Password field check with JS

Question

I made a filter to check if the password field contained at least 6 characters, but now I need to return an error message if you do not have it.

I tried using map, because the application already contained a generic error, but I need one for this specific type of error

My password field is this:

.mdl-textfield.mdl-js-textfield.mdl-textfield--floating-label
            input#newPassword.mdl-textfield__input(type="password" data-validation="password-register" name="newPassword")
            label.mdl-textfield__label(for="newPassword")= __('reset-password.form.new-password')
            span.mdl-textfield__error

  event.preventDefault();
  const invalidFields = getInvalidFields(event.target, {
    validations: {
      'password-register': {
        passwordPolicy: element => element.value.length >= 6,
        message: 'A senha deve ter ao menos 6 caracteres.',
      },
    },
  });

  if (invalidFields.length) {
    showErrorMessage(invalidFields);
    return;
  }

  Array.from(form.elements)
    .filter(element => element instanceof HTMLInputElement)
    .filter(input => (
      !input.value
      || (validations[input.dataset.validation]
        && !validations[input.dataset.validation].passwordPolicy(input))
    ))
);

export const showErrorMessage = invalidFields => (
  invalidFields.forEach((input) => {
    input.parentElement.lastElementChild.innerHTML = 'Campo obrigatório';
    input.passwordPolicy.innerHTML = 'Errrooooooooow'; //não funciona
    input.parentElement.classList.add('is-invalid');
  })
);