css-color-parser + postcss-color-mix-function

[romainmenke]

• css-color-parser package
• postcss-color-mix-function plugin
• refactored postcss-hwb-function plugin
• refactored postcss-lab-function plugin
• refactored postcss-oklab-function plugin
• refactored postcss-color-function plugin
• removed some unused functions from color-helpers package
• better checks for lower case matches in some functions ¹
• better fallbacks for in/out of gamut colors with smaller overal output as a result

Things I skipped/didn't change :

• postcss-color-functional-notation, technically css-color-parser can help here, but this plugin is more a syntax desugaring and not really a color transform
• relative color syntax because it just doesn't seem ready yet for implementations

---

I think this is ready to be shipped as a standalone plugin.

There are a few minor open issues I still want to wait on before adding to postcss-preset-env. It seems that browsers have incorrect implementations for a wide range of cases and I don't want to add to postcss-preset-env before confirmation that our implementation is correct.

---

Footnotes

1. 'blacK'.toLowerCase() === 'black' but K isn't actually an upper case k. It is a different unicode char that is equivelant to an upper case k in certain locales. ↩

[Antonio-Laguna]

This looks great!

I had to review this on the editor since this is a huge change and makes the browser suffer a lot.

This is so great to have it finally there! I'm really looking forward to this getting merged and out in the wild.

Thanks for all the work and the changes around the tooling and the other color functions!

[romainmenke]

Thank you for working through this massive review 🙇
Yeah will be awesome to get this out there!