code: function parseFiles(filepaths) {
    console.log('Checking Syntax');
  
    return Promise.all(filepaths.map(filepath => {
      if (isJS(filepath) && !isTest(filepath)) {
        return exec('babel', [
          '--optional', 'runtime',
          '--out-file', '/dev/null',
          srcPath(filepath)
        ]);
      }
    }));
  }
docs: Checking steps