fix(isSkipLink): cache first page link (#1525)

dequelabs · May 1, 2019 · 6a1bcba · 6a1bcba
1 parent 9cea13d
commit 6a1bcba
Showing 1 changed file with 15 additions and 7 deletions.
diff --git a/lib/commons/dom/is-skip-link.js b/lib/commons/dom/is-skip-link.js
@@ -16,13 +16,21 @@ dom.isSkipLink = function(element) {
 		return false;
 	}
 
-	// define a skip link as any anchor element whose href starts with `#...`
-	// and which precedes the first anchor element whose href doesn't start
-	// with  `#...` (that is, a link to a page)
-	const firstPageLink = axe.utils.querySelectorAll(
-		axe._tree,
-		'a:not([href^="#"]):not([href^="/#"]):not([href^="javascript"])'
-	)[0];
+	let firstPageLink;
+	if (typeof axe._cache.firstPageLink !== 'undefined') {
+		firstPageLink = axe._cache.firstPageLink;
+	} else {
+		// define a skip link as any anchor element whose href starts with `#...`
+		// and which precedes the first anchor element whose href doesn't start
+		// with  `#...` (that is, a link to a page)
+		firstPageLink = axe.utils.querySelectorAll(
+			axe._tree,
+			'a:not([href^="#"]):not([href^="/#"]):not([href^="javascript"])'
+		)[0];
+
+		// null will signify no first page link
+		axe._cache.firstPageLink = firstPageLink || null;
+	}
 
 	// if there are no page links then all all links will need to be
 	// considered as skip links