require-interface-prefix.md

require-interface-prefix

Enforce that TypeScript interface names start with I (capital letter) followed by an uppercase character.

Rule Details

Property	Value
Type	suggestion
Fixable	No
Recommended	warn
Strict	error

Rationale

Prefixing interface names with I makes it immediately clear in code that a type is an interface rather than a class or type alias. This convention improves readability, especially in large codebases where interfaces are heavily used.

Examples

✅ Correct

interface IUser {
  name: string;
  email: string;
}

interface IRepository<T> {
  findById(id: string): Promise<T>;
}

❌ Incorrect

interface User {
  name: string;
}

interface userProfile {
  age: number;
}

Configuration

This rule has no options. Enable it in your ESLint config:

'zero-tolerance/require-interface-prefix': 'error'