pact-mock-js v2.0.0

pact-mock-js

pact-mock-js is a Node.js library that allows you to build Pact contracts by leveraging your existings mocks. It could be used with your existing mocks defined with msw or Cypress. This library provides an easy way to generate contracts that can be used for testing and verifying API interactions between consumer and provider.

Install

yarn add -D pact-mock-js

Getting started with MSW

Here is an example of how to use pact-mock-js with MSW:

import { setupServer, rest } from 'msw/node'
import { Pact } from 'pact-mock-js/msw'
import { writeFile } from 'fs'

const server = setupServer()

const pact = new Pact({
  consumer: { name: 'test-consumer' },
  provider: { name: 'rest-provider' },
  metadata: { pactSpecification: { version: '2.0.0' } },
})

beforeAll(() => {
  server.listen()
  pact.reset()
})

afterEach(() => {
  server.resetHandlers()
})

afterAll(() => {
  server.close()
  // Write the pact file wherever you want
  fs.writeFile(
    `pacts/${pact.name}.json`,
    JSON.stringify(pact.generatePactFile())
  )
})

it('get all movies', async () => {
  const mockMovies = rest.get(
    '*/movies',
    pact.toResolver({
      description: 'a request to list all movies',
      response: [
        {
          id: 1,
          name: 'Movie 1',
          year: 2008,
        },
        {
          id: 2,
          name: 'Movie 2',
          year: 2008,
        },
      ],
    })
  )

  server.use(mockMovies)

  const movies = await fetchMovies()

  expect(movies).toEqual([
    {
      id: 1,
      name: 'Movie 1',
      year: 2008,
    },
    {
      id: 2,
      name: 'Movie 2',
      year: 2008,
    },
  ])
})

You can find more example to mock

• A Rest API
• A GraphQL API

Getting started with Cypress

Here is an example of how to use pact-mock-js with Cypress:

import { Pact } from 'pact-mock-js/cypress'

const server = setupServer()

const pact = new Pact({
  consumer: { name: 'test-consumer' },
  provider: { name: 'rest-provider' },
  metadata: { pactSpecification: { version: '2.0.0' } },
})

before(() => {
  pact.reset()
})

after(() => {
  // Write the pact file wherever you want
  cy.writeFile(`pacts/${pact.name}.json`, pact.generatePactFile())
})

it('get all movies', async () => {
  // intercept and mock the movies response while record the interaction
  cy.intercept(
    'GET',
    `/*/movies`,
    pact.toHandler({
      description: 'a request to list all movies',
      response: [
        {
          id: 1,
          name: 'Movie 1',
          year: 2008,
        },
        {
          id: 2,
          name: 'Movie 2',
          year: 2008,
        },
      ],
    })
  ).as('multipleMovies')

  // open the page to test
  cy.visit('/')

  // add your assertions
  cy.wait('@multipleMovies')
    .its('response')
    .its('statusCode')
    .should('be.equal', 200)
})

You can find more example to mock

• A Rest API
• A GraphQL API

Author

👤 Ludovic Dorival

• Github: @ludorival

Show your support

Give a ⭐️ if this project helped you!

📝 License

Copyright © 2021 Ludovic Dorival. This project is BSD--3--Clause licensed.

This README was generated with ❤️ by readme-md-generator