Optional attributes with null values

[andrejserafim]

If I have an optional field, for exapmle of type string, to be valid a document can either have the string, have the field missing or have null instead of the string. Are my expectations incorrect?

Currently the null case errors with a ValidationException.

[erosb]

or have null instead of the string

Thats incorrect. An optional field with type "string" can be a string or the key can be omitted from the document. But having the key with the null value it will be valid by this schema:

{
    "properties": {
        "myStringProp": {
            "anyOf": [
                { "type": "null"},
                {"type": "string"}
            ]
        }
    }
}

[andrejserafim]

Fair enough - thank you for clarifying.