These two new pseudo selectors are _action_ operators, and thus can
only be used at the end of a selector. They both take as argument
a string or regex literal.
For `:remove-class()`, when the argument matches a class name, that
class name is removed.
For `:remove-attr()`, when the argument matches an attribute name,
that attribute is removed.
These operators are meant to replace `+js(remove-attr, ...)` and
`+js(remove-class, ...)`, which from now on are candidate for
deprecation in some future.
Once the next stable release is widespread, filter authors must use
these two new operators instead of their `+js()` counterparts.
Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/2329
The supported syntax is exactly as per AdGuard's documentation:
- https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#extended-css-matches-attr
Though recommended, the quotes are not mandatory in uBO if
the argument does not cause the parser to fail and if there
are no ambiguities.
Additionally, improved the code to better unquote pseudo-operator
arguments, and to bring it closer to how AdGuard does it as per
documentation. When using quotes, `"` and `\` should be escaped
to preserve these characters in the unquoted version of the
argument.
Additionally, it is now possible to have `:has-text()` match the
empty string by just quoting the empty string:
...##foo:has-text("")
Related feedback:
- https://www.reddit.com/r/uBlockOrigin/comments/yzw5pt/
Some CSS4-based selectors are not supported in older browser versions
and this may cause cosmetic filtering to be wholly broken as a result.
The commit here is to isolate generic cosmetic filters from specific
ones in stylesheets such that unsupported CSS4 selectors in generic
cosmetic filters do not cause wholly breakage of cosmetic filtering
on all sites.
