typescript

name	typescript
description	TypeScript guidelines. Use when editing or reviewing `**/*.ts` and `**/*.tsx` files.
license	MIT
user-invocable	false
metadata	{"author":"quisi.do"}

TypeScript guidelines

Conventions

• Follow functional programming principles where possible.

• Prefer immutable data (const, readonly).

• Support exactOptionalPropertyTypes by explicitly including | undefined in optional property definitions, e.g. readonly foo?: string | undefined.

• Use interfaces for data structures and type definitions.

• When a function only takes one parameter and that parameter is an untyped object, name that parameter's interface Options.

  interface Options { /* ... */ }
  export default function myFn({ /* ... */ }: Options): void {}
  

Constraints

• Do not prefix interfaces with I (e.g., use User instead of IUser) unless the name is already taken. For example, if a React component is already named User, then fallback to IUser for the interface.