# RSpec - Having trouble mocking model associations

**URL:** <https://www.ruby-forum.com/t/rspec-having-trouble-mocking-model-associations/142449>\
**Category:** Rails\
**Created:** [July 8, 2008, 2:57am UTC](https://www.ruby-forum.com/t/rspec-having-trouble-mocking-model-associations/142449 "2008-07-08T02:57:43Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![wemagor](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/8edcca/32.png) [@wemagor](https://www.ruby-forum.com/u/wemagor)\
**Post date:** [July 8, 2008, 2:57am UTC](https://www.ruby-forum.com/t/rspec-having-trouble-mocking-model-associations/142449/1 "2008-07-08T02:57:43Z")

</div>

Hi everyone,

I’m having a devil of a time trying to figure out why this spec keeps  
giving  
me an error. I’m attempting to mock out a class I haven’t created yet  
(User) so I don’t need to worry about creating it at the moment. I  
could  
have sworn I read somewhere that it was possible to pass a mock object  
as an  
attribute to an associated class, but it’s just not working for me.

Here’s the code I have:

# task\_spec.rb

describe Task do  
before(:each) do  
user\_proxy = mock(‘user’)  
@task = Task.new(  
:description =\> “Sample task description”,  
:assigned\_user =\> user\_proxy  
)  
end

it “should be valid with all required attributes” do  
@task.should be\_valid  
end

it “should be invalid without a description” do  
@task.description = nil  
@task.should\_not be\_valid  
@task.should have(1).error\_on(:description)  
end

it “should be invalid unless assigned to a user” do  
@task.assigned\_user = nil  
@task.should\_not be\_valid  
@task.should have(1).error\_on(:assigned\_user\_id)  
end  
end

# task.rb

class Task \< ActiveRecord::Base  
belongs\_to :assigned\_user, :class =\> “User”, :foreign\_key =\>  
“assigned\_user\_id”

validates\_presence\_of :description  
validates\_presence\_of :assigned\_user\_id # Validate against the foreign  
key, not the association  
end

* * *

When I try to run this, I get an error stating “uninitialized constant  
Task::User”, presumably because of the belongs\_to – I’m certain I saw  
somewhere that you could mock this so I didn’t _have_ to create the User  
class when I’m only concerned with the Task class, but I can’t for the  
love  
of me figure out how it was done, and I can’t remember where it was I  
saw it  
to check.

The problem I’m having is that the two validation checks are working,  
but no  
matter what the first one (the one that checks if it IS valid) always  
returns false. I tried changing the before block to this:

before(:each) do  
user\_proxy = mock(‘user’, :id =\> 1)  
@task = Task.new(  
:description =\> “Sample”  
)  
@task.stub!(:assigned\_user).and\_return(user\_proxy)  
end

but still nothing; the “should be valid” spec fails, but the other two  
are  
passing like they should. I attempted to debug the code by checking  
that  
there were no error messages ( e.g. @task.errors.full\_messages.should ==  
[]  
) and that _passed_, but valid? is still showing as false.

As you can probably tell, I’m a little new to using RSpec and BDD, and  
I’ve  
never done anything with mocks or stubs before. None of the tutorials  
I’ve  
read through so far have dealt with a model that has associations, and  
needs  
to make sure that it’s assigned to an association. In this case I’m  
trying  
to make sure that a task has been assigned to a user before it gets  
saved,  
but I’m trying to avoid having to stop and create the User class, since  
I’m  
not sure at this point how I’m going to implement it, and I don’t want  
to  
implement a dummy class.

If someone could point me in the right direction, I’d greatly appreciate  
it.