Package: apache2 Version: 2.4.25 The default deflate.conf file provided in the Debian package for apache2 instructs the server to consider compressing responses for application/javascript. [1]
This MIME type is declared as canonical for ".js" by RFC 4329, [2] and is also associated with ".js" in the default mime.types file. This means for static JS files served from disk, Apache compresses them out-of-the-box. However, out in the wild, the text/javascript MIME type is quite common, if not more common, [3] than application/javascript. As such, when Apache proxies responses from CGI applications or from other external services, it often ends up not compressing JavaScript responses. This is currently known to affect MediaWiki, WordPress, and likely other popular web applications as well. [4][5] It can be non-trivial for an upstream like MediaWiki to change this as these MIME types may be deeply embedded in stable APIs and data structures. For example, it's database schema and its `ctype` HTTP query parameter both require `text/javascript`. RFC 4329 defines "equivalent processing requirements for text/javascript, … and application/javascript". As such, I think Apache2 should consider both of these for compression by default. This has the potential to have a big impact on the web. As an example, there seem to be lots of public MediaWiki sites out there who use Debian Linux (or downstreams like Ubuntu), and have mod_deflate enabled with the default compression for text/html and text/css, but have apparently not realised the lack of JS compression and/or were unable to configure it. [6] I am new to Debian and its bug tracker and would be interested in submitting a patch for this if the request is accepted. -- Timo Tijhof Principal Engineer, Performance Team, Wikimedia Foundation. [1] Original patch: https://salsa.debian.org/apache-team/apache2/-/commit/4d93abc8899873ff27080f9261093a02e47320e4 [2] RFC 4329: https://tools.ietf.org/html/rfc4329 [3] text/javascript might become the canonical instead: https://datatracker.ietf.org/doc/draft-ietf-dispatch-javascript-mjs/ [4] WordPress: https://github.com/WordPress/WordPress/blob/5.4.1/wp-includes/SimplePie/Misc.php#L2130 [5] MediaWiki: https://gerrit.wikimedia.org/g/mediawiki/core/+/1.34.1/includes/resourceloader/ResourceLoader.php#892 [6] StackOverflow: https://duckduckgo.com/?q=stackoverflow+ "text%2Fjavascript"+"apache"+"deflate"
