Question

I’ve ben struggling with this for a couple hours now. I am using Rack::Test to write API tests for my Rails 3.2 app.

Regardless of what I do, last_response has an empty body (well, specifically it has “{}”, so 2 characters).

Here are the tests:

describe "updating a product set with JSON" do
  def app
    ProductSetsController.action(:update)
  end

  let(:update_json) { ... }

  before do
    @product_set = FactoryGirl.build(:product_set)
  end
  it { @failures.should == 0 }

  it "should not increment the product set count" do
    expect { put :update, update_json }.to_not change(ProductSet, :count).by(1)
  end

  it "should increment the conditions count" do
    expect { put :update, update_json }.to change(@product_set.conditions, :count).by(2)
  end

  context "response should be valid" do
    before do
      put :update, update_json
    end
    subject { last_response }
    it { should be_ok }
  end
end

All these tests pass. But the body is empty.

The weird thing is that if I run the actual application the response body is definitely not empty. It has JSON about the updated product_set.

So I’m setting up the test incorrectly somehow. I bet I’m overlooking something really silly as this is my first time using Rack::Test. Any thoughts?

Just had a thought that I may not be setting the request headers correctly. I’m also using RABL for generation.

UPDATE:
The problem is indeed with RABL. Haven’t figured out a solution yet, but if I use:

respond_with(@product_set.update_attributes(get_properties(params)),
  file: 'app/views/product_sets/update.json.rabl', :handlers => [:rabl])

instead of:

respond_with(@product_set.update_attributes(get_properties(params)))

then it works in testing, whereas both work in development or production. Also I’ve confirmed that it’s not a Gemfile problem.

Answer 1

Found the answer. In short, make sure to use the keyword “render_views” at the top of the root describe block in the rspec document to ensure that views are rendered correctly.

This was the helpful article:
https://github.com/nesquena/rabl/wiki/Testing-with-rspec