use file-saver to open file

download-open-file.js

import { saveAs } from 'file-saver'
 
interface FileDownloadResponse<T> {
    body: T | null;
    contentDisposition: string;
    contentType: string;
}

  private getFileNameFromContentDisposition(res: FileDownloadResponse<Blob>) {
      const { contentDisposition } = res;
      const matches = /filename=([^;]+)/gi.exec(contentDisposition);
      const tempFilename = ((matches && matches[1]) || 'untitled').trim();
      const filename = tempFilename.replace(/["]/g, '');
      return filename;
  }

  openFile(response: FileDownloadResponse<Blob>) {
     if (response && response.body) {
         const { contentType } = response;
         const filename = this.getFileNameFromContentDisposition(response);
         saveAs(new Blob([response.body], { type: contentType }), filename);
     }
  }