firestore/internal/conformance/testdata/update-paths-fp-dup-transforms.json

{
  "tests": [
    {
      "description": "update-paths: duplicate field path with only transforms",
      "comment": "The same field cannot occur more than once, even if all the operations are transforms.",
      "updatePaths": {
        "docRefPath": "projects/projectID/databases/(default)/documents/C/d",
        "fieldPaths": [
          {
            "field": [
              "a"
            ]
          },
          {
            "field": [
              "b"
            ]
          },
          {
            "field": [
              "a"
            ]
          }
        ],
        "jsonValues": [
          "[\"ArrayUnion\", 1, 2, 3]",
          "\"ServerTimestamp\"",
          "[\"ArrayUnion\", 4, 5, 6]"
        ],
        "isError": true
      }
    }
  ]
}