{
  "id": "cli-clean-error-handling",
  "repo": "zz-demo/numkit-cli",
  "origin": {
    "repo": "zz-demo/numkit",
    "lane": "fix-average-empty"
  },
  "name": "handle average's empty-input error cleanly",
  "objective": "numkit's average() now throws RangeError for empty input instead of silently returning NaN. Running `numkit-cli average` with no numbers surfaced that as a raw stack trace. Catch it and print a clean CLI error instead.",
  "status": "claimed",
  "scope": [
    "cli.js",
    "cli.test.js"
  ],
  "trigger": {
    "kind": "manual",
    "proposed_by": "zz-dev"
  },
  "coordinators": [
    "zz-dev"
  ],
  "history": [
    {
      "id": "ask-cdf419f186",
      "type": "ASK",
      "kind": "claim_request",
      "from": "zz-dev",
      "at": "2026-10-10T03:36:04.664Z"
    },
    {
      "id": "answer-70826450b9",
      "type": "ANSWER",
      "ask": "ask-cdf419f186",
      "from": "zz-dev",
      "action": "grant",
      "at": "2026-10-10T03:36:04.665Z"
    },
    {
      "id": "ask-49d08d0fbe",
      "type": "ASK",
      "kind": "submit_changeset",
      "from": "zz-dev",
      "payload": {
        "files": [
          {
            "path": "cli.js",
            "content": "#!/usr/bin/env node\nimport { clamp, average } from \"numkit\";\n\nexport function run(argv) {\n  const [command, ...args] = argv;\n  if (command === \"clamp\") {\n    const [value, min, max] = args.map(Number);\n    return String(clamp(value, min, max));\n  }\n  if (command === \"average\") {\n    return String(average(args.map(Number)));\n  }\n  throw new Error(`Unknown command: ${command}`);\n}\n\n// numkit's average() now throws RangeError on empty input (it used to\n// silently return NaN) -- without this, that surfaced as a raw,\n// unfriendly stack trace instead of a clean CLI error.\nexport function main(argv) {\n  try {\n    return { ok: true, output: run(argv) };\n  } catch (err) {\n    return { ok: false, message: err instanceof Error ? err.message : String(err) };\n  }\n}\n\nif (import.meta.url === `file://${process.argv[1]}`) {\n  const result = main(process.argv.slice(2));\n  if (result.ok) {\n    console.log(result.output);\n  } else {\n    console.error(`error: ${result.message}`);\n    process.exit(1);\n  }\n}\n"
          },
          {
            "path": "cli.test.js",
            "content": "import { test } from \"node:test\";\nimport assert from \"node:assert/strict\";\nimport { run, main } from \"./cli.js\";\n\ntest(\"clamp command clamps into range\", () => {\n  assert.equal(run([\"clamp\", \"15\", \"0\", \"10\"]), \"10\");\n});\n\ntest(\"average command averages its arguments\", () => {\n  assert.equal(run([\"average\", \"1\", \"2\", \"3\"]), \"2\");\n});\n\ntest(\"unknown command throws\", () => {\n  assert.throws(() => run([\"nope\"]), /Unknown command/);\n});\n\n// Regression test for numkit's fix-average-empty: average([]) used to\n// return NaN silently; now it throws, and the CLI must surface that as\n// a clean error instead of an unhandled exception.\ntest(\"average with no numbers reports a clean error, not a crash\", () => {\n  const result = main([\"average\"]);\n  assert.equal(result.ok, false);\n  assert.match(result.message, /must not be empty/);\n});\n"
          }
        ],
        "message": "Handle numkit's average() empty-input error cleanly"
      },
      "at": "2026-10-10T03:36:04.665Z"
    },
    {
      "id": "answer-95b19d6589",
      "type": "ANSWER",
      "ask": "ask-49d08d0fbe",
      "from": "zz-dev",
      "action": "grant",
      "payload": {
        "commit": "cb061f703b5d5dbd2a84652a52e416ff65003f1a"
      },
      "at": "2026-10-10T03:36:04.686Z"
    },
    {
      "id": "ask-728971ebd5",
      "type": "ASK",
      "kind": "merge_request",
      "from": "zz-dev",
      "payload": {
        "ladder": [
          {
            "path": "cli.js",
            "kind": "file"
          },
          {
            "path": "cli.test.js",
            "kind": "file"
          }
        ]
      },
      "at": "2026-10-10T03:36:04.686Z"
    },
    {
      "id": "answer-4145858612",
      "type": "ANSWER",
      "ask": "ask-728971ebd5",
      "from": "zz-dev",
      "action": "grant",
      "at": "2026-10-10T03:36:04.700Z"
    }
  ],
  "related_lanes": []
}