Nexpresso

An Express middleware that turns your file directories into API endpoints.

Inspired by Next.js, so... thank you, next! (pun intended)

Getting started

Install Express and Nexpresso:

yarn add express nexpresso

You first need to create a root directory (e.g. /server) for your Nexpresso files. Then, as an example, to create GET /some/route, you create the file /server/some/route/GET.js. Inside GET.js, you have to export a handler function like so:

// Example 1
// server/some/route/GET.js
const greet = (req, res) => {
  return res.send('Hello world!');
};

module.exports = { handler: greet };

handler can also be an array of handler functions, in case you wish to add middlewares:

// Example 2
// server/some/route/GET.js
const log = (req, res, next) => {
  console.log('I am called!');
  next();
};

const greet = (req, res) => {
  return res.send('Hello world!');
};

module.exports = { handler: [log, greet] };

To set up nexpresso, simply import Nexpresso and pass it to app.use() as a middleware.

const path = require('path');

const express = require('express');
const bodyParser = require('body-parser');
const nexpresso = require('nexpresso');

const app = express();
const port = 8080;

app.use(bodyParser.json());

// set up Nexpresso
app.use(
  nexpresso({
    pathToServer: path.join(__dirname, './server'),
  })
);

app.listen(port, () => {
  console.log(`Server now listening at port ${port}`);
});

To test, run the file locally and visit http://localhost:8080/some/route. You should see "Hello World!" as a response.

For more use cases, see the tests and files in example.

Why?

Easier to find routes

Finding the entry points to an Express route is often painful. In Nexpresso, finding your routes is easy because GET /some/route is simply in the file /some/route/GET.js.

Avoid magical side effects from middlewares

In Express, by changing the order of routes, you can have middlewares affect parts of the app, which is a horrible design. Because you will then have middlewares defined hundreds of lines of code away or even worse, in other files. Nexpresso enforces that middlewares must either affect all endpoints (e.g. body-parser) or only one endpoint (e.g. validation, authentication).

Possibilities for more powerful features

Nexpresso's design opens up opportunities for more features. For one, in addition to exporting a handler, we could also export an OpenAPI json object. Then with express-openapi-validator, we could also provide validations for endpoints; with swagger-ui-express, we could serve the Swagger UI page.