On Mar 20, 2011, at 11:38 PM, andyl wrote: > OK - I got this working using mocha and the 'any_instance' method. > > A gist with working examples is here: https://gist.github.com/879029 > > It looks like rspec mocks had an 'any_instance' method, but it was removed > because it promoted 'bad practice'.
It was never released, and was removed because the patch was incomplete in retrospect. There is an open issue on this right now, with a patch in progress that I hope to include in the next release, assuming it is ready when that release is ready to go. > I'm curious to understand how 'any_instance' promotes bad practice. I found > it useful in my situation, to stub out slow network code that crushed my test > performance. In general, we want test code to be as narrow and precise as possible. This means we should control which objects we are dealing with at any moment. any_instance is a bandaid for a situation in which the design makes it difficult to get a handle on a specific instance. If we're actually doing TDD this should never happen, but sometimes we use frameworks like ActiveRecord, which provides two different objects in this scenario: widget = Factory(:widget) found_widget = Widget.find(widget.id) These two objects ^^ have the same attributes, but are not the same object. This means that stubbing methods on widget does not have any impact on found_widget. In this case, any_instance saves the day, but it leaves open some holes in tests. Consider: order = Factory(:order) Order.any_instance.should_receive(:confirm) put :confirm, :order_id => order.id If the examples and code change over time such that there are more than one order at play and the wrong one receives confirm(), this example will still pass. FYI - ActiveRecord will soon have an identity map, which means that this code will work: order = Factory(:order) order.should_receive(:confirm) put :confirm, :order_id => order.id This is a much better situation as it is very precise. HTH, David _______________________________________________ rspec-users mailing list rspec-users@rubyforge.org http://rubyforge.org/mailman/listinfo/rspec-users
