# Coverage

> Check test coverage for unstaged changes. Use when user asks to "check coverage", "/coverage", or wants to see which unstaged changes lack test coverage.

- Skill: `majiayu000/coverage-3` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/coverage-3`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/coverage-3/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/coverage-3

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# Coverage Check

## Context

Run in parallel:
- `git diff --name-only` - get unstaged files
- `git diff -U0 --no-color` - get changed line numbers

## Commands

Sequential:
1. `npm run test:ci` - vitest with coverage
2. `npm run coverage:report` - generate lcov/text reports

## Workflow

1. Get unstaged files and line ranges (parallel):
   - `git diff --name-only`
   - `git diff -U0 --no-color`
2. Run coverage:
   - `npm run test:ci`
   - `npm run coverage:report`
3. Parse `coverage/lcov.info` (see `lcov-format.md` for format details)
4. Map changed lines to coverage data
5. Report uncovered lines: `file.ts:42`
6. Summary: X/Y changed lines covered

## Rules

- Only analyze unstaged changes (`git diff`)
- Use sequential commands: `test:ci` then `coverage:report`
- Parse lcov.info for coverage data
- Report uncovered lines: `file.ts:42`
- Ignore files without coverage data (non-code files)