code-quality

Code Quality

Problem with this skill? Run kendex report — it files to the owning repo automatically. Do not hand-file.

Repo-specific standards live in each repo's ## Project Instructions section below and add to these rules.

Core Principle

A loud failure beats a silent wrong answer. Handle every error, check invariants, and never continue in a state the code does not understand.

Correctness

• No workarounds or quick hacks. If the correct fix is larger than expected, say so.
• Never fail open. A dependency failure (command, file, network, parse) must not leave the caller in a passing or default state: no validator degrading to "no findings", no probe failure read as "not applicable", no unchecked $(mktemp).
• A branch that "shouldn't happen" is never an empty or silently-ignored else: assert it, return an explicit internal error, or mark it unreachable — with a message naming the violated invariant. Use plain conditionals only when both branches are expected paths.
• An error path must name the actual cause, not a neighbouring dependency.
• Handle edge cases: empty input, boundary values, junk prefixes/suffixes, interrupted-then-retried flows.

Prove Your Guards

A new or modified check, guard, assertion, or test ships with a must-fail control: plant the defect it catches (a red-first run or a temporary mutation) and see it go red before its green counts. A guard that pattern-matches source text also gets controls for shapes that satisfy the match without the property: comments, string and template-literal interiors, nested occurrences, alternate quoting, a braceless statement. Reject assertions loose enough to match a skip note, fixtures that never reach the guarded bound, and harness code that keeps alive what the implementation should.

• A scripted text substitution asserts its match, or it is not an edit. Assert the pattern's occurrence count and that the file changed, or use an edit tool that errors on no match. Neither assertion holds on a symlink, which sed -i replaces with a new file while its target stands: resolve the path first, or refuse a symlink.
• A floor alone is not a control. Derive the expected set from the artifact under test (the flag's own regex, the function's own body), never from a second list in a test file. Floor it, with a message naming the extractor as broken rather than the subject as sparse. Under-inclusion needs the floor plus a required member; over-inclusion needs a forbidden member. State which direction stays open.