stitch-ui/src/auth/validation.js

const validateUserPass = ({ email, password, confirmPassword }) => {
  if (email.length === 0) {
    return "username must not be empty";
  }
  if (password.length === 0) {
    return "password must not be empty";
  }

  if (password !== confirmPassword) {
    return "passwords must match";
  }
  return null;
};

export default validateUserPass;