express-mockups-middleware

Requirements

You will need Node v6 or later version.

What

This is an express middleware. This middleware purpose is to serve mockups on proxified HTTP requests. This is convenient during development to separate concerns.

Install

npm i --save-dev express-mockups-middleware

Use

You should pass an array of apis as first parameter of the middleware. api objects must respect the following structure.

Property | Required | Type | Description ----------|--------|---------------|------------- pattern | yes | String | A pattern that request.url property should match to be mocked. It will be passed as RegExp argument. enabled | no | Boolean | A boolean that determine if the middleware should handle this api. headers | no | Array of Objects | A array of objects ({key: '', value: ''}) that represents HTTP headers of the mocked response. status | no | Number | A number that will be the HTTP status of the mocked response. body | no | Function | A function that take as parameter the request object and should return a string that will be the message-body of the mocked response.

You can also add an optional configuration object as second parameter.

Parameter | Required | Default value | Description ----------|--------|---------------|------------- enabled | no | true | A boolean that determine if the middleware is enabled or not. force | no | false | Set to true it tells the middleware to ignore enabled property of apis objects. logger | no | empty function | Pass your own logger function that takes a string as parameter.

The middleware call next function of express when no pattern is matched. Otherwise the response is instantly sent to client.

Example

HTTP requests should be proxified otherwise the middleware won't work.

For it you could use http-proxy-middleware.

server.js

import express from 'express'
import proxy from 'http-proxy-middleware'
import mockups from 'express-mockups-middleware'

const app = express()
const resources = ['Resource1','Resource2'];

app.use(mockups([
  {
    pattern: '/resources',
    body: (req) => JSON.stringify(resources)
  },
  {
    pattern: '/resources/(.*)',
    body: (req) => {
      const segments = req.url.split('/')
      return resources[segments[segments.length - 1]]
    }
  }
]));

app.use(proxy('/api', {
  target: `http://distant-backend.com`,
  logLevel: 'debug'
}));

app.listen(8080)

HTTP requests that match one of the patterns listed in apis parameter will be mocked but others will be sent to the proxified backend.