fix: refactor based on comments/ review

lib/core/constants.js

@@ -32,7 +32,7 @@
 		resultGroups: [],
 		resultGroupMap: {},
 		impact: Object.freeze(['minor', 'moderate', 'serious', 'critical']),
-		preloadAssets: Object.freeze(['cssom']),
+		preloadAssets: Object.freeze(['cssom']), // overtime this array will grow with other preload asset types, this constant is to verify if a requested preload type by the user via the configuration is supported by axe.
 		preloadAssetsTimeout: 10000
 	};
 

lib/core/utils/preload.js

@@ -27,7 +27,7 @@ function shouldPreload(options) {
 		return false;
 	}
 
-	if (typeof options.preload === typeof true) {
+	if (typeof options.preload === 'boolean') {
 		return options.preload;
 	}
 
@@ -63,16 +63,9 @@ function getPreloadConfig(options) {
 		);
 	}
 
-	// check if assets are valid items
-	const areRequestedAssetsValid = options.preload.assets.reduce(
-		(out, asset) => {
-			const a = asset.toLowerCase();
-			if (!axe.constants.preloadAssets.includes(a)) {
-				out = false;
-			}
-			return out;
-		},
-		true
+	// check if requested assets to preload are valid items
+	const areRequestedAssetsValid = options.preload.assets.every(a =>
+		axe.constants.preloadAssets.includes(a.toLowerCase())
 	);
 
 	if (!areRequestedAssetsValid) {
@@ -82,14 +75,11 @@ function getPreloadConfig(options) {
 		);
 	}
 
-	out.assets = options.preload.assets.reduce((out, asset) => {
-		const a = asset.toLowerCase();
-		// unique assets to load, in case user had requested same asset type many times.
-		if (!out.includes(a)) {
-			out.push(a);
-		}
-		return out;
-	}, []);
+	// unique assets to load, in case user had requested same asset type many times.
+	out.assets = axe.utils.uniqueArray(
+		options.preload.assets.map(a => a.toLowerCase()),
+		[]
+	);
 
 	if (
 		options.preload.timeout &&