cli 3: runner.js

const Nightwatch = require('nightwatch');
const browserstack = require('browserstack-local');
const spawn = require('cross-spawn');
const browserstackConfig = require('./browserstack.config');

if (process.env.RUNNER === browserstackConfig.RUNNER) {
  let bs_local;

  try {
    process.mainModule.filename = './node_modules/.bin/nightwatch';

    // Code to start browserstack local before start of test
    console.log('Connecting local');
    Nightwatch.bs_local = bs_local = new browserstack.Local();
    bs_local.start({ key: browserstackConfig.KEY, forceLocal: 'true' }, (error) => {
      if (error) throw error;

      console.log('Connected. Now testing...');
      Nightwatch.cli((argv) => {
        argv.config = 'nightwatch.config.js';
        Nightwatch.CliRunner(argv)
          .setup(null, () => {
          // Code to stop browserstack local after end of parallel test
            bs_local.stop(() => {});
          })
          .runTests(() => {
            // Code to stop browserstack local after end of single test
            bs_local.stop(() => {});
          });
      });
    });
  } catch (ex) {
    console.log('There was an error while starting the test runner:\n\n');
    process.stderr.write(`${ex.stack}\n`);
    process.exit(2);
  }
} else {
  const options = process.argv.slice(2);

  options.unshift('test:e2e');
  spawn('./node_modules/.bin/vue-cli-service', options, { stdio: 'inherit' });
}