Angular API File Download

app-utility.service.ts

import { saveAs } from 'file-saver';

...

downloadFile(){
  return this.serviceWrapper(
    'POST',
    this.getAPI('file_download'),
    (response: any) => {
      let file_name = "dummy_file.pdf";
      saveAs(response, file_name);
      return {'data': {'message': 'download success'}};
    },
    {
      body: {
        'dummy': 'data'
      },
      responseType: "blob"
    }
  );
}