Everyone:
I've been using Mocha, which I rather love, to help me test-drive some Rails code. I've run up against something a little clunky, and I'm hoping one of you can help me out.
Suppose I have an Order, which has_many OrderItems. Suppose I want to write a test that checks that when I ask the Order to do something, it asks its order items to do that something. I tried to do this like so:
def test_delegates
order_items = []
3.times {
item = mock("order item", :do_something => nil)
order_items.push(item)
}
order = Order.new(:order_items => order_items)
order.do_something
end
This works with normal objects, but it seems ActiveRecord objects don't like someone passing them Mocha::Mock objects in their constructors. They check that the order items, in this case, are OrderItem objects.
Is there something in ActiveRecord I can override to relax this behavior? I don't like having to create an OrderItem just to add a single stub or expectation.
Thanks for your help.
···
--
J. B. (Joe) Rainsberger :: http://www.jbrains.ca
Your guide to software craftsmanship
JUnit Recipes: Practical Methods for Programmer Testing
2005 Gordon Pask Award for contribution Agile Software Practice
What we tend to do in this case is stub the collection method itself i.e.
Order#order_items.
So you could do something like this...
def test_should_do_something_to_all_order_items
order_items = Array.new(3) { mock('order item', :do_something => nil) }
order = Order.new
order.stubs(:order_items).returns(order_items)
order.do_something
end
When I have a spare couple of hours I'll be releasing a new version of Mocha
that supports mocking of the is_a?. This will allow you to make this work
with ActiveRecord, but with the disadvantage that you are coupling your test
to the innards of ActiveRecord.
I hope that helps.
···
On 28/11/06, J. B. Rainsberger <jbrains762@gmail.com> wrote:
Suppose I have an Order, which has_many OrderItems. Suppose I want to
write a test that checks that when I ask the Order to do something, it
asks its order items to do that something. I tried to do this like so:
def test_delegates
order_items =
3.times {
item = mock("order item", :do_something => nil)
order_items.push(item)
}
order = Order.new(:order_items => order_items)
order.do_something
end
This works with normal objects, but it seems ActiveRecord objects don't
like someone passing them Mocha::Mock objects in their constructors.
They check that the order items, in this case, are OrderItem objects.
Is there something in ActiveRecord I can override to relax this
behavior? I don't like having to create an OrderItem just to add a
single stub or expectation.
--
James.