Rails Anonymous Controller Testing

I sometimes want to test an abstract controller, a controller concern, a view, or a helper method.

This might be useful for you if you're working on a Rails engine or if you're editing your ApplicationController.

This only works with Minitest, specifically for tests that inherit from ActionDispatch::IntegrationTest.

Usage

class MyControllerTest < ActionDispatch::IntegrationTest
  # 1. Call the `controller` method. You must specify the base controller to
  #    inherit from. It'll set up routes with `resources :anonymous`.
  controller(ApplicationController) do
    def index
    end

    def show
      render plain: params[:id]
    end
  end

  # 2. Optionally, set views. There are some caveats, see below
  views["layouts/application.html.erb"] = <<~HTML
    <h1>My anonymous test</h1>
    <%= yield %>
  HTML

  views["index.html.erb"] = <<~HTML
    <h2>Hi</h2>
  HTML

  # 3. Test like it's a regular controller in your application
  def test_index
    get "/anonymous"
    assert_select "h1", "My anonymous test"
    assert_select "h2", "Hi"
  end

  def test_show
    get "/anonymous/1234"
    assert_equal "1234", response.body
  end
end

You can also specify the routes too, but you need to namespace the controller to the name of the test class.

class MyControllerTest < ActionDispatch::IntegrationTest
  routes = -> { get "custom", to: "my_controller_test/anonymous#custom" }
  controller(ApplicationController, routes: routes) do
    def custom
    end
  end
end

Views

A few things to note about views:

• Views are generated only once and cached. This is determined by the MD5 hash of the test file you defined the controller. You can disable caching by calling disable_anonymous_view_cache! in your Rails test. The view cache is located in tmp/anonymous_controller_views.
• If you override the layout for your anonymous controller, you'll also override the layout for your other controllers. This is because this library uses prepend_view_path, so the views defined in the test take precedence over the other view directories.

Installation

Add this line to your application's Gemfile:

gem "rails_anonymous_controller_testing", group: :test

And then execute:

$ bundle

Contributing

Contributions very welcome. Please give me edit access to your branch for a faster turnaround.

License

The gem is available as open source under the terms of the MIT License.