# Code Quality > Code quality guidelines. ALWAYS use skill for ANY code changes. Use when this capability is needed. - Skill: `tomevault-io/code-quality-20` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/code-quality-20` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/code-quality-20/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/code-quality-20 --- # Code Quality Guidelines ## Don't write forgiving code - Don't permit multiple input formats - In TypeScript, this means avoiding Union Type (the `|` in types) - Use preconditions - Use schema libraries - Assert that inputs match expected formats - When expectations are violated, throw, don't log - Don't add defensive try/catch blocks - Usually we let exceptions propagate out - Don't keep legacy code paths as fallbacks - Remove old code instead of keeping it around for compatibility ## Naming Conventions - Don't use abbreviations or acronyms - Choose `number` instead of `num` and `greaterThan` instead of `gt` ## File Management - Prefer editing an existing file to creating a new one - Confirm with the user before creating any new markdown files ## Style - Emoji and unicode characters are welcome - Use them at the beginning of comments, commit messages, and in headers in docs --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/motlin) — claim your Tome and manage your conversions.