Add support for bold and normal keyword aliases in scale/font-weights

[C0ZEN]

What is the problem you're trying to solve?

The font-weights rules only cover numbers, and I prefer to use aliases when possible, but not EVERY alias.
This is not helping https://github.com/signal-noise/stylelint-scales/blob/master/lib/rules/font-weights/README.md.
And https://stylelint.io/user-guide/rules/list/font-weight-notation/ is not helping either.

What solution would you like to see?

Improve the https://github.com/signal-noise/stylelint-scales/blob/master/lib/rules/font-weights/README.md to also allow some aliases.

[jeddy3]

Thanks for the request and for using the template.

The rule intentionally only supports numerics font weights because they play well with variable fonts and we can do a naive find of the font-weight within the font shorthand:

https://github.com/signal-noise/stylelint-scales/blob/84d1d5b123a785b8642fe76f39ee940032c9090e/lib/rules/font-weights/index.js#L79-L85

However, a pull request is welcome to add this enhancement i.e. 400 and 700 are aliased as "normal" and "bold" behind the scenes. It'll involve reworking the findFontWeight function to find these nodes (taking into account that the font style can also be normal, e.g. font: normal normal 1em sans-serif;).

The rule would continue to autofix to the closest numeric values as people can use Stylelint's font-weight-notation to enforce keywords.

[C0ZEN]

I am willing to give it a try, when I come back from my holidays ;)

[jeddy3]

That'd be fantastic. You're welcome to open an early work-in-progress pull request as I can help you.

The rule will still expect an array of numbers, but 400 and 700 are aliased behind the scenes.

For example, given:

{
  "plugins": ["@signal-noise/stylelint-scales"],
  "rules": {
    "scales/font-weights": [400, 600],
  }
}

The following are both valid:

a { font-weight: 400; }

a { font-weight: normal; }

The following is invalid:

a { font-weight: 300; }

And will be corrected to:

a { font-weight: 400; }

(Which Stylelint's font-weight-notation rule, if using the "named-where-possible" option will say needs to be (add can be made to autofix: stylelint/stylelint#3158) the keyword equivalent).

Enjoy your holidays!