```ruby
# frozen_string_literal: true
module Messaging
  private

  def assert_message_sent(text)
    assert_css_selector '.bubble', text: text
    assert_content 'Mensaje enviado'
  end

  def send_message(params)
    subject = params[:subject]

    fill_in('subject', with: subject) if subject
    fill_in 'body', with: params[:body]
    click_button 'Enviar'
  end
end
```

Use keyword arguments for readability
user
```ruby
# frozen_string_literal: true
module Messaging
  private

  def assert_message_sent(text)
    assert_css_selector '.bubble', text: text
    assert_content 'Mensaje enviado'
  end

  def send_message(body: nil, subject: nil)
    fill_in('subject', with: subject) if subject
    fill_in 'body', with: body
    click_button 'Enviar'
  end
end
```
assistant