Over at the JS Party podcast:
[Kend C. Dodds]: […] ask anybody who’s done regular, old CSS and they’ll tell you that “I don’t know if it’s okay for me to change this, so I’m gonna duplicate it.” And now we’ve got – at PayPal (this is not made up) we had 90% unused CSS on the project I was using, because everybody was afraid to touch the old stuff. So we just duplicated something new and called it something else. And you might just say that we’re bad at CSS, but maybe CSS was bad at us, I don’t know… [laughter]
[Emma Bostain]: Well, that’s why styled-components and CSS-in-JS was so pivotal; it was like “Oh, hey, we can actually encapsulate all of this logic inside the component that it’s touching and don’t have to worry about bleeding code anymore.” It’s so much easier to delete things, and add things, and all of those things.
[Kend C. Dodds]: Yeah, you’re precisely right. That was the problem that those things were made to solve.
I’ve heard this exact story before several times, usually from large companies. Lots of developers, typical developer turnover… nobody knows what CSS is actually used and what isn’t because that is a very hard problem.
For this reason, I’m excited that “scoped styles” are making a bit of a comeback in standards discussions.
I remember an ancient idea (that maybe even shipped in browsers for a minute?) where you’d just chuck a
<style scoped> block right in the HTML and whatever the parent was, the styles were scoped to that parent. That was so cool, I wish we could have that again.
But it seems like the newer stuff (here’s Miriam’s original proposal) has some more clever stuff that that basic concept doesn’t cover — like being able to set a lower-boundary in addition to an upper-boundary, making it possible to scope “donut-shaped” styles in the DOM (a Nicole Sullivan term). Whatever happens, shadow DOM-free scoped styles with zero tooling is huge.