Email

class Email {
  private address: string;
 
  constructor(address: string) {
    if (!this.isValidEmail(address)) {
      throw new Error(
        "Invalid email address. Please provide a valid email address."
      );
    }
    this.address = address;
  }
 
  equals(other: Email): boolean {
    return this.address === other.address;
  }
 
  toString(): string {
    return this.address;
  }
 
  private isValidEmail(email: string): boolean {
    // This is a basic email validation. You can use a more comprehensive regular expression for production use.
    const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;
    return emailRegex.test(email);
  }
}
 
// Example usage:
const validEmail = new Email("john.doe@example.com");
const invalidEmail = new Email("invalid_email");
console.log(validEmail.toString()); // Output: "john.doe@example.com"
console.log(invalidEmail.toString()); // Throws an error for an invalid email

// Import the Email class (assuming it's in a separate file)
import { Email } from "./email";
 
describe("Email", () => {
  describe("constructor", () => {
    it("should create an Email instance with a valid email address", () => {
      expect(() => new Email("john.doe@example.com")).not.toThrow();
    });
 
    it("should throw an error for an invalid email address", () => {
      expect(() => new Email("invalid_email")).toThrow();
    });
  });
 
  describe("equals", () => {
    it("should return true when comparing two Email instances with the same address", () => {
      const email1 = new Email("john.doe@example.com");
      const email2 = new Email("john.doe@example.com");
      expect(email1.equals(email2)).toBe(true);
    });
 
    it("should return false when comparing two Email instances with different addresses", () => {
      const email1 = new Email("john.doe@example.com");
      const email2 = new Email("jane.smith@example.com");
      expect(email1.equals(email2)).toBe(false);
    });
  });
 
  describe("toString", () => {
    it("should return the string representation of the Email", () => {
      const email = new Email("john.doe@example.com");
      expect(email.toString()).toBe("john.doe@example.com");
    });
  });
});