Custom "content-encoding" without vary header

[kanongil]

I have a case where I need to do my own compression of the content, setting where I set the content-encoding header to disable the built-in processing. As it is, this also sets the vary header with an accept-encoding value during the transmit step.

Since I always set the content-encoding header, I do not want the response to vary as such. However, there is no response level option to disable this.

Note, it might not even need to be an option, as unconditionally setting the header for any response with a content-encoding header, is a bit of an overreach. Then it can be solved as a (possibly breaking) bug fix, by moving the response.vary('accept-encoding'); line after the content-encoding header check.

The relevant logic:

hapi/lib/compression.js

Lines 78 to 99 in 93378b2

	encoding(response, length) {
	const request = response.request;
	if (!request._core.settings.compression ||
	(length !== null && length < request._core.settings.compression.minBytes)) {
	return null;
	}
	const mime = request._core.mime.type(response.headers['content-type'] || 'application/octet-stream');
	if (!mime.compressible) {
	return null;
	}
	response.vary('accept-encoding');
	if (response.headers['content-encoding']) {
	return null;
	}
	return (request.info.acceptEncoding === 'identity' ? null : request.info.acceptEncoding);
	}

[kanongil]

Another option, that might work better, is for hapi to expose forced content encoding through a response object method. That way I don't need to bother with the encoding myself.

Note that I can't use a route-level option since I need to do this in response to a specific query parameter.

Edit: Such an option could also be used to signal that identity encoding should be used, thus disabling compression for the response.

[hueniverse]

How do you find yourself in all these HTTP rabbit holes...? ;-)