Question

This question has probably been asked a dozen times on Stack Overflow (e.g. (1), (2), (3), (4), (5)) but every time the answer seems to be different and none of them have helped me. I’m working on a Rails Engine and I’m finding that Rspec2 gets route errors, but I can reach the routes in the browser. Here’s the situation:

• In the engine’s routes.rb:

  resources :mw_interactives, :controller => 'mw_interactives', :constraints => { :id => /\d+/ }, :except => :show
  
  # This is so we can build the InteractiveItem at the same time as the Interactive
  resources :pages, :controller => 'interactive_pages', :constraints => { :id => /\d+/ }, :only => [:show] do
    resources :mw_interactives, :controller => 'mw_interactives', :constraints => { :id => /\d+/ }, :except => :show
  end
  

• Excerpted output of rake routes:

       new_mw_interactive GET    /mw_interactives/new(.:format)                              lightweight/mw_interactives#new {:id=>/\d+/}
                          ...
  new_page_mw_interactive GET    /pages/:page_id/mw_interactives/new(.:format)               lightweight/mw_interactives#new {:id=>/\d+/, :page_id=>/\d+/}
  

• And my test, from one of the controller specs (describe Lightweight::MwInteractivesController do):

  it 'shows a form for a new interactive' do
    get :new
  end
  

…which gets this result:

Failure/Error: get :new
ActionController::RoutingError:
  No route matches {:controller=>"lightweight/mw_interactives", :action=>"new"}

…and yet when I go to that route in the browser, it works exactly as intended.

What am I missing here?

ETA: To clarify a point Andreas raises: this is a Rails Engine, so rspec runs in a dummy application which includes the engine’s routes in a namespace:

 mount Lightweight::Engine => "/lightweight"

…so the routes shown in rake routes are prefaced with /lightweight/. That’s why the route shown in the Rspec error doesn’t seem to match what’s in rake routes. But it does make the debugging an extra step wonkier.

ETA2: Answering Ryan Clark’s comment, this is the action I’m testing:

 module Lightweight
   class MwInteractivesController < ApplicationController
     def new
       create
     end

…and that’s it.

Answer 1

I found a workaround for this. Right at the top of the spec, I added this code:

render_views
before do
  # work around bug in routing testing
  @routes = Lightweight::Engine.routes
end

…and now the spec runs without the routing error. But I don’t know why this works, so if someone can post an answer which explains it, I’ll accept that.