Properties required for Firefox

[Zefling]

I've noticed a simplification of the tests in BowserScore that doesn't seem to work in Firefox. Firefox requires predefined properties, which Chromium seems to ignore. Who is correct?

In the old test, we had:

	'@counter-style example/prefix': {
			links: {
				tr: '#counter-style-prefix',
				dev: '#counter-style-prefix',
			},
			required: {
				'*': {
					descriptor: 'system: alphabetic; symbols: A B C D; additive-symbols: 1000 M, 500 C',
				},
			},
			tests: ['»', 'url(https://lea.verou.me/mark.svg)'],
		},

Comparison of results:

[Zefling]

The problem is probably the same with Webkit, but Epiphany Browser crashes with css3test.com on my PC. The result is identical to that of Firefox on BowserScore.

[LeaVerou]

Nice catch! We have a way to do this with the new syntax, since another @rule requires it. @DmitrySharabin can you look into it?

[Zefling]

Originally, I was the one who set them up. I can take a look.

[DmitrySharabin]

I took a look. To fix the tests, we should add one line (line 13):

However, this is not enough. According to the code, we'll check support for the full rule (with content) and cache the result for the full rule: https://github.com/browserscore/supports/blob/01c802e3d8ac576932ef1cb47a5fb7e6782c6824/src/types/css/rule.js#L93 and https://github.com/browserscore/supports/blob/01c802e3d8ac576932ef1cb47a5fb7e6782c6824/src/types/css/rule.js#L102.

But when we check for support for every descriptor, first, we check for support for the rule itself:
https://github.com/browserscore/app/blob/cefc3aa9cdd77be0dc08c85d8c4a0a203d09f1ab/src/classes/Feature/CSSDescriptorFeature.js#L55, https://github.com/browserscore/supports/blob/01c802e3d8ac576932ef1cb47a5fb7e6782c6824/src/types/css/descriptor-value.js#L45, and https://github.com/browserscore/supports/blob/01c802e3d8ac576932ef1cb47a5fb7e6782c6824/src/types/css/descriptor.js#L23.

When we construct that rule (its code), we don't construct the full rule with content, but only the part before {}. In our case, @counter-style foo. It doesn't hit cache (because we stored the result of testing the full rule), and it's not supported by Firefox (it needs the rule with content). As a result, all descriptors fail because of the rule itself that fails.

I tried a workaround that caches the support status not only for the full rule, but for its “main’ part, which we can get via rule.replace(/{.+}/, "") (I called it bareRule). In that case, we hit the cache for all descriptors and can check for their support (with a few more minor tweaks). But I'm not sure if it's the right approach, and we simply work around our own bugs. 🤷‍♂️