With RSpec2 and Rails3.0.4, how to test your generic controller like admin_controller.rb from XML

What's the problem

I wanna test a before filter that render errors in XML and JSON if failing. When testing it from a classic controller it works fine, when testing from the ApplicationController directly it fails.

A light version of the code

specs/controller/admin_controller_spec.rb

require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')

describe AdminController do
  controller(AdminController) do
    def index
      render :text => 'ok'
    end
  end

  it "should include errors properly formated" do
    get :index, :format => 'xml'
    response.body.should == "block"
  end
end

app/controller/admin_controller.rb

class AdminController < ApplicationController
  before_filter :block_something

  protected

    def block_something
      respond_to do |wants|
        wants.xml {
          render :text => 'block' 
        }
      end
    end
end

Error from tests

Failure/Error: get :index, :format => format
  TypeError:
    can't convert nil into String

Update, with backtrace : thanks Ryan Bigg for the recommendation

It gives different controller and filter names than the example above. The app use admin_controller.rb and block_suspended filter.

 # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:61:in `<<'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:61:in `build_path'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:54:in `find_templates'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:20:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:39:in `cached'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/template/resolver.rb:19:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:21:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:20:in `each'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:20:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:21:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:20:in `each'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:20:in `find_all'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/paths.rb:28:in `exists?'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_view/lookup_context.rb:90:in `template_exists?'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/view_paths.rb:11:in `__send__'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/view_paths.rb:11:in `template_exists?'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/layouts.rb:272:in `_layout'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/layouts.rb:345:in `_default_layout'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/layouts.rb:323:in `_layout_for_option'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/layouts.rb:290:in `_normalize_options'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/rendering.rb:41:in `_normalize_options'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/compatibility.rb:50:in `_normalize_options'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/rendering.rb:101:in `render_to_string'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/rendering.rb:93:in `render'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/rendering.rb:17:in `render'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:40:in `render_without_wicked_pdf'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/core_ext/benchmark.rb:5:in `ms'
     # /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/benchmark.rb:308:in `realtime'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/core_ext/benchmark.rb:5:in `ms'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:40:in `render_without_wicked_pdf'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:78:in `cleanup_view_runtime'
     # /Library/Ruby/Gems/1.8/gems/activerecord-3.0.4/lib/active_record/railties/controller_runtime.rb:15:in `cleanup_view_runtime'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:39:in `render_without_wicked_pdf'
     # ./app/controllers/admin_controller.rb:36:in `block_suspended'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/mime_responds.rb:192:in `call'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/mime_responds.rb:192:in `respond_to'
     # ./app/controllers/admin_controller.rb:33:in `block_suspended'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/callbacks.rb:466:in `_run__1727617933__process_action__199225275__callbacks'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/callbacks.rb:409:in `send'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/callbacks.rb:409:in `_run_process_action_callbacks'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/callbacks.rb:93:in `send'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/callbacks.rb:93:in `run_callbacks'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/callbacks.rb:17:in `process_action'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications.rb:52:in `instrument'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications/instrumenter.rb:21:in `instrument'
     # /Library/Ruby/Gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications.rb:52:in `instrument'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/instrumentation.rb:29:in `process_action'
     # /Library/Ruby/开发者_运维百科Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/rescue.rb:17:in `process_action'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/base.rb:119:in `process'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/abstract_controller/rendering.rb:41:in `process'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/metal/testing.rb:12:in `process_with_new_base_test'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/test_case.rb:412:in `process'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/test_case.rb:47:in `process'
     # /Library/Ruby/Gems/1.8/gems/actionpack-3.0.4/lib/action_controller/test_case.rb:350:in `get'
     # ./spec/controllers/admin_controller_spec.rb:272
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:29:in `instance_eval'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:29:in `run_in'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:64:in `run_all'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:64:in `each'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:64:in `run_all'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/hooks.rb:110:in `run_hook'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:191:in `eval_before_eachs'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:191:in `each'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:191:in `eval_before_eachs'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:144:in `run_before_each'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:48:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:106:in `with_around_hooks'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:46:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:99:in `with_pending_capture'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:98:in `catch'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:98:in `with_pending_capture'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example.rb:45:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:262:in `run_examples'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:258:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:258:in `run_examples'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:232:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/example_group.rb:233:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/command_line.rb:27:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/command_line.rb:27:in `map'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/command_line.rb:27:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/reporter.rb:12:in `report'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/command_line.rb:24:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/runner.rb:55:in `run_in_process'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/runner.rb:46:in `run'
     # /Library/Ruby/Gems/1.8/gems/rspec-core-2.5.1/lib/rspec/core/runner.rb:10:in `autorun'
     # /usr/bin/rspec:19

Any thought on why this appends? If not the right way to test it, how to test such behavior?

---

I've now upgraded to ruby 1.9.2 and all specs passes without any changes required.

Looks like a limitation of Ruby 1.8.7 that would need extra workarounds.