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coyote/assets/agents/review-gauntlet/scripts/default_lanes.py
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Dark-Alex-17 ebb9e9af62 fix(TASK-018): harden verdict_gate fault routing and widen default_lanes fallback
Adversary finding 1: verdict_gate treated any lane report CONTAINING
'PIPELINE-FAULT:' as a lane fault, so a real review quoting the marker
silently bypassed red-finding counting and sentinel parsing. Lane-fault
detection is now precise — only a report that IS the lane_fault.py
marker (starts with it) routes to the fault rule. Adds the missing
regression tests: reds block despite MERGE-READY, NEEDS-HUMAN without
reds passes with attention, probe INCONCLUSIVE blocks with the
environment note, a gate crash fails closed, and a quoting report is
routed to the red rule, not the fault rule.

Adversary finding 2: default_lanes overwrote caller-forced lanes and
dropped the security lane the deterministic signals guaranteed. The
fallback now unions its defaults with caller-forced lanes (canonicalized
via the same aliases build_items uses) and forces security on
auth/deps/exec signals or hardened posture — selection degrades wider,
never narrower, and stays deterministic via a fixed lane order. Tests
cover forced-lane survival, alias canonicalization, unknown-name
tolerance, each security signal, and determinism.
2026-09-14 10:50:33 -06:00

91 lines
3.2 KiB
Python

#!/usr/bin/env python3
"""Deterministic lane-selection fallback for the review gauntlet.
Reached ONLY via select_lanes' `fallback:` route, when the additive LLM
judgment dies after retries. Emits `forced_lanes` — code-review + adversary,
plus probe when the deterministic signals flagged a consumer-facing surface,
plus security when the attack-surface signals (auth/deps/exec) or a hardened
posture demand it, unioned with any lanes the caller forced (canonicalized
with the same aliases build_items uses) — which build_items honors exactly,
so selection degrades WIDER, never narrower. The degradation note goes into
`lanes_degraded`; build_items folds it into lanes_summary so the final
report names the degradation.
"""
import json
import os
MAX_DETAIL_CHARS = 500
# Keep in sync with build_items.ALIASES — a caller-forced lane must
# canonicalize the same way here as it would on the non-degraded path.
ALIASES = {
"code-review": "code-review",
"code_review": "code-review",
"code-reviewer": "code-review",
"adversary": "adversary",
"adversarial": "adversary",
"adversarial-review": "adversary",
"security": "security",
"security-review": "security",
"security-reviewer": "security",
"probe": "probe",
"usage": "probe",
"usage-pattern": "probe",
"usage-pattern-testing": "probe",
}
# Stable emission order keeps the fallback deterministic.
LANE_ORDER = ["code-review", "adversary", "security", "probe"]
def load_state():
if path := os.environ.get("GRAPH_STATE_FILE"):
with open(path) as f:
return json.load(f)
return json.loads(os.environ.get("GRAPH_STATE", "{}"))
def main():
state = load_state()
lanes = {"code-review", "adversary"}
if state.get("consumer_surface"):
lanes.add("probe")
# The deterministic security signals are already in state when this
# fallback runs; a degraded selection must never drop the security lane
# build_items' hard rules would have selected.
if (
state.get("touches_auth")
or state.get("touches_deps")
or state.get("touches_exec")
or state.get("security_posture") == "hardened"
):
lanes.add("security")
# Caller-forced lanes survive degradation — union, never overwrite.
for lane in state.get("forced_lanes") or []:
if canon := ALIASES.get(str(lane).strip().lower()):
lanes.add(canon)
forced = [lane for lane in LANE_ORDER if lane in lanes]
raw = state.get("select_lanes_failure")
detail = raw.strip().replace("\n", " ") if isinstance(raw, str) else ""
if len(detail) > MAX_DETAIL_CHARS:
detail = detail[: MAX_DETAIL_CHARS - 1] + "…"
note = "lane selection degraded to deterministic defaults"
if detail:
note += f" — {detail}"
print(json.dumps({"forced_lanes": forced, "lanes_degraded": note}))
try:
main()
except Exception as e: # noqa: BLE001 — the fallback itself must never crash
print(
json.dumps(
{
"forced_lanes": ["code-review", "adversary"],
"lanes_degraded": "lane selection degraded to deterministic "
f"defaults (fallback script error: {e})",
}
)
)