Hi,
I’m having a problem writing a proper test for an exercise from “Agile
Web
Development with Rails 4.0”. The exercise was about creating a member
route, which was then used via ajax to decrement an cart item (ListItem)
attribute, eventually destroying it when it hits 0. The route I wrote
is:
resources :line_items do
member do
post ‘decrement’
end
end
Controller function ‘decrement’ uses a params[:id] for internal
processing.
The test I wanted to write was to check if the controller ‘decrement’
function indeed destroys the LineItem when its quantity
(line_item.quantity) hits zero. I’ve therefore created a fixture:
one:
product_id: 0
cart_id: 0
quantity: 1
and assigned it to @line_item in my ‘line_items_controller_test.rb’,
where
I wrote this test:
test “should destroy line_item via ajax” do
assert_difference(‘LineItem.count’) do
xhr :post, :decrement, id: @line_item
end
end
However, this throws the following error in my face:
LineItemsControllerTest#test_should_destroy_line_item_via_ajax:
NoMethodError: undefined method id' for nil:NilClass app/controllers/line_items_controller.rb:16:indecrement’
test/controllers/line_items_controller_test.rb:61:in block (2 levels) in <class:LineItemsControllerTest>' test/controllers/line_items_controller_test.rb:60:inblock in
class:LineItemsControllerTest’
I tried variations of different parameters to xhr but with no success.
I’ve
also tried fixing the route passed by consulting rake routes, but it
appears I don’t really understand how this works. Any help would be
deeply
appreciated.
Thanks,
arca0