Don't read internal files from postcss

[RyanZim]

Currently autoprefixer does things like const list = require('postcss/lib/list');
instead of const list = require('postcss').list;

This makes bundling autoprefixer, postcss, and other postcss plugins with bundle splitting very difficult to do without duplicating parts of postcss.

Additionally, it could be argued this is breaking point 2.4 the plugin guidelines, since the paths aren't documented in the API docs. This prevents postcss from changing its internal directory structure.

Would you be open to changing this?

[ai]

Why it makes it difficult to split bundle?

Anyway we have postcss.list = require ("postcss/list")

[RyanZim]

Why it makes it difficult to split bundle?

Not sure about all bundlers, but some (like browserify) treat each file as its own module. So if you specify that postcss should be split to a different bundle file, postcss/lib/list won't be split out. The end result is that the list code is included in both bundle files.

Anyway we have postcss.list = require ("postcss/list")

Not sure I understand?

[ai]

There is no 1 postcss bundle in PostCSS npm package. I don't use Rollup or webpack during npm publish. So PostCSS will be a bunch of small files in the bundle.

Just open node_modules/postcss/.

So anyway your bundle will have separated file for postcss/list. What all be a difference if I will use postcss.list in Autoprefixer?

[RyanZim]

I know it isn't one big file. However, if you only require postcss directly, bundlers are able to figure out what you're doing and be smarter about code splitting.

i.e. if bundle A contains postcss, and bundle B contains autoprefixer, the bundler can see that autoprefixer can use postcss from bundle A. However, it doesn't know that postcss/lib/list can be obtained from postcss.list as well, so it it includes the list code in bundle B as well, when it's already included in bundle A.

[RyanZim]

TL;DR it makes my life a lot easier. Is there a specific reason we can't do const list = require('postcss').list;?

[ai]

Yeap, it is not big deal, I can replace it. Do you want to send PR?

[RyanZim]

Sure, I can do that.