I noticed this while testing T138104: Do not serialize empty containers (descriptions/aliases/sitelinks) as empty array [] on Commons – for example, https://commons.wikimedia.org/wiki/Special:EntityData/M52609519.json now looks like this:
{ "entities": { "M52609519": { "pageid": 52609519, "ns": 6, "title": "File:Wikidata time-latitude visualization - 2016-10-24.png", "lastrevid": 334910923, "modified": "2019-01-15T10:44:57Z", "type": "mediainfo", "id": "M52609519", "labels": { "en": { "language": "en", "value": "The x-axis (left/right) represents time, the y-axis (top/down) represents space / geolocation." }, "fr": { "language": "fr", "value": "Visualisation de Wikidata" } }, "descriptions": {}, "statements": [] } } }
The statements (why aren’t they called claims as in Wikidata, by the way? T149410) should be an empty object, not an empty array. Compare with https://commons.wikimedia.org/wiki/Special:EntityData/M77486990.json:
{ "entities": { "M77486990": { "pageid": 77486990, "ns": 6, "title": "File:Andrejeva von Skilondz, opera singer - SMV - NS052.tif", "lastrevid": 347257955, "modified": "2019-04-25T19:53:39Z", "type": "mediainfo", "id": "M77486990", "labels": {}, "descriptions": {}, "statements": { "P180": [ { "mainsnak": { "snaktype": "value", "property": "P180", "datavalue": { "value": { "entity-type": "item", "numeric-id": 4681829, "id": "Q4681829" }, "type": "wikibase-entityid" } }, "type": "statement", "id": "M77486990$acff4b81-447c-f94b-ec62-5c0162841d22", "rank": "normal" } ] } } } }