TypeScript Best Practices in Production
Learn the best practices for writing clean and maintainable TypeScript code.
Use Strict TypeScript Configuration
Enable strict mode in tsconfig.json for better type safety
{
"compilerOptions": {
"strict": true,
"noImplicitAny": true,
"strictNullChecks": true
}
}This ensures better type checking and catches potential errors early in development.
Proper Interface and Type Usage
Define clear interfaces for objects and use types for unions/intersections
interface User {
id: number;
name: string;
email: string;
role: 'admin' | 'user';
}
type ApiResponse<T> = {
data: T;
status: number;
message: string;
};Interfaces provide clear contracts for objects, while types are great for complex type compositions.
Avoid Type 'any'
Use specific types instead of 'any' to maintain type safety
// Bad
function processData(data: any): any {
return data.value;
}
// Good
interface DataType {
value: string;
}
function processData(data: DataType): string {
return data.value;
}Using 'any' defeats the purpose of TypeScript's type checking system.
Utilize Generics
Use generics for reusable, type-safe components and functions
function getFirstElement<T>(arr: T[]): T | undefined {
return arr[0];
}
// Usage
const numbers = getFirstElement([1, 2, 3]); // type: number
const strings = getFirstElement(['a', 'b']); // type: stringGenerics provide type safety while maintaining code reusability.
Common Pitfalls to Avoid
Type Assertions Overuse
Avoid excessive use of type assertions (as Type). Instead, use proper type declarations and let TypeScript infer types when possible.
const userInput = event.target as HTMLInputElement; // Use sparinglyIgnoring Null/Undefined
Always handle potential null/undefined values explicitly
function getName(user: User | null): string { return user?.name ?? 'Unknown'; }