is it possible to "yield" a async process in node v10.x?

i'm using the request module to fetch image from website and pipe it into local file, the code is like:

url = http:/xxx.com/x.jpg;
if(url){
  request(url).pipe(localFilePath);
}

if(xxx){
  // save the localFilePath to db;
  redirect('/index');
}

// The question is the filePath is needed in the index page, so if the file has not downloaded yet, then it can not show the file on index page.

i tried.

request(url).pipe(...).on('end',function(){
  ....
}); 

but it seems does't work..

so, i wonder how to do like :

yield xxxxx in node v0.11.x to pause the process until the file is already downloaded completely?

thanks