text: 
  
  // 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);
  