NightMare でスクリーンショットを撮る時にディレクトリを作成する

var paths = require('path');
var makeDir = require('make-dir');

// 中略

exports.screenshot = function (path, clip, done) {
  debug('.screenshot()');
  if (typeof path === 'function') {
    done = path;
    clip = undefined;
    path = undefined;
  } else if (typeof clip === 'function') {
    done = clip;
    clip = (typeof path === 'string') ? undefined : path;
    path = (typeof path === 'string') ? path : undefined;
  }
  this.child.call('screenshot', path, clip, function (error, img) {
    var buf = new Buffer(img);

　　 // debug('.screenshot() captured with length %s', buf.length);
    // path ? fs.writeFile(path, buf, done) : done(null, buf);
    // ↓
    makeDir(paths.dirname(path)).then(res => {
      console.log(res);

      debug('.screenshot() captured with length %s', buf.length);
      path ? fs.writeFile(path, buf, done) : done(null, buf);
    });

  });
};