Better class name detection for plugins (#1772)

This improves the class name regex of a few plugins to avoid false positives.

plugins/line-numbers/prism-line-numbers.js

@@ -9,7 +9,7 @@
 	 * @type {String}
 	 */
 	var PLUGIN_NAME = 'line-numbers';
-	
+
 	/**
 	 * Regular expression used for determining line breaks
 	 * @type {RegExp}
@@ -73,7 +73,7 @@
 
 		// works only for <code> wrapped inside <pre> (not inline)
 		var pre = env.element.parentNode;
-		var clsReg = /\s*\bline-numbers\b\s*/;
+		var clsReg = /(?:^|\s)line-numbers(?:\s|$)/;
 		if (
 			!pre || !/pre/i.test(pre.nodeName) ||
 			// Abort only if nor the <pre> nor the <code> have the class
@@ -123,7 +123,7 @@
 		env.plugins = env.plugins || {};
 		env.plugins.lineNumbers = true;
 	});
-	
+
 	/**
 	 * Global exports
 	 */
@@ -156,4 +156,4 @@
 		}
 	};
 
-}());
+}());

plugins/normalize-whitespace/prism-normalize-whitespace.js

@@ -148,7 +148,7 @@ Prism.hooks.add('before-sanity-check', function (env) {
 
 	// Normal mode
 	var pre = env.element.parentNode;
-	var clsReg = /\bno-whitespace-normalization\b/;
+	var clsReg = /(?:^|\s)no-whitespace-normalization(?:\s|$)/;
 	if (!env.code || !pre || pre.nodeName.toLowerCase() !== 'pre' ||
 			clsReg.test(pre.className) || clsReg.test(env.element.className))
 		return;

plugins/remove-initial-line-feed/prism-remove-initial-line-feed.js

@@ -7,7 +7,7 @@ if (typeof self === 'undefined' || !self.Prism || !self.document) {
 Prism.hooks.add('before-sanity-check', function (env) {
 	if (env.code) {
 		var pre = env.element.parentNode;
-		var clsReg = /\s*\bkeep-initial-line-feed\b\s*/;
+		var clsReg = /(?:^|\s)keep-initial-line-feed(?:\s|$)/;
 		if (
 			pre && pre.nodeName.toLowerCase() === 'pre' &&
 			// Apply only if nor the <pre> or the <code> have the class
@@ -18,4 +18,4 @@ Prism.hooks.add('before-sanity-check', function (env) {
 	}
 });
 
-}());
+}());