Email.ts

export class Email extends String {

  private static readonly PATTERN =
    /^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$/;

  constructor(value: any) {
    if (typeof value !== 'string') {
      throw new TypeError(`Email: expected string, got ${value.constructor}`);
    }

    const normalized = value.trim().toLowerCase();

    if (!Email.PATTERN.test(normalized)) {
      throw new TypeError(`Email: invalid address "${value}"`);
    }

    super(value)
  }

  get local(): string {
    return this.split('@')[0];
  }

  get domain(): string {
    return this.split('@')[1];
  }

  equals(other: Email): boolean {
    return this.toString() === other.toString();
  }

  static isValid(value: unknown): boolean {
    try {
      new Email(value as string);
      return true;
    } catch {
      return false;
    }
  }
}