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.