```ruby
require 'test_helper'

module ActionController
  class Base
    def render_to_string opts={}
      opts.to_s
    end
  end
end

class PdfHelperTest < ActionController::TestCase
  def setup
    @ac = ActionController::Base.new
  end

  def teardown
    @ac=nil
  end

  test "should prerender header and footer :template options" do
    options = @ac.send( :prerender_header_and_footer,
                        :header => {:html => { :template => 'hf.html.erb'}});
    assert !options[:header][:html].has_key?(:template)
    assert_match /^file:\/\/.*wicked_pdf.*\.html/, options[:header][:html][:url]
  end
end
```

Fix test checking for tempfile name
user
```ruby
require 'test_helper'

module ActionController
  class Base
    def render_to_string opts={}
      opts.to_s
    end
  end
end

class PdfHelperTest < ActionController::TestCase
  def setup
    @ac = ActionController::Base.new
  end

  def teardown
    @ac=nil
  end

  test "should prerender header and footer :template options" do
    options = @ac.send( :prerender_header_and_footer,
                        :header => {:html => { :template => 'hf.html.erb'}});
    assert !options[:header][:html].has_key?(:template)
    assert_match /^file:\/\/.*wicked_header_pdf.*\.html/, options[:header][:html][:url]
  end
end
```
assistant