quality-gates-lens

Observer-only lens that falsifies every claim in the quality-gates evidence log against the real Git tree — without ever executing a build, tests, or mutation run.

Role in the adversarial panel

This lens belongs to software-engineer-reviewer. It is activated on every DELIVER cycle — it is one of the 4 CORE lenses. It receives a single input: the evidence log produced by the software-engineer at the end of the COMMIT phase (.copilot-tracking/skraft-plans/{projectSlug}/evidence/{date}/qg-{story}.json).

graph LR
  SER[software-engineer-reviewer] -->|dispatches| QGL[quality-gates-lens]
  QGL -->|JSON verdict| SER
  QGL -.->|reads only| GIT[(Git tree)]
  QGL -.->|reads only| LOG[(evidence log)]

What the lens checks

Log location: presence, valid JSON, $schema equal to quality-gates-evidence/v1.
Self-consistency (no Git access yet): status: "pass" implies metrics.tests_failed == 0; status: "not_applicable" requires a non-empty rationale; stdout_tail must be a strict suffix of the referenced file.
Falsification against the Git tree: repo_root_rev matches HEAD SHA; each commits_covered[].sha resolves in the tree; files_changed lists exactly the paths in the diff; commits_covered[].subject matches the Conventional Commits regex (G8); stdout_ref files exist and their stdout_sha256 matches re-hashing; RED/GREEN snapshots match git show {commit}:{file}.
G9 — RED→GREEN integrity: any removal or mutation of a line present in the RED snapshot is an Iron Rule violation.

Verdict and thresholds

Condition	Verdict	Severity
Log absent, malformed, or `$schema` unsupported	`inconclusive`	—
Referenced file unreachable or `stdout_sha256` mismatch	`inconclusive`	—
`status: "pass"` with `tests_failed > 0`	`fail`	`high`
`status: "not_applicable"` without `rationale`	`fail`	`high`
`commits_covered[].subject` fails G8 regex	`fail`	`high`
Commit SHA does not resolve, or `files_changed` lists a path absent from the diff	`fail`	`high`
RED→GREEN snapshot: removal or mutation of a line (G9)	`fail`	`blocker`
Every applicable gate at `pass` and every reference resolves	`pass`	—

inconclusive is never equivalent to pass. Absence of evidence is not evidence of success.

Invariants

Read-only: the lens never executes build, tests, mutation, or any mutating Git command.
It accesses the Git tree only via Read, Glob, Grep on the working copy (HEAD).
It does not receive the output of other lenses.
If a claim cannot be falsified from the Git tree alone, the verdict is inconclusive (never pass).

« Absence of evidence is not evidence of absence. » — Scientific verification principle, epistemological tradition.

Sources