{
  "tests": [
    {
      "description": "update-paths: nested ArrayUnion field",
      "comment": "An ArrayUnion value can occur at any depth. In this case,\nthe transform applies to the field path \"b.c\". Since \"c\" is removed from the update,\n\"b\" becomes empty, so it is also removed from the update.",
      "updatePaths": {
        "docRefPath": "projects/projectID/databases/(default)/documents/C/d",
        "fieldPaths": [
          {
            "field": [
              "a"
            ]
          },
          {
            "field": [
              "b"
            ]
          }
        ],
        "jsonValues": [
          "1",
          "{\"c\": [\"ArrayUnion\", 1, 2, 3]}"
        ],
        "request": {
          "database": "projects/projectID/databases/(default)",
          "writes": [
            {
              "update": {
                "name": "projects/projectID/databases/(default)/documents/C/d",
                "fields": {
                  "a": {
                    "integerValue": "1"
                  }
                }
              },
              "updateMask": {
                "fieldPaths": [
                  "a",
                  "b"
                ]
              },
              "currentDocument": {
                "exists": true
              }
            },
            {
              "transform": {
                "document": "projects/projectID/databases/(default)/documents/C/d",
                "fieldTransforms": [
                  {
                    "fieldPath": "b.c",
                    "appendMissingElements": {
                      "values": [
                        {
                          "integerValue": "1"
                        },
                        {
                          "integerValue": "2"
                        },
                        {
                          "integerValue": "3"
                        }
                      ]
                    }
                  }
                ]
              }
            }
          ]
        }
      }
    }
  ]
}