title: Use "error_messages" in Rails 3.2? (raises "undefined method" error)
body: <p>I am getting the following error in my Rails 3.2 functional tests:</p>
  
  <blockquote>
    <p>ActionView::Template::Error: undefined method `error_messages' for # 
    &lt;ActionView::Helpers::FormBuilder:0x007ff8ad00d3b0&gt;</p>
  </blockquote>
  
  <p>The view code that is creating the error:</p>
  
  <pre><code>&lt;%= form_for [@camp, @program] do |f| %&gt;
    &lt;%= f.error_messages %&gt; # problematic code
    &lt;%= f.label :name %&gt;
  &lt;% end %&gt;
  </code></pre>
  
  <p>Here is the code in my controller that is calling the above view code:</p>
  
  <pre><code>render :action =&gt; "edit", :status =&gt; :bad_request
  </code></pre>
  
  <p>And here is the test I am running:</p>
  
  <pre><code>test "update a program with a bad request" do
    put :update, 
      :id =&gt; programs(:traditional).to_param, 
      :program =&gt; {
        :min_age =&gt; "a" 
      },
      :camp_id =&gt; camps(123).uri
  
    assert_response :bad_request
  end
  </code></pre>
  
  <p>Does anyone have any insight into why this error is occurring in a Rails 3.2 app?</p>
  
  <p>Thanks!</p>