Painless scripting initialize new array

Question

I'm trying to add or update a nested object in Elasticsearch using a script. Below script works fine if integrations is already an array, but when it is null, below script throws a null pointer exception. How do I initialize ctx._source.integrations to be an empty array if its value is null? (Something like the equivalent of JavaScript's myObject.integrations = myObject.integrations ?? [])

POST /products/_update/VFfrnQrKlC5bwdfdeaQ7
{
  "script": {
    "source": """
      ctx._source.integrations.removeIf(i -> i.id == params.integration.id);
      ctx._source.integrations.add(params.integration);

      ctx._source.integrationCount = ctx._source.integrations.length;
    """,
    "params": {
      "integration": {
        "id": "dVTV8GjHj8pXFnlYUUlI",
        "from": true,
        "to": false,
        "vendor": "sfeZWDpZXlF5Qa8mUsiF",
        "targetProduct": {
          "id": "nyILhphvCrGYm53cfaOx",
          "name": "Test Product",
          "categoryIds": []
        }
      }
    }
  }
}

Answer 1

ok i think this does the trick:

if (ctx._source.integrations == null) {
  ctx._source.integrations = new ArrayList();
}

is there a short hand to this like in the JS example?