text: 'use strict'
  
  // Do this as the first thing so that any code reading it knows the right env.
  process.env.BABEL_ENV = 'test'
  process.env.NODE_ENV = 'test'
  process.env.PUBLIC_URL = ''
  
  // Makes the script crash on unhandled rejections instead of silently
  // ignoring them. In the future, promise rejections that are not handled will
  // terminate the Node.js process with a non-zero exit code.
  process.on('unhandledRejection', err => {
    throw err
  })
  
  // Ensure environment variables are read.
  require('../config/env')
  
  const jest = require('jest')
  const execSync = require('child_process').execSync
  let argv = process.argv.slice(2)
  
  function isInGitRepository () {
    try {
      execSync('git rev-parse --is-inside-work-tree', { stdio: 'ignore' })
      return true
    } catch (e) {
      return false
    }
  }
  
  function isInMercurialRepository () {
    try {
      execSync('hg --cwd . root', { stdio: 'ignore' })
      return true
    } catch (e) {
      return false
    }
  }
  
  // Watch unless on CI or explicitly running all tests
  if (
    !process.env.CI &&
    argv.indexOf('--watchAll') === -1
  ) {
    // https://github.com/facebook/create-react-app/issues/5210
    const hasSourceControl = isInGitRepository() || isInMercurialRepository()
    argv.push(hasSourceControl ? '--watch' : '--watchAll')
  }
  
  jest.run(argv)
  