# Fixtures — implemented and runnable

Every fixture here has a `make` target. Run it, see the result. If it
passes, the gate works. If it fails, something is miswired.

For the full catalog of known failure classes (including ideas and
research references), see [FAILURE-CATALOG.md](FAILURE-CATALOG.md).

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## Drills

### F-001: Gate-fires drill (transition guard)

`make drill-transition-guard`

Plants an invalid transition (pending → shipped) and asserts `ValueError`
is raised. Proves the domain guard is on the executed path, not just in
the file.

### F-002: Gate-fires drill (import boundary)

`make drill-import-check`

Plants a forbidden import in the domain layer, asserts `lint-imports`
exits nonzero and names the specific violation, then reverts. Uses
`trap` for unconditional cleanup.

### F-002b: Permission drill (import boundary)

`make drill-import-permit`

Plants a legal import (application → domain) and asserts the linter
does NOT fire. A gate that rejects valid imports is as broken as one
that misses violations.

### F-003: Oracle tampering

`make verify-tamperproof`

Copies verification files to a temp directory before the agent runs.
After changes, runs the check from the trusted copy. The agent can
rewrite its own tests; the copy still catches violations.

⚠ **Metagaming gap:** `verify-tamperproof` prevents modification but
not metagaming. If the agent reads the grader source and optimizes
for specific checks rather than the underlying intent, the oracle is
compromised at a level this fixture does not yet reach. See the
[failure catalog](FAILURE-CATALOG.md#f-003-metagaming) for details.

### F-004: Dead-guard detection

`python scripts/run_evals.py --task dead-guard-detection`

A guard placed in an unreachable code path passes a grep but never fires.
The verifier proves the done-condition is behavioral: run the code,
observe the rejection. Contributed by whitehat-explorer (stranger origin).

### F-009: Dead constraint

`make drill-dead-config`

Scans `pyproject.toml` tool sections for config keys referenced nowhere
in source, scripts, CI, or Makefile. A config key that exists but governs
nothing is the configuration equivalent of dead code.

### F-010: Deny catalog

`make drill-deny-catalog`

20 baseline deny rules across 6 categories, golden-file locked. Checks:
golden parity, additive-only (removals rejected), pattern compilation,
and pattern firing per category.

### F-014: Monitoring coverage gap

`make drill-ci-coverage`

Verifies every verification-ladder `make` target appears in at least one
CI workflow. A check that runs locally but not in CI is enforced by
convention, not by the pipeline.

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## Design principles

1. **Behavioral over textual.** Run the code, observe the result. Don't grep.
2. **Drill proves the gate fires. Stranger proves it catches real failures.**
3. **Silence is not evidence.** A gate that has never fired is indistinguishable
   from a gate that cannot fire.
4. **The printer is part of the system.** Test that the result survives to the consumer.
5. **Separate ran from worked.** Exit code proves the gate ran. Reason string proves it saw the violation.
6. **Test the outcome, not the command.** A guardrail that blocks a command but permits the outcome is not effective.
7. **Classify your oracle.** Native (no model), proxy (model judges), or none (unmeasured).

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Full failure catalog with 14 fixture types, research references, and
contribution items: [FAILURE-CATALOG.md](FAILURE-CATALOG.md)