Code Quality

Code Quality Assessment & Improvement Skill

Systematic code quality analysis, metric tracking, and improvement sprint planning for TypeScript/React projects.

Quick Commands

• /code-quality assess - Run full assessment and generate report
• /code-quality metrics - Show current metrics vs targets
• /code-quality hotspots - Identify highest-priority improvement areas
• /code-quality sprint - Plan a focused improvement sprint

Workflow

Phase 1: Assessment

Run comprehensive code quality checks and establish baseline metrics.

Required Checks:

1. Lint Analysis

   npm run lint
   

   • Target: 0 errors, 0 warnings
   • Track: Total warnings by category

2. Type Safety

   npm run type-check
   

   • Target: 0 TypeScript errors
   • Track: Error count and locations

3. Test Coverage

   npx vitest run --coverage
   

   • Target: 80%+ line coverage
   • Track: Coverage by directory

4. Code Duplication

   npx jscpd src --reporters json --output duplication-report
   

   • Target: <2% duplication
   • Track: Percentage and clone locations

5. any Type Count Use the Grep tool with pattern : any on src/, glob *.{ts,tsx}, output_mode count. Exclude test files by filtering results.

   • Target: <50 any types
   • Track: Count by file

6. Large File Detection Use the Glob tool with pattern src/**/*.{ts,tsx}, then Read each file to check line count. Sort results by size.

   • Target: No files >500 lines (excluding data files)
   • Track: Files exceeding threshold

7. Complexity Analysis (if eslint-plugin-complexity configured)

   npx eslint src --rule 'complexity: [warn, 15]'
   

   • Target: No functions with complexity >15
   • Track: High-complexity function locations

Phase 2: Hotspot Identification

Prioritize issues using the Impact/Effort Matrix:

Hotspot Detection:

• Files with most any types: Use the Grep tool with pattern : any, glob *.{ts,tsx}, path src/, output_mode count. Exclude test files. Sort by count descending.
• Largest non-test files: Use the Glob tool with pattern src/**/*.{ts,tsx}. Skip files matching .test. or __tests__. Read each to get line count, then rank by size.
• Duplicate code locations: Use the Read tool on duplication-report/jscpd-report.json and parse the duplicates array to find the most-repeated file paths.

Phase 3: Sprint Planning

Structure improvement work into focused sprints:

Sprint Template:

## Sprint [N]: [Theme]

**Duration**: [X] hours
**Goal**: [Specific, measurable objective]

### Tasks
| ID | Task | Effort | Impact |
|----|------|--------|--------|
| 1 | [Task description] | [hours] | [metric improvement] |

### Success Criteria
- [ ] Metric A: [before] → [target]
- [ ] Metric B: [before] → [target]

### Validation
- [ ] All tests pass
- [ ] Lint clean
- [ ] Type-check clean
- [ ] No regressions

Sprint Sizing Guidelines:

• Quick Win Sprint: 4-8 hours, targets easy P0/P1 items
• Standard Sprint: 16-24 hours, tackles systematic issues
• Deep Dive Sprint: 40+ hours, major architectural refactoring

Phase 4: Validation

After each sprint, run full validation:

npm run lint && npm run type-check && npm test

Regression Checklist:

• All existing tests pass
• No new lint warnings introduced
• No new TypeScript errors
• Build succeeds
• Application runs correctly

Metric Targets Reference

Output Format

When reporting assessment results, use this format:

## Code Quality Assessment - [Date]

### Summary
| Metric | Current | Target | Status |
|--------|---------|--------|--------|
| Lint Errors | X | 0 | ✅/❌ |
| Lint Warnings | X | 0 | ✅/❌ |
| TypeScript Errors | X | 0 | ✅/❌ |
| Test Coverage | X% | 80% | ✅/❌ |
| Code Duplication | X% | <2% | ✅/❌ |
| `any` Types | X | <50 | ✅/❌ |
| Large Files | X | 0 | ✅/❌ |

### Top Hotspots
1. [File/Issue]: [Description] - [Recommended action]
2. ...

### Recommended Sprint
[Sprint plan based on hotspots]

Related Files

• methodology.md - Refactoring patterns, sprint structure, prioritization, and lessons learned
• metrics-template.md - Tracking templates for baseline, sprint progress, and final validation

Source: prairieaster-ai/claude-code-skills — distributed by TomeVault.