# Typescript > TypeScript code style and optimization guidelines. Use when writing TypeScript code (.ts, .tsx, .mts files), reviewing code quality, or implementing type-safe patterns. Triggers on TypeScript development, type safety questions, or code style discussions. Use when this capability is needed. - Skill: `tomevault-io/typescript-5` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/typescript-5` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/typescript-5/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/typescript-5 --- # TypeScript Code Style Guide ## Types and Type Safety - Avoid explicit type annotations when TypeScript can infer - Avoid implicitly `any`; explicitly type when necessary - Use accurate types: prefer `Record` over `object` or `any` - Prefer `interface` for object shapes (e.g., React props); use `type` for unions/intersections - Prefer `as const satisfies XyzInterface` over plain `as const` - Prefer `@ts-expect-error` over `@ts-ignore` over `as any` - Avoid meaningless null/undefined parameters; design strict function contracts ## Async Patterns - Prefer `async`/`await` over callbacks or `.then()` chains - Prefer async APIs over sync ones (avoid `*Sync`) - Use promise-based variants: `import { readFile } from 'fs/promises'` - Use `Promise.all`, `Promise.race` for concurrent operations where safe ## Code Structure - Prefer object destructuring - Use consistent, descriptive naming; avoid obscure abbreviations - Replace magic numbers/strings with well-named constants - Defer formatting to tooling ## Performance - Prefer `for…of` loops over index-based `for` loops - Reuse existing utils in `packages/utils` or installed npm packages - Query only required columns from database ## Time Consistency - Assign `Date.now()` to a constant once and reuse for consistency ## Logging - Never log user private information (API keys, etc.) - Don't use `import { log } from 'debug'` directly (logs to console) - Use `console.error` in catch blocks instead of debug package ## Code Quality - No `any` types unless absolutely necessary - Check node_modules for external API type definitions instead of guessing - **NEVER use inline imports** - no `await import("./foo.js")`, no `import("pkg").Type` in type positions, no dynamic imports for types. Always use standard top-level imports. - NEVER remove or downgrade code to fix type errors from outdated dependencies; upgrade the dependency instead - Always ask before removing functionality or code that appears to be intentional - Never hardcode key checks with, eg. `matchesKey(keyData, "ctrl+x")`. All keybindings must be configurable. Add default to matching object (`DEFAULT_EDITOR_KEYBINDINGS` or `DEFAULT_APP_KEYBINDINGS`) --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/wibus-wee) — claim your Tome and manage your conversions.