firestore/internal/conformance/testdata/set-del-wo-merge.json

{
  "tests": [
    {
      "description": "set: Delete cannot appear unless a merge option is specified",
      "comment": "Without a merge option, Set replaces the document with the input\ndata. A Delete sentinel in the data makes no sense in this case.",
      "set": {
        "docRefPath": "projects/projectID/databases/(default)/documents/C/d",
        "jsonData": "{\"a\": 1, \"b\": \"Delete\"}",
        "isError": true
      }
    }
  ]
}