TypeScript Best Practices for Modern Web Development

TypeScript has become the de facto standard for building large-scale web applications. Let's explore some best practices to write better TypeScript code.

Type Definitions

Use Explicit Types

// Good
const user: User = { id: 1, name: "John" };

// Avoid
const user = { id: 1, name: "John" };

Leverage Type Inference

// Good
const numbers = [1, 2, 3]; // TypeScript infers number[]

// Avoid
const numbers: number[] = [1, 2, 3];

Interface vs Type

Use Interfaces for Objects

interface User {
  id: number;
  name: string;
  email: string;
}

Use Types for Unions and Intersections

type Status = "pending" | "success" | "error";
type ExtendedUser = User & { role: string };

Generics

Write Reusable Components

function createArray<T>(length: number, value: T): T[] {
  return Array(length).fill(value);
}

Error Handling

Use Custom Error Types

class ValidationError extends Error {
  constructor(message: string) {
    super(message);
    this.name = "ValidationError";
  }
}

Conclusion

Following these best practices will help you write more maintainable and type-safe TypeScript code. Remember to:

• Use explicit types when necessary
• Leverage type inference when possible
• Choose between interfaces and types appropriately
• Use generics for reusable code
• Implement proper error handling