mocha developer - May 2008 - Mocking objects to test Rails Controllers

Hi all,

I''m currently considering the use of Mocha to aid in writing my Rails 
unit/functional tests.

I currently have a Rails model which mixes in a series of methods to 
allow it to talk to an external service.  The code is roughly of this form:

class Person < ActiveRecord::Base

    include SMSNotifier

    def send_notification(message)
       send_sms(number,message)
       # more code/interactions...
    end
end

Assuming I want to test that a call to send_notification calls send_sms 
on the SMSNotifier module, what is the best way to use Mocha to do this? 
    Obviously I don''t want my tests calls to send_notification to 
actually do any SMS sending :-)

I''m assuming Mocha can monkey-patch it''s own
method/expectations over
the SMSNotifier module.  In Java, I''d use dependency injection, but
I''m
trying to find the Ruby way here.

Also I''ve seen that Rails has a folder called test/mocks, can anyone 
provide any examples or links as to the use of this in Rails/Mocha?

Thanks in advance for your assistance,


R.

On Wed, May 28, 2008 at 11:12 AM, Rick Moynihan <rick at calicojack.co.uk>
wrote:
> Hi all,
>
> I''m currently considering the use of Mocha to aid in writing my
Rails
> unit/functional tests.
>
> I currently have a Rails model which mixes in a series of methods to allow
> it to talk to an external service.  The code is roughly of this form:
>
> class Person < ActiveRecord::Base
>
>   include SMSNotifier
>
>   def send_notification(message)
>      send_sms(number,message)
>      # more code/interactions...
>   end
> end
>
> Assuming I want to test that a call to send_notification calls send_sms on
> the SMSNotifier module, what is the best way to use Mocha to do this?
> Obviously I don''t want my tests calls to send_notification to
actually do
> any SMS sending :-)
>
> I''m assuming Mocha can monkey-patch it''s own
method/expectations over the
> SMSNotifier module.  In Java, I''d use dependency injection, but
I''m trying
> to find the Ruby way here.
>
> Also I''ve seen that Rails has a folder called test/mocks, can
anyone provide
> any examples or links as to the use of this in Rails/Mocha?
>
> Thanks in advance for your assistance,
With mocha, this is very simple.  Say goodbye to DI, and forget the
builtin rails/mocks as well.

def test_sends_sms_with_number
  person = Person.new(:number => "5551234567")
  person.expects(:send_sms).with("5551234567", "test msg")
  person.send_notification("test msg")
end

That test will ensure your sms method gets called, and it also removes
its implementation so no actual web service calls are made.

- Rob

http://robsanheim.com
http://thinkrelevance.com

I think Rick was asking how to test from a controller. Assuming that  
the controller intantiates the Person object so you can''t setup with  
Person.new inside your test, you can do:

   Person.any_instance.expects(:send_sms)

--Andrew Vit


On May 28, 2008, at 8:29 AM, Rob Sanheim wrote:
> On Wed, May 28, 2008 at 11:12 AM, Rick Moynihan  
> <rick at calicojack.co.uk> wrote:
>> Hi all,
>>
>> I''m currently considering the use of Mocha to aid in writing
my Rails
>> unit/functional tests.
>>
>> I currently have a Rails model which mixes in a series of methods  
>> to allow
>> it to talk to an external service.  The code is roughly of this form:
>>
>> class Person < ActiveRecord::Base
>>
>>  include SMSNotifier
>>
>>  def send_notification(message)
>>     send_sms(number,message)
>>     # more code/interactions...
>>  end
>> end
>>
>> Assuming I want to test that a call to send_notification calls  
>> send_sms on
>> the SMSNotifier module, what is the best way to use Mocha to do this?
>> Obviously I don''t want my tests calls to send_notification to
>> actually do
>> any SMS sending :-)
>>
>> I''m assuming Mocha can monkey-patch it''s own
method/expectations
>> over the
>> SMSNotifier module.  In Java, I''d use dependency injection,
but I''m
>> trying
>> to find the Ruby way here.
>>
>> Also I''ve seen that Rails has a folder called test/mocks, can
>> anyone provide
>> any examples or links as to the use of this in Rails/Mocha?
>>
>> Thanks in advance for your assistance,
>
> With mocha, this is very simple.  Say goodbye to DI, and forget the
> builtin rails/mocks as well.
>
> def test_sends_sms_with_number
>  person = Person.new(:number => "5551234567")
>  person.expects(:send_sms).with("5551234567", "test
msg")
>  person.send_notification("test msg")
> end
>
> That test will ensure your sms method gets called, and it also removes
> its implementation so no actual web service calls are made.
>
> - Rob
>
> http://robsanheim.com
> http://thinkrelevance.com
> _______________________________________________
> mocha-developer mailing list
> mocha-developer at rubyforge.org
> http://rubyforge.org/mailman/listinfo/mocha-developer

Andrew Vit wrote:
> I think Rick was asking how to test from a controller. Assuming that  
> the controller intantiates the Person object so you can''t setup
with
> Person.new inside your test, you can do:
> 
>    Person.any_instance.expects(:send_sms)
Thanks for this Andrew.  You were right about what I was asking, but 
Rob''s answer gave me enough courage to dive in, and find it pretty much
just worked as expected.

I had my code mocked and tested (to some degree) within 5 minutes.

Yay Mocha! :-)

R.