Atwam

I do stuff, and write about it

Using Rspec with inherited_resources helpers and inherited views

I have updated a rails app I have been working on recently to a more recent version of rails 3.2, and all my tests where failing. Finally managed to have that working, figured I’d show how.

Mocking inherited_resources helpers in views specs.

I know I shouldn’t be using inherited_resources anymore (see here and here) but I want to release my app before I change everything to use responders.

So, my tests where failing because I was using the resource, collection and resource_class helpers from some views I was using. So first my tests are failing because resource_class isn’t available in my views. I would have thought that the controller helpers were available in the views, but they aren’t. The solution is easy. Let’s add the following to our spec/support directory :

spec/support/view_resource_macros.rb
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module ViewResourceMacros
  def has_resource(name, &block)
    before do
      # Creates the resource
      @resource ||= yield
      # Assign to the symbol we wanted, so it's available in the view
      assign(name, @resource)
      # Assigns to @name so that we can use that in our assertions
      instance_variable_set("@#{name}", @resource)

      # If we pass an array, it's for stubing a collection, if not it's for stubbing a single object
      if @resource.is_a?(Array)
        view.stub(:collection) { @resource }
        view.stub(:resource_class) {@resource.first.class}
      else
        view.stub(:resource) {@resource}
        view.stub(:resource_class) {@resource.class}
      end
    end
  end
end

RSpec.configure do |config|
  config.extend ViewResourceMacros, :type => :view
end

And see how to transform our old (failing) test :

spec/views/cars/edit.html.haml_spec.rb
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require 'spec_helper'

describe "cars/edit.html.haml" do
  before(:each) do
    assign(:car, @car = Factory.create(:car))
  end

  it "renders the edit view" do
    render
    rendered.should contain(@car.name)
  end
end

becomes :

spec/views/cars/edit.html.haml_spec.rb
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require 'spec_helper'

describe "cars/edit.html.haml" do
  has_resource(:car) { Factory.create(:car) }

  it "renders the edit view" do
    render
    rendered.should contain(@car.name)
  end
end

Using shared inherited partial in our views specs

Rails 3.1+ offers views inheritance, so I changed my code to have the following :

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class BaseController

end

class CarsController < BaseController
  inherit_resources
end

class PlanesController < BaseController
  inherit_resources
end

Then I just created a base/new.html.haml and a base/edit.html.haml views, to use the views inheritance.

base/new.html.haml
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%h1 Create #{resource_class.model_name.human}
= render :partial => "form"
base/edit.html.haml
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%h1 Edit #{resource}
= render :partial => "form"

And I have two _form.html.haml partials, one for each controller. Now the next issue is that our edit and new views are shared, but we still want to test the _form.html.haml partial.

spec/views/cars/_form.html.haml_spec.rb
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require 'spec_helper

describe "cars/_form.html.haml" do
  {
    new: -> { Car.new }
    edit: -> { Factory.create(:car) }
  }.each do |name, block|
    context "when called in ##{name}" do
      has_resource(name, block)

      it "renders the form" do
        render
        rendered.should have_selector("form")
      end
    end
  end
end

Shared partial

Finally, when testing for example cars/index.html.haml which uses a partial toolbar.html.haml that actually exists in base views, the following lines are necessary :

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before do
  views.lookup_context.prefixes << "base"
end

This was raised as an issue to the rails team, but they commented (rightly I think) that the inheritance is related to the controller, not the views, so the test case shouldn’t know about it and you’ll have to declare it manually using the lines above.

Now let’s go back and make these tests green again.

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