Debug-Setstate-Stale-Closure-V2

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 diagnosis, fix, tests. A React-style state setter references the captured state variable directly inside an event handler; under rapid sequential updates the closure holds a stale value and increments are lost. Identify the stale closure bug and fix it.

{
  "metrics": {
    "repro": {
      "checks": [
        {
          "contains": [
            "stale"
          ]
        },
        {
          "contains": [
            "closure"
          ]
        },
        {
          "contains": [
            "rapid"
          ]
        },
        {
          "contains": [
            "lost"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "functional updater"
          ]
        },
        {
          "contains": [
            "prev =>"
          ]
        },
        {
          "contains": [
            "prevState"
          ]
        }
      ]
    },
    "diagnose": {
      "checks": [
        {
          "contains": [
            "stale closure"
          ]
        },
        {
          "contains": [
            "captured value"
          ]
        },
        {
          "contains": [
            "functional update"
          ]
        }
      ]
    }
  }
}