Refactor parameterCount to optimize performance

lib/types/urlencoded.js

@@ -208,19 +208,9 @@
  */
 
 function parameterCount (body, limit) {
-  var count = 0
-  var index = 0
+  var len = body.split('&').length;
 
-  while ((index = body.indexOf('&', index)) !== -1) {
-    count++
-    index++
-
-    if (count === limit) {
-      return undefined
-    }
-  }
-
-  return count
+  return len > limit ? undefined : len - 1;
 }
 
 /**

package.json

@@ -44,7 +44,6 @@
     "lint": "eslint .",
     "test": "mocha --reporter spec --check-leaks test/",
     "test-ci": "nyc --reporter=lcovonly --reporter=text npm test",
-
     "test-cov": "nyc --reporter=html --reporter=text npm test"
   }
 }