Save a binary file using REQUEST module in Node the right way

I was trying to save some PDF from an output of a request, and I always got a corrupted file.

Initially I found that I saved my file as UTF-8 while it was ascii (took almost double), so I added the ASCII encoding to the file fs,fileWrite command, this helped a bit but still corrupted.

Eventually I read some more about the request module and identified that i was missing the "encoding: 'binary'" in the options!

This is the final code:

	SaveThePDF(url, filename) {
	const writeFile = denodeify(fs.writeFile);
	const requestPromised = denodeify(request.defaults({
	'gzip': true,
	headers: {
	'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.101 Safari/537.36',
	'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,\/;q=0.8',
	}
	}), function(err, httpResponse, body) {
	// Convert 3 paramters to 2
	return [err, {httpResponse: httpResponse, body: body}];
	});

	return requestPromised({
	url: url,
	method: 'post',
	encoding: 'binary'
	}).then ( (response) => {
	return writeFile(filename, response.body, 'ascii');
	});
	}