rspec users - Aug 2011 - mock weirdness

Hi,

I have a strange problem with mocking an object that has a method called
''load''. With Rails 2.3 and rspec-rails 1.3 I could do sth like
this:

describe Foo do
  let(:bar) { mock(Bar).as_null_object }
  before(:each) do
    Bar.stub(:new).and_return(bar)
  end

  it ''does something'' do
    Foo.do_something
  end
end

with

class Foo
  def do_something
    bar = Bar.new
    bar.load
  end
end

After an upgrade to rails 3.0.10 and rspec-rails 2.6.1 I get an
ArgumentError:
  wrong number of arguments (0 for 1)

If I add "bar.method(:load)" to do_something(), it prints

#<Method: RSpec::Mocks::Mock(ActiveSupport::Dependencies::Loadable)#load>

which doesn''t look right to me. I am using ree-1.8.7-2011.03.

Does anyone have an idea what this is about and how to properly deal
with this?

cheers,

Nikolay

--
"It''s all part of my Can''t-Do approach to life."
Wally

On Aug 22, 2011, at 5:11 AM, Nikolay Sturm wrote:
> Hi,
> 
> I have a strange problem with mocking an object that has a method called
> ''load''. With Rails 2.3 and rspec-rails 1.3 I could do sth
like this:
> 
> describe Foo do
>  let(:bar) { mock(Bar).as_null_object }
>  before(:each) do
>    Bar.stub(:new).and_return(bar)
>  end
> 
>  it ''does something'' do
>    Foo.do_something
>  end
> end
> 
> with
> 
> class Foo
>  def do_something
>    bar = Bar.new
>    bar.load
>  end
> end
> 
> After an upgrade to rails 3.0.10 and rspec-rails 2.6.1 I get an
> ArgumentError:
>  wrong number of arguments (0 for 1)
> 
> If I add "bar.method(:load)" to do_something(), it prints
> 
> #<Method:
RSpec::Mocks::Mock(ActiveSupport::Dependencies::Loadable)#load>
This ^^ tells you everything you need to know to research the problem.

If you look at the code for ActiveSupport::Dependencies
(https://github.com/rails/rails/blob/v3.0.10/activesupport/lib/active_support/dependencies.rb),
you''ll see that the Loadable module is included in every object. See:

 
https://github.com/rails/rails/blob/v3.0.10/activesupport/lib/active_support/dependencies.rb#L654
 
https://github.com/rails/rails/blob/v3.0.10/activesupport/lib/active_support/dependencies.rb#L281-286

This means that even mock objects already have a load method, which is defined
to accept one or more arguments:

 
https://github.com/rails/rails/blob/v3.0.10/activesupport/lib/active_support/dependencies.rb#L234-236

This means that you need to explicitly stub the load method to do what
you''re trying to do:

  let(:bar) { mock(Bar, :load => nil).as_null_object }

HTH,
David
> which doesn''t look right to me. I am using ree-1.8.7-2011.03.
> 
> Does anyone have an idea what this is about and how to properly deal
> with this?
> 
> cheers,
> 
> Nikolay

* David Chelimsky [2011-08-22]:
> This means that you need to explicitly stub the load method to do what
> you''re trying to do:
>
>   let(:bar) { mock(Bar, :load => nil).as_null_object }
Thanks for the explanation, David. I wasn''t sure whether or not this
was
accepted behaviour, I would have expected a null object to be, well, an
object without methods. At least the next guy''s google search will
point
to the solution. :)

cheers,

Nikolay