KPI: Code Quality

Definition: The degree to which code is correct, maintainable, and follows established patterns.

Why This Matters

Code quality directly impacts:

• Velocity - Clean code is easier to change
• Reliability - Quality code has fewer bugs
• Collaboration - Consistent patterns reduce friction

Metrics

Primary Metrics

| Metric | Target | Measurement | |--------|--------|-------------| | Lint Errors | 0 | npm run lint:check | | Type Errors | 0 | npm run typecheck | | Test Pass Rate | 100% | npm run test | | Build Success | Yes | npm run build |

Secondary Metrics

| Metric | Target | Measurement | |--------|--------|-------------| | Test Coverage | >80% | Coverage report | | Cyclomatic Complexity | <10 per function | Static analysis | | Code Duplication | <5% | Duplicate detection |

Measurement

Verification Pipeline

The primary quality gate is:

./verify.sh --ui=false

This runs:

1. Format check
2. Lint check
3. Type check
4. Unit tests
5. Build

All stages must pass.

Individual Checks

npm run format:check  # Formatting
npm run lint:check    # Linting
npm run typecheck     # TypeScript
npm run test          # Tests
npm run build         # Build

Improvement Strategies

1. Fix Forward

When you encounter an error:

1. Fix it immediately
2. Record the pattern in typescript-coding skill
3. Prevent recurrence through documentation

2. Type Everything

Eliminate any types. Strong types catch bugs at compile time.

3. Test First

Write tests before or alongside implementation. Tests are documentation that runs.

4. Follow Patterns

Use established patterns from coding-patterns skill:

• Contract-port architecture
• Explicit dependency injection
• Hermetic primitives

5. Review Lint Rules

If a lint rule is consistently violated:

• Either the rule is wrong (propose removing it)
• Or the pattern is wrong (fix the code)

Quality Checklist

Before creating a PR:

• [ ] npm run lint:check passes
• [ ] npm run typecheck passes
• [ ] npm run test passes
• [ ] npm run build passes
• [ ] No any types added
• [ ] New code has tests
• [ ] Error handling follows patterns

Blockers to Watch

| Issue | Detection | Resolution | |-------|-----------|------------| | Lint errors | lint:check fails | Run npm run lint to auto-fix | | Type errors | typecheck fails | Fix types, avoid any | | Test failures | test fails | Debug and fix tests | | Build errors | build fails | Check for missing exports |

Anti-Patterns

• Disabling rules - Don't // biome-ignore without good reason
• Using any - Defeats the purpose of TypeScript
• Skipping tests - Untested code is broken code waiting to happen
• Copy-paste - Duplicated code diverges and rots