# Best Practices

> Language-specific best practices, code quality standards, and framework detection rules. Use when executing refactoring workflows, applying code quality rules, detecting frameworks, or checking language-specific patterns for TypeScript, Python, Go, Swift, or React.

- Skill: `fradser/best-practices` (Agent Skill, multi-file: 111 files)
- Install (CLI): `npx skillmds@latest add fradser/best-practices`
- Raw SKILL.md: https://api.skillmd.com/api/skills/fradser/best-practices/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: FradSer (https://skillmd.com/u/fradser)
- Updated: 2026-08-19
- Page: https://skillmd.com/skills/fradser/best-practices

---


# Best Practices

## Language References

Each file extension maps to a specific reference:

- `.ts`, `.js` — `references/typescript.md`
- `.tsx`, `.jsx` — `references/typescript.md` + `references/react/react.md`
- `.py` — `references/python.md` + `references/python/INDEX.md`
- `.go` — `references/go.md`
- `.swift` — `references/swift.md`

Universal principles are in `references/universal.md`.

## Next.js/React References

For Next.js projects, the `references/react/` directory provides:

1. `references/react/rules/INDEX.md` — pattern index by impact level
2. `references/react/rules/_sections.md` — priorities and categories
3. Specific rule files matching observed patterns

## Rule Application

- Framework-specific rules (e.g., Next.js) apply only when that framework is detected
- **CRITICAL** rules have highest priority: waterfalls, bundle size, hydration
- All refactoring MUST preserve behavior and public interfaces

## Code Quality Standards

- **Comments**: Only for complex business logic; code-restating comments are unnecessary
- **Error Handling**: Try-catch only where recoverable; no defensive checks in trusted paths
- **Type Safety**: No `any`; proper types or `unknown` with guards are required
- **Style**: Existing code style and CLAUDE.md conventions take precedence
- **Cleanup**: Unused imports, variables, functions, and types are removed
- **No compat hacks**: Unused `_vars` and re-exports of deleted code are deleted
- **Renaming**: Descriptive names are preferred over marking as unused
- **Dead code**: Dead code is deleted, never commented out
- **File Organization**: Single Responsibility applies at file level; files with multiple concerns are candidates for splitting (see `references/universal.md`)