--- /dev/null
+var isArguments = require('../lang/isArguments'),
+ isArray = require('../lang/isArray'),
+ isIndex = require('./isIndex'),
+ isLength = require('./isLength'),
+ keysIn = require('../object/keysIn');
+
+/** Used for native method references. */
+var objectProto = Object.prototype;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
+/**
+ * A fallback implementation of `Object.keys` which creates an array of the
+ * own enumerable property names of `object`.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @returns {Array} Returns the array of property names.
+ */
+function shimKeys(object) {
+ var props = keysIn(object),
+ propsLength = props.length,
+ length = propsLength && object.length;
+
+ var allowIndexes = !!length && isLength(length) &&
+ (isArray(object) || isArguments(object));
+
+ var index = -1,
+ result = [];
+
+ while (++index < propsLength) {
+ var key = props[index];
+ if ((allowIndexes && isIndex(key, length)) || hasOwnProperty.call(object, key)) {
+ result.push(key);
+ }
+ }
+ return result;
+}
+
+module.exports = shimKeys;