verification git:20260910.1df6a07A

Immutable. This exact content is served forever at /api/v1/blob/d38f54b34b0d8846.

---
name: verification
description: |
  Verification discipline: task completion is not goal achievement. Covers the gate
  function, self-critique gate, validation levels, evidence array protocol, and
  goal-backward lens. Loaded by integration-verifier, component-builder, and bug-investigator.
allowed-tools: Read Bash Grep Glob
user-invocable: false
---

# Verification

**Task completion is not goal achievement.** Verify that the phase achieved its goal, not that prior agents said it did. If you cannot independently reproduce a claimed success, return FAIL.

## Reference Files

- `references/live-production-testing.md` — live/production verification strategy

## The Gate Function

```
COMPLETION → TRUTH → PROOF
```

1. **Completion:** Did the agent finish its task? (contract says PASS)
2. **Truth:** Is the work actually correct? (independent verification)
3. **Proof:** Can you prove it with evidence? (exit codes, test output, screenshots)

A PASS without proof is a claim.

<!-- Authoring rule (maintenance, not runtime): every gate in this skill encodes an observed failure mode; understand what a gate prevents before removing it. -->

## Self-Critique Gate (BEFORE Verification Commands)

Before running any test, audit your own work:

**Code Quality:**

- [ ] No TODO/FIXME/stubs in changed files
- [ ] No commented-out code
- [ ] No debug logging left in
- [ ] Error handling covers the failure modes the change introduces
- [ ] Types are correct (not `as any` or `as unknown`)

**Implementation Completeness:**

- [ ] Every acceptance criterion from the plan has corresponding code
- [ ] Every named scenario has a test
- [ ] Every error path in the plan has handling
- [ ] No silent failures (empty catches, discarded errors)
- [ ] Build succeeds, type-check passes

**Self-Critique Verdict:** If any check fails, fix it BEFORE running verification. Don't run tests you know will fail on code quality issues — a known-failing run produces noise evidence that then has to be explained away.

## Validation Levels

| Level | What | Exit Code | When |
| ------- | ------ | ----------- | ------ |
| **Deterministic** | Automated test | 0/1 | Always — the default |
| **Probabilistic** | Test with known flake rate | 0/1 (retry policy) | When deterministic impossible (timing, network) |
| **Manual** | Human verifies with checklist | n/a | When automation not worth the cost |
| **Live** | Production-like environment | 0/1 | When plan requires live proof |

Every verification must state its validation level — unlabeled evidence lets weak proof masquerade as strong. If manual, state the checklist. If deterministic, state the command + exit code. If live, state the harness command.

## Production-Like Live Proof

When the plan includes `### Live Verification Strategy` or a harness manifest:

- Run `python3 "${CLAUDE_PLUGIN_ROOT}/tools/live_harness_runner.py" --manifest <path> --mode proof`
- If stress required: also run `--mode stress`
- Do NOT silently substitute replay fixtures or unit tests for required live proof

**Flaky test handling:** re-run once — one retry separates environment blips from real flake; more retries launder genuine failures. Pass on re-run → mark PASS with `flaky: true`. Fail both → FAIL. Never convert flaky pass into unconditional confidence.

## Evidence Array Protocol (MANDATORY for PASS)

```
EVIDENCE:
  scenarios:
    - "[name] | Given [state] | When [action] | [command] → exit [code] | expected=[expected] | actual=[actual]"
  regressions:
    - "[test] → exit [code]: [result]"
  edge_cases:
    - "[case]: [command] → exit [code]: [result]"
```

Every scenario needs non-empty Expected and Actual. Every scenario maps to exactly one EVIDENCE entry. SCENARIOS_PASSED must equal EVIDENCE.scenarios with exit 0 + Result=PASS. Run each check against the revision being verified; if the code changes after a check, re-run the affected scenarios before citing them. Record the tested identity with the evidence: the commit SHA, plus a patch or digest when the tree is dirty; evidence that does not identify the revision it was produced from is unverified, not PASS.

## Goal-Backward Lens

Walk backward from the goal to verify it was achieved:

1. **What was the goal?** (re-read the plan's exit criteria)
2. **What would prove it?** (name the specific evidence)
3. **Do I have that evidence?** (run the verification)
4. **Does the evidence actually prove the goal?** (not "tests pass" but "the tests test the right thing")

## Common Failures

| Failure | What happens | Fix |
| --------- | ------------- | ----- |
| **False green** | Test passes without exercising the real code path | Test Honesty Gates (see integration-verifier) |
| **Tautological check** | Expected value recomputed the way the code computes it, e.g. `expect(add(a, b)).toBe(a + b)` — passes by construction | Expected values come from an independent source of truth: a known-good literal, a worked example, the spec |
| **Scope skip** | "All tests pass" but untested scenarios exist | Goal-backward lens: name every scenario, verify each |
| **Stale evidence** | "Tests pass" but you didn't run them this session | Re-run. Evidence must be from THIS session. |
| **Claim without proof** | "It works" with no command/exit code | Evidence array is mandatory for PASS |
| **Pointer-as-proof** | Path cited as PASS without re-opening it | Re-open the artifact; if it does not show the claim, downgrade or re-run. Never cite it as PASS |
| **Untested claim** | A scenario or claim the return never addresses | Mark it untested with its reason; never assume it passed |
| **Environment escape** | Test fails with env signal (command not found, ECONNREFUSED) | Classify as ENVIRONMENT not code. Mark BLOCKED. |

## Excuses and Tells

If you catch yourself in the left column before a PASS, do the right column first.

| Excuse or tell | Reality |
| ---------------- | -------- |
| "Should work now" / "looks good" / "seems fine" / "probably" | RUN the verification command. "Should" is not evidence. |
| "I'm confident it works" | Confidence is not evidence. Exit code 0 is evidence. |
| "Builder reported success" / "the agent said it passed" | Verify independently. Agents can be wrong or sycophantic. |
| "The tests cover this" | Name the specific test — or it isn't covered. |
| "No regressions detected" | List what was tested — or nothing was. |
| "Tests passed before" (another session) | Stale evidence. Re-run in THIS session. |
| "It's just a typo fix" / "it's trivial" | Small changes break things too. Run the tests. |
| "I'll verify after commit" / committing without fresh evidence | Verify BEFORE commit. A broken commit is harder to revert. |
| "The build succeeded so it works" | Build success ≠ correct behavior. Run behavioral tests. |
| "I don't need to run the full suite" | If your change touches shared code, you do. |
| Satisfaction before seeing exit code 0 | Evidence first, satisfaction after. |
| Weakening an assertion to make a test pass | That launders the failure. Fix the code, not the test. |