pptr-mock-server
v1.4.0
Published
Tiny library for backendless testing using Puppeteer
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pptr-mock-server
Tiny library for backendless testing using Puppeteer.
Intro
This library allows to define mock backend responses when testing web app with Puppeteer.
Internally it works purely via Puppeteer API using built-in
setRequestInterception
mechanism. It doesn't set up any servers and doesn't
modify any window APIs like XMLHttpRequest
. This provides great flexibility
and performance when handling requests, since it operates on browser internal
level.
Recommended reading: Automated UI Testing at Dock.
Installing
yarn add -D pptr-mock-server
Setting up
import puppeteer from 'puppeteer'
import mockServer from 'pptr-mock-server'
// typically your global test setup
const browser = await puppeteer.launch()
const page = await browser.newPage()
const baseAppUrl = 'http://localhost'
const mockRequest = await mockServer.init(page, {
baseAppUrl,
baseApiUrl: baseAppUrl + '/api/'
})
Basic usage
Once you have an instance of MockRequest you can pass it to your tests for registering mock responses:
const responseConfig = { body: { result: 'ok' } }
mockRequest.on('get', 'http://localhost/api/account', 200, responseConfig)
But since you provided baseApiUrl
as http://localhost/api, you can use relative endpoint name. Also you can use .get()
shorthand method instead of .on()
:
const responseConfig = { body: { result: 'ok' } }
mockRequest.get('account', 200, responseConfig)
When your app performs request to the specified resource, it will respond with the mock response provided.
Common scenarios
Handle request to relative endpoint using .on
method:
const responseConfig = { body: { result: 'ok' } }
mockRequest.on('get', 'account', 200, responseConfig)
Using shortcut .get
method and absolute url:
const responseConfig = { body: { result: 'not found' } }
mockRequest.get('https://example.com/test', 404, responseConfig)
Simulate request timeout:
mockRequest.post('search', null, { abort: 'timedout', delay: 10000 })
Mocking sequence of identical requests
Once you setup a mock request handler, every matching request will be responded with it. However it's a common scenario when you need to mock a sequence of requests, when over time the same request produces different results. Recommended way to do it is to replace previously registered mock response using new one:
const responseConfig = { body: { result: 'ok' } }
mockRequest.get('account', 200, responseConfig) // returns 200 on each request
// test deleting account logic here
// after account is deleted we want to return 401 instead of 200
mockRequest.get('account', 401) // replaces existing handler