add book.js

node_modules/lodash/internal/charsRightIndex.js

@@ -0,0 +1,17 @@
+/**
+ * Used by `_.trim` and `_.trimRight` to get the index of the last character
+ * of `string` that is not found in `chars`.
+ *
+ * @private
+ * @param {string} string The string to inspect.
+ * @param {string} chars The characters to find.
+ * @returns {number} Returns the index of the last character not found in `chars`.
+ */
+function charsRightIndex(string, chars) {
+  var index = string.length;
+
+  while (index-- && chars.indexOf(string.charAt(index)) > -1) {}
+  return index;
+}
+
+module.exports = charsRightIndex;