Bump to v4.0.0.

keysIn.js

@@ -0,0 +1,54 @@
+import baseKeysIn from './internal/baseKeysIn';
+import indexKeys from './internal/indexKeys';
+import isIndex from './internal/isIndex';
+import isPrototype from './internal/isPrototype';
+
+/** Used for built-in method references. */
+var objectProto = Object.prototype;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
+/**
+ * Creates an array of the own and inherited enumerable property names of `object`.
+ *
+ * **Note:** Non-object values are coerced to objects.
+ *
+ * @static
+ * @memberOf _
+ * @category Object
+ * @param {Object} object The object to query.
+ * @returns {Array} Returns the array of property names.
+ * @example
+ *
+ * function Foo() {
+ *   this.a = 1;
+ *   this.b = 2;
+ * }
+ *
+ * Foo.prototype.c = 3;
+ *
+ * _.keysIn(new Foo);
+ * // => ['a', 'b', 'c'] (iteration order is not guaranteed)
+ */
+function keysIn(object) {
+  var index = -1,
+      isProto = isPrototype(object),
+      props = baseKeysIn(object),
+      propsLength = props.length,
+      indexes = indexKeys(object),
+      skipIndexes = !!indexes,
+      result = indexes || [],
+      length = result.length;
+
+  while (++index < propsLength) {
+    var key = props[index];
+    if (!(skipIndexes && (key == 'length' || isIndex(key, length))) &&
+        !(key == 'constructor' && (isProto || !hasOwnProperty.call(object, key)))) {
+      result.push(key);
+    }
+  }
+  return result;
+}
+
+export default keysIn;