Selector: Use jQuery `:has` if `CSS.supports(selector(...))` non-compliant

jQuery has followed the following logic for selector handling for ages:
1. Modify the selector to adhere to scoping rules jQuery mandates.
2. Try `qSA` on the modified selector. If it succeeds, use the results.
3. If `qSA` threw an error, run the jQuery custom traversal instead.

It worked fine so far but now CSS has a concept of forgiving selector lists that
some selectors like `:is()` & `:has()` use. That means providing unrecognized
selectors as parameters to `:is()` & `:has()` no longer throws an error, it will
just return no results. That made browsers with native `:has()` support break
selectors using jQuery extensions inside, e.g. `:has(:contains("Item"))`.

Detecting support for selectors can also be done via:

```js
CSS.supports( "selector(SELECTOR_TO_BE_TESTED)" )
```
which returns a boolean. There was a recent spec change requiring this API to
always use non-forgiving parsing:
https://github.com/w3c/csswg-drafts/issues/7280#issuecomment-1143852187
However, no browsers have implemented this change so far.

To solve this, two changes are being made:
1. In browsers supports the new spec change to `CSS.supports( "selector()" )`,
   use it before trying `qSA`.
2. Otherwise, add `:has` to the buggy selectors list.

Fixes gh-5098
Closes gh-5107
Ref w3c/csswg-drafts#7676

1 files changed, 22 insertions, 0 deletions

diff --git a/src/selector.js b/src/selector.js
index bc60e61e4..871cf8682 100644
--- a/src/selector.js
+++ b/src/selector.js
@@ -9,6 +9,7 @@ import whitespace from "./var/whitespace.js";
 import rbuggyQSA from "./selector/rbuggyQSA.js";
 import rtrim from "./var/rtrim.js";
 import isIE from "./var/isIE.js";
+import support from "./selector/support.js";
 
 // The following utils are attached directly to the jQuery object.
 import "./selector/contains.js";
@@ -252,6 +253,27 @@ function find( selector, context, results, seed ) {
 				}
 
 				try {
+
+					// `qSA` may not throw for unrecognized parts using forgiving parsing:
+					// https://drafts.csswg.org/selectors/#forgiving-selector
+					// like the `:has()` pseudo-class:
+					// https://drafts.csswg.org/selectors/#relational
+					// `CSS.supports` is still expected to return `false` then:
+					// https://drafts.csswg.org/css-conditional-4/#typedef-supports-selector-fn
+					// https://drafts.csswg.org/css-conditional-4/#dfn-support-selector
+					if ( support.cssSupportsSelector &&
+
+						// eslint-disable-next-line no-undef
+						!CSS.supports( "selector(" + newSelector + ")" ) ) {
+
+						// Support: IE 11+
+						// Throw to get to the same code path as an error directly in qSA.
+						// Note: once we only support browser supporting
+						// `CSS.supports('selector(...)')`, we can most likely drop
+						// the `try-catch`. IE doesn't implement the API.
+						throw new Error();
+					}
+
 					push.apply( results,
 						newContext.querySelectorAll( newSelector )
 					);