[Draft][No ticket] New linter rule to prevent leaky selectors

[futa-ikeda]

• Ticket: [NA]
• Feature flag: n/a

To reviewers

• To try this new linter rule out locally, I went through and deleted all of the scss files in the repo and just created one scss file

cd app
find . -name "*.scss" -type f -delete
cd ../lib
find . -name "*.scss" -type f -delete

Some helpful docs https://postcss.org/api/#atrule-nodes

To do

• [ ] Finish this list of scenarios to test
• [ ] Should raise a stink for bare element selectors (e.g. h3, li)
• [ ] Should raise a stink for bare global selectors (e.g. :global(.class), :global(#id)
• [ ] Should raise a stink for bare multiple element selectors (e.g. div h3, div > h3, div,\nh3)

Purpose

• Add some custom linting to prevent any leaky css selectors

Summary of Changes

• Add new ember-osf-web-stylelint.js to house new rule
• Update .stylelintrc to use custom plugin

Screenshot(s)

• When introducing a new CSS rule that may have unintended side-effects

Side Effects

• Will need to sprinkle in a lot of // stylelint-disable statements to relevant css files

QA Notes

• No functional changes

[futa-ikeda]

Looking pretty cool so far. One thought is just in file naming. It looks like from the exports we'd only have one rule per js file. In that case, would it make more sense to have an ember-osf-web-stylelint directory and have this file be no-unlocalized-selectors.js?

Ahh, yea, that's a good call. I named it when I was assuming I could pack as many rules into that file as I wanted, but I think you're right.