Install spirit and spirit-router:

$ npm install spirit spirit-router

Start off with a simple app:

const {adapter} = require("spirit").node
const route = require("spirit-router")

const hello = () => {
  return "Hello World!"
}

const app = route.define([
  route.get("/", [], hello)
])

const http = require("http")
const server = http.createServer(adapter(app))
server.listen(3000)

If we run our example and visit http://localhost:3000 in a browser, you will be greeted with Hello World!

Separation of code

Our hello() function is just a normal javascript function, what gets returned is what is sent back as the response.

It does not need to deal with a req or res object.

Separation of concerns is a central concept to spirit.

If we think about a web request in it's simpliest form, it's basically a function, it takes a input (request) and returns an output (response). So why not write web applications this way?

spirit simplifies everything by abstracting away the complexity of req and res that normally resulted in impure and complex functions.

Routes as definitions

Routes in spirit should be thought of as definitions and not some proprietary operation to perform.

  route.get("/", [], hello)

When we defined this route, do not think of hello as a "routing function".

When we define a route, we are simply describing the when and how. When should we call hello, and how to call it.

Routes in spirit serve as a boundary between http related ideas and regular javascript.

Adapter

const server = http.createServer(adapter(app))
server.listen(3000)

spirit has a concept of an adapter where most of the abstractions happen.

spirit comes with an adapter already for node.js. It converts our routes and app into something node.js's http module can understand.

It can optionally take middlewares adapter(app, _middleware_) (more on that in Using Middleware).