# Coverage Gaps

> Coverage Gaps

- Skill: `archive228/coverage-gaps` (Agent Skill)
- Install (CLI): `npx skillmds@latest add archive228/coverage-gaps`
- Raw SKILL.md: https://api.skillmd.com/api/skills/archive228/coverage-gaps/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: archive228 (https://skillmd.com/u/archive228)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/archive228/coverage-gaps

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# Coverage Gaps
Coverage % is a vanity metric. Hunt the gaps that bite:
- **Error paths** — the 500, the timeout, the empty/null input, the malformed payload. Almost always untested.
- **Boundaries** — 0, 1, max, off-by-one, empty collection.
- **Branches** — every `if/else` and `catch` exercised, not just the happy line.
- **Concurrency / order** — anything stateful tested in isolation AND in sequence.
Skip tests that assert a constructor sets a property — worthless. Test behavior, not implementation. Output: the 3-5 highest-risk untested paths, ranked by blast radius, with the test to add.