file upload

JavaScript
/**

async (e: Event) => {
      const chunkSize = 2 * 1024 * 1024;
      const target = e.target as HTMLInputElement;
      const targetFile = target.files![0];
      const { type, name, size } = targetFile;
      checkType(type);
      let [index, start] = [0, 0];
      while (start < size) {
        let blob = null;
        if (start + chunkSize < size) {
          blob = targetFile.slice(start, size);
        } else {
          blob = targetFile.slice(start, start + chunkSize);
        }
        start += chunkSize;
        const blobFile = new File([blob], name);
        const formData = new FormData();
        formData.append("file", blobFile);
        formData.append("index", index + "");
        await request.upload("/api/upload", formData);
        index++;
        state.percent = (start / size) * 100;
      }
 */