typescript-conventions

name	typescript-conventions
description	TypeScript coding conventions — imports, naming, module structure, error handling, and ESLint/Prettier integration
compatibility	>=1.4

TypeScript Conventions

Skill metadata: version "1.0"; license MIT; tags [typescript, eslint, prettier, conventions]; recommended tools [codebase, editFiles].

When to use

• Writing or reviewing TypeScript source files
• Enforcing TypeScript coding standards and module patterns

File scope

Applies to: **/*.ts, **/*.tsx, **/*.mts, **/*.cts

Conventions

• Use named exports for most modules. Reserve default exports for framework convention (Next.js pages, React lazy-loaded components).
• Import types with import type { ... } to keep runtime bundles clean.
• Use const by default. Use let only when reassignment is necessary. Never use var.
• Prefer interface for object shapes that may be extended. Use type for unions, intersections, and mapped types.
• Name interfaces and types in PascalCase. Name constants in SCREAMING_SNAKE_CASE only if they are truly compile-time constants.
• Use early returns to reduce nesting depth.
• Prefer async/await over raw Promise chains.
• Handle errors explicitly — never silently swallow rejections.
• Use unknown instead of any for values of uncertain type.
• Configure ESLint with @typescript-eslint/recommended-type-checked for maximum safety.
• Use Prettier or the editor's formatter for consistent formatting — do not debate style in reviews.
• Barrel files (index.ts re-exports) are acceptable for public API surfaces but should not re-export internal implementation details.