Download files in cypress <6.0

download.js

const path = require('path')
const { promisify } = require('util')
const CDP = require('chrome-remote-interface')
const debug = require('debug')('cypress:server:protocol')
const rimraf = promisify(require('rimraf'))

let port = 0
let client = null

module.exports = (on, config) => {
  const downloadPath = path.resolve(config.projectRoot, './downloads')

  function ensureRdpPort (args) {
    const existing = args.find((arg) =>
      arg.startsWith('--remote-debugging-port')
    )

    if (existing) {
      return Number(existing.split('=')[1])
    }

    const port = 40000 + Math.round(Math.random() * 25000)

    args.push(`--remote-debugging-port=${port}`)

    return port
  }

  async function resetCRI () {
    if (client) {
      debug('resetting CRI client')
      await client.close()
      client = null
    }
  }

  async function cleanDownloads () {
    debug(`cleaning up downloads at ${downloadPath}`)

    await rimraf(downloadPath)
  }

  async function allowDownloads () {
    await resetCRI()
    await cleanDownloads()

    debug(`enabling downloads at ${downloadPath}`)

    client = client || (await CDP({ port }))

    return client.send('Browser.setDownloadBehavior', {
      behavior: 'allow',
      downloadPath
    })
  }

  on('before:browser:launch', (browser, options) => {
    if (browser.family === 'chromium') {
      debug('browser launch args or options %o', options)

      const args = Array.isArray(options)
        ? options
        : options.args

      port = ensureRdpPort(args)

      debug('ensureRdpPort %d', port)
      debug('Chrome arguments %o', args)
    }
    if (browser.family === 'firefox') {
      options.preferences['browser.download.dir'] = downloadPath
      options.preferences['browser.download.folderList'] = 2
      options.preferences['browser.helperApps.neverAsk.saveToDisk'] = 'application/pdf'
      options.preferences['browser.helperApps.alwaysAsk.force'] = 'false'
      return options
    }
  })

  return {
    resetCRI,
    allowDownloads,
    cleanDownloads
  }
}

index.js

  on('task', require('./download')(on, config))