lodash

Index: package/_trimmedEndIndex.js
===================================================================
--- package/_trimmedEndIndex.js
+++ package/_trimmedEndIndex.js
@@ -0,0 +1,19 @@
+/** Used to match a single whitespace character. */
+var reWhitespace = /\s/;
+
+/**
+ * Used by `_.trim` and `_.trimEnd` to get the index of the last non-whitespace
+ * character of `string`.
+ *
+ * @private
+ * @param {string} string The string to inspect.
+ * @returns {number} Returns the index of the last non-whitespace character.
+ */
+function trimmedEndIndex(string) {
+  var index = string.length;
+
+  while (index-- && reWhitespace.test(string.charAt(index))) {}
+  return index;
+}
+
+module.exports = trimmedEndIndex;