LowFile-scopeJava Plug & play

JUnit 5: assertThrows and timeouts for slow paths

Use assertThrows for exception cases and annotate long-running tests with @Timeout to bound execution; use @TempDir for file I/O.

Why this matters

Explicit exception and time boundaries reduce flakiness and hangs.

Side-by-side examples engineers can pattern-match during review.

Avoid

@Test void parses(){ new Parser().parse(null); / no assertion / }

Prefer

@Test @Timeout(2)
void parses(){
 assertThrows(NullPointerException.class, () -> new Parser().parse(null));
}

Good

assertThrows(IllegalArgumentException.class, () -> f())

Bad

@Test void x(){ f(); } // no asserts

From the same buckets as this rule.

Critical
No live network or DB in unit tests—use fakes/mocks
Unit tests must stub or fake external HTTP/DB calls; allow real I/O only in integration/e2e tests tagged accordingly.
testing-qualityperformance-efficiency+1
High
Behavioral changes must add or update tests
If files under src/ change behavior, the PR must include tests/ updates or a PR description line no-tests: <reason> explaining why tests are unaffected.
testing-qualitypr-hygiene
High
Block real PAN/SAD in fixtures and test data
Reject PRs adding real PAN/CVV in fixtures, seeds, or mocks. Only use Luhn-valid test PANs from the gateway or opaque tokens (e.g., tok_) and never include CVV. Add a check to fail if a PAN regex is matched. (PCI DSS data minimization)
compliance-pci-dsstesting-quality+1