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

mgol · mgol · commit ff6a2e2ecc80 · 2022-09-05T17:03:12.000+02:00
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: w3c/csswg-drafts#7280 (comment) 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
diff --git 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";
@@ -251,7 +252,31 @@ function find( selector, context, results, seed ) {
 					newSelector = groups.join( "," );
 				}
 
+				// Support: Chrome 105+, Firefox 104+, Safari 15.4+
+				// Most browsers incorrectly use forgiving parsing in `CSS.supports`.
+				// TODO this should be next to `:has` workarounds.
+
 				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 )
 					);
diff --git a/src/selector/rbuggyQSA.js b/src/selector/rbuggyQSA.js
@@ -1,19 +1,38 @@
 import isIE from "../var/isIE.js";
 import whitespace from "../var/whitespace.js";
+import support from "../var/support.js";
 
-var rbuggyQSA = isIE && new RegExp(
+var rbuggyQSA = [];
 
-	// Support: IE 9 - 11+
-	// IE's :disabled selector does not pick up the children of disabled fieldsets
-	":enabled|:disabled|" +
+if ( isIE ) {
+	rbuggyQSA.push(
 
-	// Support: IE 11+
-	// IE 11 doesn't find elements on a `[name='']` query in some cases.
-	// Adding a temporary attribute to the document before the selection works
-	// around the issue.
-	"\\[" + whitespace + "*name" + whitespace + "*=" +
-		whitespace + "*(?:''|\"\")"
+		// Support: IE 9 - 11+
+		// IE's :disabled selector does not pick up the children of disabled fieldsets
+		":enabled",
+		":disabled",
 
-);
+		// Support: IE 11+
+		// IE 11 doesn't find elements on a `[name='']` query in some cases.
+		// Adding a temporary attribute to the document before the selection works
+		// around the issue.
+		"\\[" + whitespace + "*name" + whitespace + "*=" +
+			whitespace + "*(?:''|\"\")"
+	);
+}
+
+if ( !support.cssSupportsSelector ) {
+
+	// Support: Chrome 105+, Safari 15.4+
+	// `:has()` uses a forgiving selector list as an argument so our regular
+	// `try-catch` mechanism fails to catch `:has()` with arguments not supported
+	// natively like `:has(:contains("Foo"))`. Where supported & spec-compliant,
+	// we now use `CSS.supports("selector(SELECTOR_TO_BE_TESTED)")` but outside
+	// that, let's mark `:has` as buggy to always use jQuery traversal for
+	// `:has`.
+	rbuggyQSA.push( ":has" );
+}
+
+rbuggyQSA = rbuggyQSA.length && new RegExp( rbuggyQSA.join( "|" ) );
 
 export default rbuggyQSA;
diff --git a/src/selector/support.js b/src/selector/support.js
@@ -0,0 +1,24 @@
+import support from "../var/support.js";
+
+try {
+	/* eslint-disable no-undef */
+
+	// Support: Chrome 105+, Firefox 104+, Safari 15.4+
+	// Make sure forgiving mode is not used in `CSS.supports( "selector(...)" )`.
+	//
+	// `:is()` uses a forgiving selector list as an argument and is widely
+	// implemented, so it's a good one to test against.
+	support.cssSupportsSelector = CSS.supports( "selector(*)" ) &&
+
+		// `*` is needed as Safari & newer Chrome implemented something in between
+		// for `:has()` - it throws in `qSA` if it only contains an unsupported
+		// argument but multiple ones, one of which is supported, are fine.
+		// We want to play safe in case `:is` gets the same treatment.
+		!CSS.supports( "selector(:is(*,:jqfake))" );
+
+	/* eslint-enable */
+} catch ( e ) {
+	support.cssSupportsSelector = false;
+}
+
+export default support;
diff --git a/test/unit/selector.js b/test/unit/selector.js
@@ -931,13 +931,21 @@ QUnit.test( "pseudo - nth-last-of-type", function( assert ) {
 } );
 
 QUnit[ QUnit.jQuerySelectors ? "test" : "skip" ]( "pseudo - has", function( assert ) {
-	assert.expect( 3 );
+	assert.expect( 4 );
 
 	assert.t( "Basic test", "p:has(a)", [ "firstp", "ap", "en", "sap" ] );
 	assert.t( "Basic test (irrelevant whitespace)", "p:has( a )", [ "firstp", "ap", "en", "sap" ] );
 	assert.t( "Nested with overlapping candidates",
 		"#qunit-fixture div:has(div:has(div:not([id])))",
 		[ "moretests", "t2037", "fx-test-group", "fx-queue" ] );
+
+	// Support: Safari 15.4+
+	// `qSA` in Safari throws for `:has()` with only unsupported arguments
+	// but if you add a supported arg to the list, it will run and just potentially
+	// return no results. Make sure this is accounted for.
+	assert.t( "Nested with list arguments",
+		"#qunit-fixture div:has(faketag, div:has(faketag, div:not([id])))",
+		[ "moretests", "t2037", "fx-test-group", "fx-queue" ] );
 } );
 
 QUnit[ QUnit.jQuerySelectors ? "test" : "skip" ]( "pseudo - contains", function( assert ) {
diff --git a/test/unit/support.js b/test/unit/support.js
@@ -59,19 +59,24 @@ testIframe(
 		userAgent = window.navigator.userAgent,
 		expectedMap = {
 			ie_11: {
-				"reliableTrDimensions": false
+				cssSupportsSelector: false,
+				reliableTrDimensions: false
 			},
 			chrome: {
-				"reliableTrDimensions": true
+				cssSupportsSelector: false,
+				reliableTrDimensions: true
 			},
 			safari: {
-				"reliableTrDimensions": true
+				cssSupportsSelector: true,
+				reliableTrDimensions: true
 			},
 			firefox: {
-				"reliableTrDimensions": false
+				cssSupportsSelector: false,
+				reliableTrDimensions: false
 			},
 			ios: {
-				"reliableTrDimensions": true
+				cssSupportsSelector: true,
+				reliableTrDimensions: true
 			}
 		};
 
