Bump to v3.0.0.

lang/isPlainObject.js

@@ -0,0 +1,62 @@
+import isNative from './isNative';
+import shimIsPlainObject from '../internal/shimIsPlainObject';
+
+/** `Object#toString` result references. */
+var objectTag = '[object Object]';
+
+/** Used for native method references. */
+var objectProto = Object.prototype;
+
+/**
+ * Used to resolve the `toStringTag` of values.
+ * See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.prototype.tostring)
+ * for more details.
+ */
+var objToString = objectProto.toString;
+
+/** Native method references. */
+var getPrototypeOf = isNative(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf;
+
+/**
+ * Checks if `value` is a plain object, that is, an object created by the
+ * `Object` constructor or one with a `[[Prototype]]` of `null`.
+ *
+ * **Note:** This method assumes objects created by the `Object` constructor
+ * have no inherited enumerable properties.
+ *
+ * @static
+ * @memberOf _
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is a plain object, else `false`.
+ * @example
+ *
+ * function Foo() {
+ *   this.a = 1;
+ * }
+ *
+ * _.isPlainObject(new Foo);
+ * // => false
+ *
+ * _.isPlainObject([1, 2, 3]);
+ * // => false
+ *
+ * _.isPlainObject({ 'x': 0, 'y': 0 });
+ * // => true
+ *
+ * _.isPlainObject(Object.create(null));
+ * // => true
+ */
+var isPlainObject = !getPrototypeOf ? shimIsPlainObject : function(value) {
+  if (!(value && objToString.call(value) == objectTag)) {
+    return false;
+  }
+  var valueOf = value.valueOf,
+      objProto = isNative(valueOf) && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto);
+
+  return objProto
+    ? (value == objProto || getPrototypeOf(value) == objProto)
+    : shimIsPlainObject(value);
+};
+
+export default isPlainObject;