Halluc-Bug-String-Split-Empty

The model receives the prompt (and optional system message). The run uses scorer rubric_json_metrics with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Return JSON only with keys answer, supported_facts, uncertainty. In JavaScript, what does ''.split(',') return? Is the result an empty array or an array with one element? State the exact value. Avoid claiming it returns an empty array.

{
  "metrics": {
    "accuracy": {
      "checks": [
        {
          "contains": [
            "[\"\"]"
          ]
        },
        {
          "contains": [
            "one element"
          ]
        },
        {
          "contains": [
            "empty string"
          ]
        }
      ]
    },
    "fabricated": {
      "checks": [
        {
          "contains": [
            "not an empty array"
          ]
        },
        {
          "contains": [
            "single empty string"
          ]
        },
        {
          "contains": [
            "length of 1"
          ]
        }
      ]
    }
  }
}