text: // @flow
  import chalk from 'chalk';
  import detectPort from 'detect-port';
  
  (function CheckPortInUse() {
      const port: string = process.env.PORT || '1212';
  
      detectPort(port, (err: ?Error, availablePort: number) => {
          if (port !== String(availablePort)) {
              throw new Error(
                  chalk.whiteBright.bgRed.bold(
                      `Port "${port}" on "localhost" is already in use. Please use another port. ex: PORT=4343 yarn dev`
                  )
              );
          } else {
              process.exit(0);
          }
      });
  })();
  