Bump to v3.0.0.

lang/isNaN.js

@@ -0,0 +1,35 @@
+import isNumber from './isNumber';
+
+/**
+ * Checks if `value` is `NaN`.
+ *
+ * **Note:** This method is not the same as native `isNaN` which returns `true`
+ * for `undefined` and other non-numeric values. See the [ES5 spec](https://es5.github.io/#x15.1.2.4)
+ * for more details.
+ *
+ * @static
+ * @memberOf _
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
+ * @example
+ *
+ * _.isNaN(NaN);
+ * // => true
+ *
+ * _.isNaN(new Number(NaN));
+ * // => true
+ *
+ * isNaN(undefined);
+ * // => true
+ *
+ * _.isNaN(undefined);
+ * // => false
+ */
+function isNaN(value) {
+  // An `NaN` primitive is the only value that is not equal to itself.
+  // Perform the `toStringTag` check first to avoid errors with some host objects in IE.
+  return isNumber(value) && value != +value;
+}
+
+export default isNaN;