Represents JSON string.
By default, the type validates the string and throws an error if it is not a valid JSON. If you are sure that the string is valid JSON, you can return instance of JsonStringable (or JsonString) in this case validation will be omitted.
Please note that the scalar doesn't encode/decode value to/from JSON, it just contains a valid JSON string. If you want automatically convert value to/from JSON, you can use the JSON type from mll-lab/graphql-php-scalars package. If you need something more typesafe, consider using Serializer.