How to use the @wdio/cli.default function in @wdio/cli

// force shutdown after 15s timeout
    setTimeout(() => {
      debug(`Could not close server in time, forcefully shutting down`);
      process.exit();
    }, (15e3));
  };

  debug(`es-dev-server running at port ${PORT}...`);

  [
    'SIGTERM', // kill
    'SIGINT', // Ctrl or Cmd + C
  ].forEach(n => process.on(n, gracefulShutdown));

  const wdio = new Launcher(readArg('--config-file'));

  await wdio.run();

  debug(`Completed. Closing server...`);

  gracefulShutdown();
}

function runE2eTests(configFilePath, runSelenium) {
  const wdio = new Launcher(configFilePath, {})
  function runWdio() {
    wdio.run().then(
      function(code) {
        process.stdin.pause()
        process.nextTick(() => process.exit(code))
      },
      function(error) {
        console.error('Launcher failed to start the test', error)
        process.stdin.pause()
        process.nextTick(() => process.exit())
      }
    )
  }
  if (runSelenium) {
    startSelenium(runWdio)
  } else {

exports.run = async function() {
  const Launcher = require('@wdio/cli').default;
  const wdio = new Launcher(
    __dirname + '/../../test/functional/wdio.conf.js', {});

  return await wdio.run();
};