Single Responsibility

singleResponsiblity.js

// Bad Case
class Staff {
  constructor(staff) {
    this.staff = staff;
  }

  registerStaff(staff) {
    if (this.validateUser(staff)) {
      return `${staff} has been created`;
    }
    return 'Error occured';
  }

  validateStaff(sfaff) {
    // mock validation
    if (staff) {
      return `${staff} validated`;
    }
    return `Sorry ${staff} could not validate user`;
  }
}


// good

class ValidateUser {
	constructor(user) {
		this.user = user;
	}

	validate(user) {
		if (user) {
			return `${user} validated`;
		}
		return `Sorry could not validate user`;
	}
}

class RegisterStaff {
  constructor(staff) {
    this.staff = staff;
    this.validator = new ValidateStaff(staff);
  }

  createStaff(staff) {
    if (this.validator.validate(staff)) {
      return `${staff} has been created`;
    }
    return 'Error occured';
  }
}