@none not supported by LanguageProperty

[jason-fox]

Stellio 2.18.1

Creating an Entity with a language property and the index value @none . According to JSON-LD @none is the equivalent of "default" language, since it isn't "en" or "de" or "jp"

From the JSON-LD Spec

@none

Used as an index value in an index map, id map, language map, type map, or elsewhere where a map is used to index into other values, when the indexed node does not have the feature being indexed.

curl -L 'http://localhost:8080/ngsi-ld/v1/entities/' \
-H 'Content-Type: application/json' \
-H 'Link: <http://context/user-context.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"' \
--data-raw '{
    "id": "urn:ngsi-ld:Building:barn002",
    "type": "Building",
    "name": {
        "type": "LanguageProperty",
        "languageMap": {
            "@none": "The Big Red Barn",
            "en": "Big Red Barn",
            "de": "Große Rote Scheune",
            "ja": "大きな赤い納屋"
        }
    }
}'

Attribute is not created ❌

{
    "type": "https://uri.etsi.org/ngsi-ld/errors/BadRequestData",
    "title": "The JSON-LD object contains a member with invalid characters (4.6.2): @none",
    "status": 400,
    "detail": "If you have difficulty identifying the exact cause of the error, please check the list of some usual causes on https://stellio.readthedocs.io/en/latest/TROUBLESHOOT.html . If the error is still not clear or if you think it is a bug, feel free to open an issue on https://github.com/stellio-hub/stellio-context-broker",
    "instance": "/ngsi-ld/v1/entities"
}

Removing the @none and the LanguageProperty is created just fine.

Also note that since @none is "default", if I make a subsequent GET request with ?lang=fr I would expect to get the @none value as the property value with:

 "name": {
        "type": "Property",
        "value": "The Big Red Barn",
         "lang":   "@none"
    }

In other words "You asked for French, but I don't have a specific French key, so here is the default language".