add stripQuery method and strip the query from the extension

Author: mathieudutour

lib/util/url.js

@@ -69,11 +69,25 @@ exports.getProtocol = function getProtocol (path) {
 exports.getExtension = function getExtension (path) {
   let lastDot = path.lastIndexOf(".");
   if (lastDot >= 0) {
-    return path.substr(lastDot).toLowerCase();
+    return url.stripQuery(path.substr(lastDot).toLowerCase());
   }
   return "";
 };
 
+/**
+ * Removes the query, if any, from the given path.
+ *
+ * @param   {string} path
+ * @returns {string}
+ */
+exports.stripQuery = function stripQuery (path) {
+  let queryIndex = path.indexOf("?");
+  if (queryIndex >= 0) {
+    path = path.substr(0, queryIndex);
+  }
+  return path;
+};
+
 /**
  * Returns the hash (URL fragment), of the given path.
  * If there is no hash, then the root hash ("#") is returned.