Refactor-Calculator-Operation-Map

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 refactor, rationale, tests. Refactor if/else arithmetic operation dispatch into an operation map. Keep divide-by-zero handling unchanged.

{
  "metrics": {
    "visible": {
      "checks": [
        {
          "contains": [
            "operation map"
          ]
        },
        {
          "contains": [
            "calculator"
          ]
        },
        {
          "contains": [
            "divide"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "divide-by-zero"
          ]
        },
        {
          "contains": [
            "unchanged"
          ]
        },
        {
          "contains": [
            "unknown operation"
          ]
        }
      ]
    },
    "intent": {
      "checks": [
        {
          "contains": [
            "dispatch"
          ]
        },
        {
          "contains": [
            "control flow"
          ]
        },
        {
          "contains": [
            "map"
          ]
        }
      ]
    }
  }
}