Classes

• Selector: class
• Required: PascalCase

Why This Rule

PascalCase for classes is a universal convention across almost all programming languages (Java, C#, Python, Ruby, etc.). This convention:

• Instantly distinguishes types from values at a glance
• Matches constructor usage: new UserService() reads naturally
• Aligns with community standards: 99% of TypeScript codebases follow this

Benefits:

• When you see UserService, you immediately know it's a class or type.
• When you see userService, you know it's an instance or variable.

This visual distinction reduces cognitive load and prevents naming conflicts.

References:

• TypeScript Handbook - Classes
• Airbnb JavaScript Style Guide - PascalCase for Classes

✅ Good

class UserService {} // WHY: PascalCase - clearly a class/type
class HTTPClient {} // WHY: PascalCase with acronym – keeps class semantics clear

❌ Bad

class userService {} // WHY: camelCase for a class confuses instances with types
class user_service {} // WHY: snake_case is not appropriate for class names
class HTTPclient {} // WHY: Incorrect casing – should be PascalCase