How to use image-type

/**
  * Validate image
  *
  * @param path
  * @returns Error|true
  */
 validateImage(path) {
  let buffer = readChunk.sync(path, 0, 12);
  let type = imageType(buffer);

  return new Promise((resolve, reject) => {
   if (this.validExtensions.indexOf(type.ext) === -1) {
    return reject(new Error(this.errors.url_image_invalid));
   }

   resolve(type.ext);
  });
 }

function loadBinary(image, base64Url) {
 const type = imageType(image);
 if (type) {
  switch (type.mime) {
   case 'image/png':
    return loadPNG(image);
   case 'image/jpeg':
    return loadJPEG(image);
   case 'image/tiff':
    return loadTIFF(image);
   default:
    return loadGeneric(getBase64(type.mime));
  }
 }
 return loadGeneric(getBase64('application/octet-stream'));
 function getBase64(type) {
  if (base64Url) {
   return base64Url;
  } else {
   return toBase64URL(image, type);
  }
 }
}