Clean Code Guidelines in TypeScript

🛠 General Principles

• Readability over Cleverness: Write code that’s easy to understand, not just functional.
• Single Responsibility: Each function, class, or module should have one clear purpose.
• Avoid Duplication: Use abstractions to eliminate repetitive code (DRY principle).
• Type Safety: Leverage TypeScript’s strong type system to catch errors early.

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✅ TypeScript-Specific Best Practices

1. Prefer Interfaces over Types

Use interface for describing data structures whenever possible:

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

2. Use Enum for Constant Values

enum UserRole {
  Admin,
  User,
  Guest,
}

3. Always Type Function Parameters and Return Values

function getUserName(user: User): string {
  return user.name;
}

4. Avoid any Type

let data: unknown;

🧹 Clean Functions

1. Keep Functions Small

A function should do only one thing.

function calculateDiscount(price: number, discount: number): number {
  return price * (1 - discount);
}

2. Use Descriptive Names

Avoid cryptic variable names.

// Bad
function x(y: number): number {
  return y * 2;
}

// Good
function doubleValue(value: number): number {
  return value * 2;
}

3. Error Handling

Use try-catch for Error-Prone Operations

try {
  const data = await fetchData();
} catch (error) {
  console.error("Error fetching data", error);
}