Rails%203%20In%20Action

366 CHAPTER 13 Designing an API
To get started with this show action, you’ll write a test in spec/api/v1/
projects_spec.rb for it inside the “projects viewable by this user” context block, as
shown in the following listing.
Listing 13.13 spec/api/v1/projects_spec.rb
context "show" do
let(:url) { "/api/v1/projects/#{@project.id}"}
before do
Factory(:ticket, :project => @project)
end
it "JSON" do
get "#{url}.json", :token => token
project = @project.to_json(:methods => "last_ticket")
last_response.body.should eql(project)
last_response.status.should eql(200)
project_response = JSON.parse(last_response.body)["project"]
ticket_title = project_response["last_ticket"]["ticket"]["title"]
ticket_title.should_not be_blank
end
end
You’re using the project method that was set up by the “projects viewable by this
user” context block earlier to generate the URL to a Project resource, as well as using
it to create a new ticket for this project so that last_ticket returns something of
value. You take this URL and do a JSON request on it, and you expect to get back a
JSON representation of the object with the last_ticket method being called and also
returning data. Then you check that the response’s status should be 200, indicating a
good request, and finally you check that the last ticket title isn’t blank.
To make this test pass, open app/controllers/api/v1/projects_controller.rb and add
in the show action, as shown in the following listing.
Listing 13.14 app/controllers/api/v1/projects_controller.rb
def show
@project = Project.find(params[:id])
respond_with(@project, :methods => "last_ticket")
end
In this action, you find the Project based on the params[:id] value and then
respond_with this object, asking it to call the last_ticket method. If this method is
undefined (as it is right now), then the method will not be called at all. When you run
this test with bin/rspec spec/api/v1/projects_spec.rb, you’ll see this error:
Failure/Error: ticket_title = last_response ...
You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.[]