# Fidelity Verification — Detailed Processes

> Extracted from `implement/SKILL.md` (Mode: port) Phase A6 and B5.
> Read this file when executing the test porting and fidelity verification phases.

---

## Phase A6 — Port Tests & Verify Fidelity

1. **Port every test** from the source — not just the happy path. Edge cases,
   error paths, and boundary tests must all be ported.
2. **Rewrite assertions** to match the target test framework's assertion style.
3. **Run ported tests** — they must pass. If a test fails:
   - Behavior mismatch: fix the implementation to match source behavior.
   - Test logic error (e.g. wrong assertion library syntax): fix the test.
   - Infrastructure gap (e.g. test tried to connect to Redis): adapt the test
     to the alternative from Phase A4.
4. **Full test suite** — run the target project's existing tests + ported
   tests. No regression in existing tests.
5. **Fidelity checklist** — for each source behavior, verify manually or
   automatically:

### Fidelity Verification Template

```markdown
## Fidelity Verification

| Source Behavior                   | Tested?       | Result | Notes                                        |
| --------------------------------- | ------------- | ------ | -------------------------------------------- |
| User login with valid credentials | ✅ ported     | PASS   |                                              |
| User login with invalid password  | ✅ ported     | PASS   |                                              |
| Session expiry at 1h              | ✅ ported     | PASS   | Adapted to DB session store                  |
| Rate limiting: 5 attempts / min   | ⚠️ not ported | —      | Target has no rate limiting infra → deferred |
```

---

## Phase B5 — Verify (Integration + Fidelity)

After all chunks are implemented and reviewed, run
`core/skills/verify/SKILL.md` with the fidelity baseline
(wiki page `port-{name}/source-analysis/10-fidelity-baseline`, read via `wiki 读写 API（见 TERMINOLOGY）`) as the
acceptance criteria:

- Every `FID-*` item must be traced to a passing test in the target project.
- Full test suite (existing + ported) must pass with no regressions.
- Typecheck and lint must be clean.
- Fidelity deviations from any chunk are consolidated into a final
  fidelity report.
- **Reverse coverage (Ported? audit)**: The Source Function Inventory
  (produced in Phase A1 / B1) "Ported?" column must have **zero** unexplained
  ☐ entries. Any residual ☐ MUST carry a matching `[DEFER]` row — with a
  reactivation trigger — in the Port Fidelity Report. A bare ☐ is a FAIL,
  not a deferral. This closes the #1 port-completeness gap: functions that
  were never ported and never consciously deferred.
- **Symbol-level completeness (SRC-CMP)**: Run an automated export-symbol
  diff between source and target packages. Every source symbol absent from
  the target MUST appear as `[DEFER]` in the report; a silent gap is a FAIL.

  ```bash
  diff <(codegraph exports <source-pkg>) <(codegraph exports <target-pkg>)
  # Each left-only symbol must be DEFER'd or ported — silent gaps fail B5.
  ```

### Port Fidelity Report Template

```markdown
## Port Fidelity Report

| FID-*   | Behavior           | Chunk       | Target Test          | Status |
| ------- | ------------------ | ----------- | -------------------- | ------ |
| FID-001 | Login valid creds  | chunk-auth  | auth/login.test.ts   | PASS   |
| FID-002 | Login invalid pw   | chunk-auth  | auth/login.test.ts   | PASS   |
| FID-004 | Rate limiting      | chunk-auth  | —                    | DEFER  |

**Summary**: {X}/{Y} behaviors verified, {Z} deferred
```