Add isNaN to externs of chai.
@@ -369,6 +369,12 @@ assert.isFalse = function(value, opt_message) {};
*/
assert.isNotFalse = function(value, opt_message) {};
+/**
+ * @param {*} value
+ * @param {string=} opt_message
+ */
+assert.isNaN = function(value, opt_message) {};
+
/**
* @param {*} value
* @param {string=} opt_message
