Tsurai7 Test adequacy review
A green suite proves nothing about the assertions that cannot fire. This lens judges the tests; it does not write them — but every finding names the missing or corrected test concretely.
Method
- Name vs power. For each test: state the reason it exists (its name and comments claim one), then describe the concrete code change that should make it fail. If no such change exists — because the guarded path is not reachable from the test's setup, or the assertion holds vacuously — that is the top finding class: a test that cannot fail for its named reason. (Mutation thought-experiment; run a real mutation when cheap.)
- Trigger surface. Enumerate every path that can reach the guarded behavior (all call sites, all gateway branches, all event orders). Which does the suite exercise? An untested trigger on a money or safety path is a finding even when the tested trigger is identical-looking code.
- Barriers and time. Every wait must be tied to an observable signal.
sleep(N)as a synchronization barrier, assertions racing a timer, and "must finish before X fires" enforced by nothing are findings — they pass on fast machines and lie on slow ones. - Fixture honesty. A test helper that hand-duplicates a production payload, contract, or constant will drift green: the test keeps passing while production moves. Shared structs/constants between test and prod are the fix; duplication is the finding.
- Isolation and ordering. Global resets (shared stub state, scenario resets) that couple suites, and tests correct only under sequential execution, are findings with a deferred fuse.
Evidence rule: quote the test lines that make each finding true; name the concrete input, timing, or mutation that demonstrates it.
Rules
- Run in a fresh context with only the diff and the test files — not the author's reasoning, not other lenses' output.
- Never rerank against other lenses; adequacy of tests and correctness of code are separate verdicts.
- Findings go to the findings-ledger.
Provenance
Every finding class above shipped past multi-model review at least once in an internal retrospective (2026-08): a feature-off test that could not fail for its named reason, a second trigger branch exercised by zero tests, a 3-second sleep as a barrier, tests racing a short fallback timer, and a helper duplicating the server's start payload. Meta's mutation-guided test generation (FSE 2025) grounds the mutation discipline.