src/lib/base64ToFile.ts

export function base64ToFile(dataurl: string, filename: string) {
  var arr = dataurl.split(','),
      mime = arr[0].match(/:(.*?);/)?.[1],
      bstr = atob(arr[arr.length - 1]), 
      n = bstr.length, 
      u8arr = new Uint8Array(n);
  while(n--){
      u8arr[n] = bstr.charCodeAt(n);
  }
  return new File([u8arr], filename, {type:mime});
}