Syntax for filtering by key existence (equivalent to @..key)

[djs0109]

Hi!

I am trying to filter a JSON array to select objects that match a specific attribute and possess a specific key.

In standard JSONPath (RFC 9535), I can achieve this using the existence check syntax ?(@..key). Here is an example dataset

[
  {
    "id": "room1",
    "type": "HotelRoom",
    "hasLocation": {
      "type": "Relationship",
      "value": "fiware_hotel",
      "metadata": {}
    },
    "name": {
      "type": "Text",
      "value": "fiware_room_base_1_v2",
      "metadata": {}
    },
    "temperature": {
      "type": "Number",
      "value": 0.0,
      "metadata": {}
    }
  },
  {
    "id": "room2",
    "type": "HotelRoom",
    "hasLocation": {
      "type": "Relationship",
      "value": "fiware_hotel",
      "metadata": {}
    },
    "name": {
      "type": "Text",
      "value": "fiware_room_base_1_v2",
      "metadata": {}
    },
    "co2": {
      "type": "Number",
      "value": 0,
      "metadata": {}
    }
  }
]

In this case, I want to select the room2, which has the key co2. I can use $[?(@.type == "HotelRoom" && @.co2)] to achieve it. You can test it here.

However, since this library uses a specific expressions for filtering, I am struggling to find the equivalent syntax to check if a key exists within the current object. I have tried $[?(@.type == "HotelRoom" and @.co2)], but it does not work. Could you give me any suggestion or maybe this is a not supported feature?

Thanks!