"@controller is nil" error in ActionController::TestCase

[sunaku]

When using context() inside an ActionController::TestCase, I get the following error:

RuntimeError: @controller is nil: make sure you set it in your test's setup method.

Here is an example of what my test file looks like:

class ExamplesControllerTest < ActionController::TestCase
  context "index action" do
    should "return a list of examples" do
      get :index, :format => :json
      assert_response :success
    end
  end
end

The error is happening because context() creates a new Test::Unit::TestCase derived class whose name does not contain "ExamplesController", and so Rails becomes confused when it tries to automatically set @controller inside of the context() body.

Thanks for your consideration.

A workaround / solution is to assign @controller an instance of the controller you're testing in a block passed to setup().

[retr0h]

Is this gem so awesome, that no one maintains it anymore?

[sunaku]

It is indeed disheartening, @retr0h. There is always opportunity for improvement / increasing popularity!

[sunaku]

I wrote the following monkeypatch to automate @robgleeson's suggestion of setting @controller as a workaround for the problem:

class ActionController::TestCase
  def self.context *args, &block
    super *args do
      setup do
        # establish the rails controller being tested
        # https://github.com/citrusbyte/contest/issues/5#issuecomment-677003
        ancestors = self.class.ancestors
        test_case = ancestors[ancestors.index(ActionController::TestCase) - 1]
        @controller = test_case.controller_class.new
      end
      class_eval &block
    end
  end
end

Put that in your test/test_helper.rb and things will Just Work. Cheers.