Enable hot reloading of imported stylesheets

[andrewcoelho]

Initializes postcss as a function with the wp argument
passed in. This allows to use the 'addDependencyTo' option
of postcss-import plugin so that hot reloading will work
properly with imported stylesheets.

[KyleAMathews]

What exactly does this option do? It's only for enabling hot reloading? I just want to make sure I understand the implications of the change.

[andrewcoelho]

It is only for enabling hot reloading.

When using css modules, this isn't necessary as each stylesheet is required directly.

However, when using a more traditional global stylesheet approach, where there is only one root level require which contains @import statements of other stylesheet partials, the only thing hot reloaded will be the root level stylesheet.

By adding the dependency to webpack in the postcss-import plugin, it allows stylesheet partials which are @imported to be hot reloaded as well.

https://github.com/postcss/postcss-import/blob/master/README.md#adddependencyto

[KyleAMathews]

Thanks for the explanation! Sounds like a winner of a change.

[jlengstorf]

Hiya @andrewcoelho! 👋

This is definitely late, but on behalf of the entire Gatsby community, I wanted to say thank you for being here.

Gatsby is built by awesome people like you. Let us say “thanks” in two ways:

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