typescript

Instruction file imported from creacher-creolio/expo-template (.cursor/rules/typescript.mdc). Copyright stays with the author.

description: Typescript globs: .ts,.tsx alwaysApply: false

Type Definitions

• Define interfaces/types in separate files when reused across components
• Use explicit type annotations for function parameters and returns
• Prefer interfaces for objects that can be extended
• Use union types for values with a finite set of options
• Create dedicated type files (types.ts) for shared types

Best Practices

• Avoid any and unknown types unless absolutely necessary
• Use generics for reusable components and utilities
• Implement proper discriminated unions for complex state
• Add index signatures for dynamic object properties
• Implement proper error typing for try/catch blocks
• Use strict null checks and non-null assertion with caution
• Leverage TypeScript utility types (Partial, Pick, Omit, etc.)
• Use optional chaining (?.) and nullish coalescing (??)
• Use type guards for narrowing types (is, as, in)

Project Setup

• Ensure tsconfig.json has strict mode enabled
• Configure path aliases in tsconfig.json for clean imports
• Keep type definitions in sync with backend API contracts
• Utilize React Native specific type definitions