{
 "provenance": {
  "runId": 37077373640,
  "headSha": "147163e0",
  "testName": "plan-eng-coverage-audit",
  "recordedPassed": false,
  "source": "Exact final parent result of the CI capture (paid-slice-12-a1). The diagram follows plan-eng-review's documented CODE PATHS | USER FLOWS layout; a wrapped USER FLOWS row continues on a │ rail beside the covered processPayment row."
 },
 "output": "Test review complete for the two billing functions. Framework detected: vitest (config file and devDependency present), though the `test` script in package.json is a placeholder echo, so the one existing test never runs via `npm test`.\n\n```\nCODE PATHS                                                       USER FLOWS\n[+] src/billing.ts                                               [+] Payment lifecycle (caller-facing)\n  ├── processPayment(amount, currency)                             ├── [GAP] [→E2E] Pay then refund same paymentId\n  │   ├── [★★  TESTED] Happy path USD — billing.test.ts:6           │          (no test chains the two functions)\n  │   │                asserts status only; amount/currency        └── [GAP]        Caller receives rejection error\n  │   │                echo not asserted                                            (no test asserts any thrown message)\n  │   ├── [GAP]        EUR accepted (2nd arm of currency guard, :4)\n  │   ├── [GAP]        amount <= 0 → throws 'Invalid amount' (:3)\n  │   │                boundary 0 and negative both unexercised\n  │   └── [GAP]        Unsupported currency → throws (:4)\n  │                    e.g. 'GBP', '', lowercase 'usd'\n  └── refundPayment(paymentId, reason)                           [+] Error states\n      ├── [GAP]        Happy path → { status: 'refunded' } (:11)   └── [GAP]        Falsy-ID and falsy-reason both\n      ├── [GAP]        !paymentId → throws 'Payment ID required'                    collapse to '' and undefined;\n      │                (:9) '' and undefined unexercised                            neither is exercised\n      └── [GAP]        !reason → throws 'Reason required' (:10)\n                       function is never imported by any test\n\nLLM integration: none in scope — no [→EVAL] paths\n\nCOVERAGE: 1/9 paths tested (11%)  |  Code paths: 1/7 (14%)  |  User flows: 0/2 (0%)\nQUALITY: ★★★:0 ★★:1 ★:0  |  GAPS: 8 (1 E2E, 0 eval)\n```\n\nLegend: ★★★ behavior + edge + error  |  ★★ happy path  |  ★ smoke check\n[→E2E] = needs integration test  |  [→EVAL] = needs LLM eval\n\n**Coverage summary**\n\n- **processPayment** has one happy-path test rated ★★. It only checks the status field, so a regression that mangled the returned amount or currency would pass. Both guard clauses and the EUR arm are untested.\n- **refundPayment** has zero coverage. It is not imported anywhere in the test directory, so all three branches are gaps.\n- **No error message is asserted anywhere.** The four throw sites are the only behavior that protects callers from bad input, and none has a test that would catch the guard being removed or inverted.\n- **The branch diff itself adds no behavior.** It only appends a comment to each file, so the gaps above are pre-existing on main, not introduced by this branch.\n- **The pay-then-refund flow has no test**, and both functions are pure with no integration boundary yet. Unit tests are the right tool for every code-path gap. The lifecycle row is flagged E2E only because the matrix says payment flows should not rely on unit tests alone once a real boundary exists.\n\nPer the requested scope I did not write the Test Plan Artifact, propose tests through the decision gate, or modify the source or tests."
}