test-gap-review
Review whether existing tests and verification credibly prove a scoped behavior contract. Use during validation when evidence may omit important behavior or provide false confidence.
SKILL.mdplugins/yarstack/skills/test-gap-review/SKILL.md
GitHubTest Gap Review
Audit verification sufficiency without silently becoming a test-writing or production implementation workflow.
Workflow
- Establish the authoritative behavioral contract, comparison scope, and claimed verification.
- Map invariants, assumptions, normal behavior, important boundaries, meaningful failures, preserved state, cleanup, and external effects to existing evidence.
- Identify weak assertions, fixtures that cannot fail meaningfully, implementation-detail tests, expected values derived from the code under test, mocks of code the system owns, coverage numbers cited as proof, unsupported manual claims, and skipped required commands. Flag example-only evidence when the claim spans a broad input space, operation sequence, concurrent ordering, restart, or recovery, and check that generated failures are reproducible.
- For each high-risk claim, ask whether its test would fail if the behavior broke. Reason through a likely mutation, such as a flipped condition, a removed call, or an off-by-one bound. Run a temporary mutation only in a scratch copy, never in the user's working tree.
- Review changed test code as maintained product code. Flag unclear naming or structure, repeated setup that should use a focused helper, helpers that hide scenario data or mix responsibilities, and table-driven cases that do not share one execution path.
- Report each material gap with the affected claim, missing evidence, consequence, smallest proving check, and residual risk.
- If remediation is authorized, use
test-designfor test changes andbehavior-implementfor production behavior; otherwise remain read-only.
For each material claim report:
VERIFIED | NOT VERIFIED | INCONCLUSIVE
Claim: ...
Evidence: ...
Why: ...
Do not chase coverage percentages, demand a stronger method without a concrete risk, add fake-confidence tests, broaden infrastructure, or change production behavior directly.
Finish when material claims have supported statuses and remaining verification risk is explicit.