they’re used to in node. If you’re looking for a lightweight web application framework like express.js, you probably want to explore oak.

See oak on github

Note: Many of the examples in this post are taken from the github documentation!

What is Oak?

Oak is self-described as “A middleware framework for Deno’s http server, including a router middleware.”

To be completely transparent, oak is actually much more similar to koa for node than express.js, but express users should be very comfortable with oak.

Creating a Hello World App with Oak

To create a “Hello World!” app in deno with oak, we import Application from the oak module. You create a new instance of the app, add a handler for all requests that set the response body to "Hello World!", and then listen on a port.

Make sure to pin down the version of oak in your import statement! Here it’s pinned down to version 4.0.0.

import { Application } from 'https://deno.land/x/oak@v4.0.0/mod.ts';

const app = new Application();

app.use(ctx => {
  ctx.response.body = 'Hello World!';
});

await app.listen({ port: 8000 });

Now if you browse to http://localhost:8000, you should see our Hello world! message!

#deno #node #javascript #typescript #web-development