Write Unit Tests

If tests exist: read them. Determine what's missing, not what to replace.

Step 4: Plan Test Coverage

Before writing, list what will be tested:

Test plan for {file}:

Happy path:
- [ ] {scenario}
- [ ] {scenario}

Edge cases:
- [ ] {scenario}
- [ ] {scenario}

Error states:
- [ ] {scenario}

NOT testing (implementation details / framework behavior):
- {list}

Get confirmation from user if test plan is non-obvious, then proceed.

Step 5: Write Tests

Using the test context from Step 1:

• Use the established test file naming and placement
• Use the mock patterns observed in this codebase (not invented ones)
• Use the factory/fixture patterns to build test data
• Use the assertion style consistent with the project

Rules:

• Test behavior, not implementation details
• Each test has one clear assertion focus
• Mock everything external to the unit under test
• Do not test framework code, trivial getters, or TypeScript-enforced invariants
• Async tests use the project's established async pattern (not invented waitFor usage)

Step 6: Verify

# Run just the new test file
pnpm test {test-file-path} --run 2>&1 | tail -30

If tests fail: diagnose and fix before reporting success.

Step 7: Report

✅ Unit tests written for {file}

Coverage added:
- {scenario tested}
- {scenario tested}

Test file: {path}

REPO=$(git remote get-url origin 2>/dev/null | sed 's/.*\///' | sed 's/\.git//')
BRANCH=$(git branch --show-current 2>/dev/null | sed 's/\//-/g')
TS=$(date +%Y%m%d-%H%M%S)-$$
mkdir -p ~/.claude/skill-output/$REPO/$BRANCH

Write this report to ~/.claude/skill-output/$REPO/$BRANCH/write-unit-tests-report-$TS.md.