metamask-extension/test/helper.js

import Ganache from 'ganache-core'
import nock from 'nock'
import Enzyme from 'enzyme'
import Adapter from 'enzyme-adapter-react-16'
import log from 'loglevel'

nock.disableNetConnect()
nock.enableNetConnect('localhost')

// catch rejections that are still unhandled when tests exit
const unhandledRejections = new Map()
process.on('unhandledRejection', (reason, promise) => {
  console.log('Unhandled rejection:', reason)
  unhandledRejections.set(promise, reason)
})
process.on('rejectionHandled', (promise) => {
  console.log(`handled: ${unhandledRejections.get(promise)}`)
  unhandledRejections.delete(promise)
})

process.on('exit', () => {
  if (unhandledRejections.size > 0) {
    console.error(`Found ${unhandledRejections.size} unhandled rejections:`)
    for (const reason of unhandledRejections.values()) {
      console.error('Unhandled rejection: ', reason)
    }
    process.exit(1)
  }
})

Enzyme.configure({ adapter: new Adapter() })

// ganache server
const server = Ganache.server()
server.listen(8545)

server.on('error', console.error)
server.on('clientError', console.error)

log.setDefaultLevel(5)
global.log = log

//
// polyfills
//

// dom
const { JSDOM } = require('jsdom')

const jsdom = new JSDOM()
global.window = jsdom.window

// required by `trezor-connect/node_modules/whatwg-fetch`
global.self = window
// required by `dom-helpers` and various other libraries
global.document = window.document
// required by `react-tippy`
global.navigator = window.navigator
global.Element = window.Element
// required by `react-popper`
global.HTMLElement = window.HTMLElement

// required by any components anchored on `popover-content`
const popoverContent = window.document.createElement('div')
popoverContent.setAttribute('id', 'popover-content')
window.document.body.appendChild(popoverContent)

// delete AbortController added by jsdom so it can be polyfilled correctly below
delete window.AbortController

// fetch
const fetch = require('node-fetch')

const { Headers, Request, Response } = fetch
Object.assign(window, { fetch, Headers, Request, Response })

require('abortcontroller-polyfill/dist/polyfill-patch-fetch')

// localStorage
window.localStorage = {}

// override metamask-logo
window.requestAnimationFrame = () => {}

// crypto.getRandomValues
if (!window.crypto) {
  window.crypto = {}
}
if (!window.crypto.getRandomValues) {
  window.crypto.getRandomValues = require('polyfill-crypto.getrandomvalues')
}