Optional index?: numberThe index of the failed value, if the current parsed data is an array.
Optional key?: stringThe key of the failed value, if the current parsed data is an object.
Optional path?: ErrorPathIf the value is a construct, like an array or an object, this value contains the next step to retrieve the failed value.
The path to the failure case in the parsed object. Recursively follow the
pathproperty to find the failed value after a validation.