title: Custom FormBuilder super class is a SafeBuffer. What am I missing?
body: <p>So, I have a custom form builder. It works except for when I want to override superclass methods.</p>
  
  <p>When I do the following:</p>
  
  <pre><code>class MyFormBuilder &lt; ActionView::Helpers::FormBuilder
    def number_field(value, options = {})
      super.number_field(value, options)
    end
  end
  </code></pre>
  
  <p>and call </p>
  
  <pre><code>'f.number_field(:value)'
  </code></pre>
  
  <p>on my form, I get the following error:</p>
  
  <pre><code>undefined method `number_field' for #&lt;ActiveSupport::SafeBuffer:0x007f9a44b762f0&gt;
  </code></pre>
  
  <p>I have called</p>
  
  <pre><code>raise "class: #{super.class}"
  </code></pre>
  
  <p>inside number field and I get:</p>
  
  <p>class: ActiveSupport::SafeBuffer</p>
  
  <p>So the error is arising from my overridden method. Other methods that don't call super class methods work fine in my form builder. Any idea what I'm doing wrong?</p>