Save file to disk from blob or Response

save-file-from-blob.ts

export async function saveFileFromResponse(response: Response, filename?: string) {
  filename = filename || getResponseAttachmentFileName(response) || 'file';
  const data = await response.blob();
  const type = data.type || 'application/octet-stream';

  saveBlobAsFile(data, filename, type)
}

export function saveBlobAsFile(blob: Blob, fileName: string, mimeType: string){
  if (typeof navigator.msSaveBlob === 'function') {
    navigator.msSaveBlob(blob, fileName);
    return;
  }

  const file = new File([blob], fileName, {type: mimeType});
  const exportUrl = URL.createObjectURL(file);
  window.location.assign(exportUrl);

  setTimeout(() => {
    // For Firefox it is necessary to delay revoking the ObjectURL
    URL.revokeObjectURL(exportUrl);
  }, 100);
}

export function getResponseAttachmentFileName(response: Response): string {
  return response.headers
    ?.get('content-disposition')
    ?.split(';')
    ?.map(str => str.trim())
    ?.find(str => str.indexOf('filename=') === 0)
    ?.split('filename=')[1] || '';
}