Support grad, rad, and turn angle units for the hue value of hsl()

[straker]

I'd like to be able to pass any of the 4 hue angle units (deg, grad, rad, and turn) to the new Color(str) constructor, but at the moment only deg works.

new Color('hsl(90deg 40% 50%)') // works
new Color('hsl(100grad 40% 50%)') // throws
new Color('hsl(1.57rad 40% 50%)')  // throws
new Color('hsl(0.25turn 40% 50%)') // throws

[Crissov]

See issue #180 and PR #181. I kinda lost interest back then.

[WilcoFiers]

@LeaVerou FYI here; This issue came from us trying to adopt Color.js into axe-core. Axe currently has its own color conversion code, but with new color spaces & syntax available in CSS 4 we needed something a little more robust. Time permitting, we'll try to contribute to help address issues.

This isn't going to increase the Color.js weekly installs number on NPM. Axe-core embeds its dependencies, but it'll be there. I'm curious if there are any considerations on using Color.js in axe-core?

You can see the PR for adding Color.js into axe-core here if you're curious: dequelabs/axe-core#4020

[LeaVerou]

We're happy to merge a PR to support other angle units.