add book.js

node_modules/lodash/object/functions.js

@@ -0,0 +1,23 @@
+var baseFunctions = require('../internal/baseFunctions'),
+    keysIn = require('./keysIn');
+
+/**
+ * Creates an array of function property names from all enumerable properties,
+ * own and inherited, of `object`.
+ *
+ * @static
+ * @memberOf _
+ * @alias methods
+ * @category Object
+ * @param {Object} object The object to inspect.
+ * @returns {Array} Returns the new array of property names.
+ * @example
+ *
+ * _.functions(_);
+ * // => ['after', 'ary', 'assign', ...]
+ */
+function functions(object) {
+  return baseFunctions(object, keysIn(object));
+}
+
+module.exports = functions;