add book.js

node_modules/lodash/internal/charsLeftIndex.js

@@ -0,0 +1,18 @@
+/**
+ * Used by `_.trim` and `_.trimLeft` to get the index of the first 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 first character not found in `chars`.
+ */
+function charsLeftIndex(string, chars) {
+  var index = -1,
+      length = string.length;
+
+  while (++index < length && chars.indexOf(string.charAt(index)) > -1) {}
+  return index;
+}
+
+module.exports = charsLeftIndex;