rspec users - Jun 2008 - Using and_yield to pass multiple or no iterations

Hi, imagine there''s a class called Egg which has the following method
(which calls another method):

<CODE>
def do_thing
  has_iterated = false

  self.each_row do |row|
    has_iterated = true unless has_iterated
  end

  has_iterated
end
</CODE>

Stupid code, I know.
I have two questions with it. The first is, would it be possible to set
it up to test the case when each_row operates on an empty Array? Sort of
like this:

<SPEC>
it "should return false if it does not iterate over anything" do
  @egg.stub!( each_row ).and_yield( nil ) # I know this doesn''t work
  @egg.do_thing.should be_false
end

it "should return true if it does iterate over something" do
  @egg.stub!( each_row ).and_yield( :value )
  @egg.do_thing.should be_true
end
</SPEC>

Secondly, is this the best (correct) way to pass multiple values to
iterate over?

<SPEC>
it "should be doing something else, too"
  @egg.stub!( :each_row ).
    and_yield( :first_value ).
    and_yield( :second_value ).
    and_yield( :third_value )
  @egg.do_thing.should be_true
end
</SPEC>

As you can see, my understanding of and_yield() is *very* imperfect, so
any & all pointers are very gratefully received.
Cheers,
   Doug.
-- 
Posted via http://www.ruby-forum.com/.

On Thu, Jun 5, 2008 at 5:46 AM, Doug Livesey <lists at ruby-forum.com>
wrote:
> I have two questions with it. The first is, would it be possible to set
> it up to test the case when each_row operates on an empty Array?
If there were no rows, each_row wouldn''t yield at all, so you should
just be able to do
  @o.stub! :each_row
(with no and_yield). Note that Ruby is happy to let you associate a
block with any method call, whether it''s expected or not.
-hume.