TypeScript is a powerful language that brings static typing to JavaScript. For large-scale applications, following best practices is essential.
1. Use Advanced Types
TypeScript's type system is powerful. Leverage:
// Generic types for reusable components
type Props<T> = {
data: T[]
isLoading: boolean
error?: Error
}
// Conditional types
type ApiResponse<T> = {
success: true
data: T
} | {
success: false
error: string
}2. Organize by Feature
// types/auth/index.ts
export interface User {
id: string
email: string
}
// types/auth/permissions.ts
export interface Permission {
role: 'admin' | 'user'
}3. Use Type Guards
function isUser(value: unknown): value is User {
return (
typeof value === 'object' &&
value !== null &&
'id' in value &&
'email' in value
)
}4. Avoid any
// ❌ Avoid
function process(data: any) { }
// ✅ Use generics
function process<T>(data: T): T { }5. Leverage Utility Types
type Partial<T> = {
[P in keyof T]?: T[P]
}
type Required<T> = {
[P in keyof T]-?: T[P]
}6. Type Your API Responses
interface ApiResponse<T> {
data: T
message: string
timestamp: number
}Following these practices will help you maintain type safety and catch errors early in development.