{
  "schemaVersion": 1,
  "id": "prometheus-stale",
  "name": "Prometheus becomes stale",
  "description": "Tests that missing current metrics become Unknown rather than remaining healthy.",
  "initialState": {
    "sources": {
      "prometheus": "healthy"
    },
    "host": {
      "status": "operational",
      "cpuPercent": 20
    }
  },
  "timeline": [
    {
      "atSeconds": 0,
      "action": "set-metric",
      "payload": {
        "metric": "host.cpu.utilization",
        "value": 20
      }
    },
    {
      "atSeconds": 30,
      "action": "disconnect",
      "payload": {
        "source": "prometheus"
      }
    }
  ],
  "expectedOutcomes": [
    {
      "bySeconds": 90,
      "assertion": "Prometheus datasource is delayed or stale according to policy."
    },
    {
      "bySeconds": 180,
      "assertion": "Required metric-derived host state is unknown, not operational."
    },
    {
      "bySeconds": 180,
      "assertion": "A datasource alert exists without resolving unrelated existing firing alerts."
    },
    {
      "bySeconds": 190,
      "assertion": "Previous values, if shown, include their age."
    }
  ]
}