fuse/src/utils/transform.ts

export const base64ToBlob = (base64Data: string) => {
  let arr = base64Data.split(",");
  let matchs = arr[0].match(/:(.*?);/);
  if (!matchs) {
    return null
  }

  let fileType = matchs[1]
  let bstr = atob(arr[1]),
    l = bstr.length,
    u8Arr = new Uint8Array(l);

  while (l--) {
    u8Arr[l] = bstr.charCodeAt(l);
  }
  return new Blob([u8Arr], {
    type: fileType,
  });
};