ruby on rails - Getting an ActionController::UnknownFormat, rspec testing when creating new object -

recently moved rails 4 , getting errors wasn't getting before. i'm trying test form i'm making using capybara/rspec.

when click button on form, error is:

failure/error: find(".submit.button").click      actioncontroller::unknownformat:        actioncontroller::unknownformat      # ./app/controllers/office_listings_controller.rb:32:in `create'      # ./spec/features/office_listings_spec.rb:78:in `block (3 levels) in <top (required)>' 

it points controller looks like:

def create     selected_amenities = params[:amenities] || [] # empty list if no amenities checked     @office_listing = officelisting.new(params[:office_listing])     @office_listing.broker = current_broker     p current_broker     @office_listing.neighborhood = neighborhood.find(params[:neighborhood_id])     p @office_listing.neighborhood     if @office_listing && @office_listing.save!       @path = city_neighborhood_office_listing_path(@office_listing, :city_id => @office_listing.neighborhood.city.id, :neighborhood_id => @office_listing.neighborhood.id)       create_amenities(@office_listing, selected_amenities)       respond_to |format|         format.js       end     else       @failure = "unable create office :-("       respond_to |format|         format.js       end     end   end 

and doesn't format.js line though have create.js.erb file being rendered when run page.

don't understand why actual page running test failing.

any thoughts appreciated!!

i had similar problem:

post :duplicate, id: patient.media.first.id 

produced same error:

failure/error: post :duplicate, id: patient.media.first.id actioncontroller::unknownformat: actioncontroller::unknownformat 

i fixed adding format post call:

post :duplicate, id: patient.media.first.id, format: :js