Express App Composition (The functional programming way)

server.js

const Express = require('express')
const _ = require('lodash-fp')

const { userController, userMessagesController, postController, pagesController } = require('./controllers')
const { middleware1, middleware2, errorHandler } = require('./middlewares')

const use = (...middleware) => app => app.use(...middleware)

const setupRoute = _.curry((verb, method, urlParams, resource, controller, app) => app[verb](resource + urlParams, controller[method]))

const routeGroup = _.curry((endpoints, resource, controller, app) => { 
  endpoints.map(x => x(resource, controller, app))
  return app  
})

const _getAll = setupRoute('get', 'getAll', '')
const _post = setupRoute('post', 'new', '')
const _update = setupRoute('put', 'update', `/:id`)
const _delete = setupRoute('delete', 'delete', `/:id`)
const _get = setupRoute('get', 'get', `/:id`)

const rwEndpoints = routeGroup([ _getAll, _get, _post, _update, _delete ])
const roEndpoints = routeGroup([ _getAll, _get ])

const composeApp = _.flow(
  use(middleware1),
  use(middleware2),
  rwEndpoints('/user/message', userMessagesController),
  rwEndpoints('/user', userController),
  rwEndpoints('/posts', postController),
  roEndpoints('/pages', pagesController),
  use(errorHandler),
)

const app = composeApp(Express())
app.listen(3000, () => console.log('Example app listening on port 3000!'))