fix: correct brotli options format

[patrickhulce]

3d205cd didn't actually fix the default compression issue described in #121 because the zlib format expects quality to be inside an option called params

Example Test Sever

const Koa = require('koa')
const {Stream} = require('stream')
const app = (module.exports = new Koa())
const compress = require('koa-compress')

app.use(async (ctx, next) => {
  await next()

  if (ctx.body instanceof Stream) {
    console.time('request')
    ctx.body.on('end', () => console.timeEnd('request'))
  }
})

app.use(compress())

app.use(async function(ctx) {
  ctx.compress = true
  ctx.body = require('crypto').randomBytes(10_000_000)
})

if (!module.parent) app.listen(3000, () => console.log('Server is up!'))

Before

$ node server &
Server is up!
$ curl http://localhost:3000 -H 'Accept-Encoding: br' > /dev/null
request: 8.398s
request: 8.354s

After

$ node server &
Server is up!
$ curl http://localhost:3000 -H 'Accept-Encoding: br' > /dev/null
request: 90.855ms
request: 71.504ms

[codecov]

Codecov Report

Merging #165 (fc8fca0) into master (5e04339) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #165   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            2         2           
  Lines           88        88           
  Branches        32        32           
=========================================
  Hits            88        88           

Impacted Files	Coverage Δ
lib/encodings.js	100.00% <ø> (ø)

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[joseph-galindo]

With this change,

compress/lib/index.js

Lines 41 to 42 in fc8fca0

	...Encodings.encodingMethodDefaultOptions[encoding],
	...(options[encoding] || {})

may need to change too.

---

As the PR is now, options['br'] will shallow merge, so if a consumer provides

koaCompress({
  br: {
    params: {
      [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT
    },
  },
});

I think the final object sent to zlib.createBrotliCompress ends up being

{
  params: {
    [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,
    // the koa-compress default of [zlib.constants.BROTLI_PARAM_QUALITY]: 4 is no longer passed in
  },
}

It can go either way but users might expect the brotli options to deep merge here

[patrickhulce]

I think the final object sent to zlib.createBrotliCompress ends up being

Correct.

users might expect the brotli options to deep merge here

True, I'll happily defer to maintainers here on what the koa community expects.

[patrickhulce]

@jonathanong friendly ping on this :)

[titanism]

We should prob also set [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,

[thynson]

When there'll be a new release ship this fix?