[Rails] render_to_string in a controller fails under RSpec

I’m using render_to_string in a controller to send some JSON data with
an HTML fragment. Unfortunately, it seems that rspec-rails breaks that
by intercepting render and simply recording that a render was called.
Using rspec-rails and rspec versions 1.2.9, I’ve tracked it down to
lib/spec/rails/example/controller_example_group.rb:181 – since it’s
calling record_render, it returns a Fixnum, so instead of an HTML
fragment, I get “1”. I’ve confirmed that if I add a call to “super” on
the next line, it does what I want. Obviously that would be bad for
other reasons, though.

Is there a workaround for this? Is there a better way to get an HTML
fragment included in the JSON? Using an RJS template won’t work, since
it wraps my JSON object in an exception handling block.

For reference, here’s the controller action that calls
render_to_string:

def changed
unless params[:since]
render :status => :bad_request
return
end
respond_to do |format|
format.js do
@changed = Event.changed_since(params[:since]).collect do |
event|
{
:id => dom_id(event),
:sidebar_html => render_to_string(:partial =>
“history_item”, :object => event)
}
end
render :json => @changed
end
end
end

And here is the relevant part of the controller spec:

  it "should return the sidebar HTML for the event" do
    get :changed, :since => @time
    json = JSON.parse(response.body)
    json.should have(1).event
    response.body = json.first["sidebar_html"]
    response.should include_text("TestApp r1234")
  end

On Thu, Nov 5, 2009 at 5:23 PM, Joel Y. [email protected] wrote:

Is there a workaround for this? Is there a better way to get an HTML
end
render :json => @changed
response.body = json.first[“sidebar_html”]
response.should include_text(“TestApp r1234”)
end

http://rspec.info/rails/writing/controllers.html

For any case in which you want the controller to render views, you can
say
integrate_views.

HTH,
David