JS implements GIF animation decomposition into multi-frame image upload

import SuperGif from './'

const GifDecomposer = {
  structureGifObject (gifFiles, cb) { // The file object obtained by gifFiles [0]    const gifImg = ('img');
    ('rel:animated_src', (gifFiles));
    ('rel:auto_play', '0');
    // Modified pictures must be added to the body
    (gifImg);
    // Construction example
    var rub = new SuperGif({ gif: gifImg });
    (() => {
      var img_list = [];
      for (let i=1; i <= rub.get_length(); i++) {
        // Traversing through each frame of a GIF instance
        rub.move_to(i);
        // Converting each frame of canvas into a file object
        let cur_file = (rub.get_canvas(), ('.gif', '') + `-${i}`)
        img_list.push({
          file_name: cur_file.name,
          url: (cur_file),
          file: cur_file,
        })
      }
      cb(img_list)
    });
  },
  dataURLtoFile (dataurl, filename) {
    const arr = (',');
    const mime = arr[0].match(/:(.*?);/)[1];
    const bstr = atob(arr[1]);
    var n = ;
    const u8arr = new Uint8Array(n);
    while (n--) {
      u8arr[n] = (n);
    }
    return new File([u8arr], filename, {type:mime});
  },
  convertCanvasToImage (canvas, filename) {
    return (('image/png'), filename);
  }
}

/**
 * costume upload GIF decomposer
 */
 const filesImg = function (list, storage, costumeFormat, assetType, handleCostume) {
  let proDataList = ((item, index) => {
      return new Promise(function(resolve, reject) {
        let reader = new FileReader();
        ();
         = () => {
          let data = {result: , type: , name: }
          resolve(data);
        };
         = (error) => {reject(error)};
      })
    })
  (proDataList).then(res => {
    (item => {
    // Upload    })
  }).catch(data => {(data)})
 }