Support for brotli (br) compression in compress middleware

[spaceemotion]

What is the feature you are proposing?

We're trying to modernize our app with Hono, but we'd like to use brotli compression for responses, instead of just gzip. Ssome of our calls can be a couple megabytes compressed, and the ratio between gzip and brotli is quite different.

From what I can tell, the list of supported compression algorithms is hard-coded:

hono/src/middleware/compress/index.ts

Line 9 in f8664b0

const ENCODING_TYPES = ['gzip', 'deflate'] as const

hono/src/middleware/compress/index.ts

Line 23 in f8664b0

* @param {'gzip' | 'deflate'} [options.encoding] - The compression scheme to allow for response compression. Either 'gzip' or 'deflate'. If not defined, both are allowed and will be used based on the Accept-Encoding header. 'gzip' is prioritized if this option is not provided and the client provides both in the Accept-Encoding header.

The node zlib package supports brotli, which should make it possible to implement it without an additional third party dependency.

Also, if there is a way to use the text mode for brotli for when the content is JSON or other text-only stuff would be great.

[EdamAme-x]

I think it's not bad since edge runtime etc. also supports this feature. (but, it's not supportted on service-worker as browser's features)
https://developers.cloudflare.com/workers/runtime-apis/nodejs/zlib/

[exoego]

Compress middleware relies on CompressionStream which does not support Brotli yet unfortunately.

Good news is that W3C TPAC is going to add Brotli to the standard.

whatwg/compression#34 (comment)
To summarise the discussion at TPAC 2024, we are going to add Brotli to the standard, but Chrome still won't be able to ship it for a while. It appears that Safari is ready to ship and Firefox is also positive on shipping.

[EdamAme-x]

planning to ship! Looks good.

[yusukebe]

How about Zstandard? 😉

[spaceemotion]

Brotli coming to the standards is good news indeed! I am guessing our only workaround for now is to clone the middleware, replace the bits and pieces to fit our node runtime, and wait until we can use the 'native' way?

[vuolter]

In the meantime I made my own plugin, with blackjack and hookers! 🤖

https://github.com/vuolter/hono-compress