Code Health Check

_code-health-check

Overview

Systematic quality verification before code commits. Prevents errors and maintains code health.

When to use: After editing files, before sending PR, before committing code

Process: 5 automated checks catching most issues early

Pre-commit Checklist

1. TypeScript Errors (IDE & Compilation)

# Check VSCode problems panel (Cmd+Shift+M)
# Look for red errors (not just warnings)

# Command-line verification
npx tsc --noEmit

Action:

• ❌ Red errors → Must fix before commit
• ⚠️ Yellow warnings → Review, fix if serious
• ✅ Zero errors → Clear to continue

2. Linting & Code Style

# Run linter
npm run lint

# Auto-fix common issues
npm run lint:fix

Common issues:

• Unused imports/variables
• Inconsistent formatting
• Missing semicolons
• Line too long

3. Build Verification

# Build to catch compilation errors
npm run build

# Verify build succeeds with zero errors
# Check build/ or dist/ output

Must pass: No build errors

4. Test Suite

# Run all tests
npm run test:run

# Coverage report
npm run test:coverage

# Target: ≥70% line coverage

Check:

• All tests pass
• Coverage ≥70%
• New code has tests

5. Pre-push Hook (if configured)

# Comprehensive check before push
npm run pre-push

# Typically includes:
# - TypeScript check
# - Linting
# - Tests
# - Build

Quick Workflow

# 1. Edit files
# ... (editing done)

# 2. Fix issues
npm run lint:fix        # Auto-fix style issues
npm run build           # Check compilation
npm run test:run        # Run tests
npm run pre-push        # Final check

# 3. Review output
# - If all pass → Ready for commit
# - If fails → Fix and repeat step 2

Error Categories & Fixes

Common Issues

Issue: "Cannot find module"

# Solution: Verify import path
# 1. Check file exists at path
# 2. Verify correct relative path
# 3. Update import path

Issue: "Type expectation"

# Solution: Use _typescript-type-safety skill
# 1. Review type definition
# 2. Provide all required fields
# 3. Use correct enum values

Issue: Tests failing

# Solution: Debug test failure
npm run test:run -- --reporter=verbose
# Review actual vs expected
# Fix code or test as needed

Issue: Build fails

# Solution: Check build output
npm run build 2>&1 | head -20
# Address first error
# Retry build

Checklist Before Commit

## Pre-commit Verification

- [ ] VSCode Problems panel: 0 errors
- [ ] `npm run lint`: 0 errors
- [ ] `npm run build`: Success
- [ ] `npm run test:run`: All pass
- [ ] Coverage report ≥70%
- [ ] `npm run pre-push`: All pass (if available)
- [ ] Commit message formatted (_git-commit skill)

Best Practices

1. Run checks frequently during development, not just before commit
2. Fix issues immediately - easier when context is fresh
3. Use IDE warnings as early signals
4. Automate where possible - pre-commit hooks, lint-staged
5. Review build output - don't just check exit code

Related Skills

• _git-commit: Ensure commit message format
• _typescript-type-safety: Fix type-related errors
• _release-process: Quality gates for releases