Unit testing validates_associated and HABTM relationships

Rails
1

I’m trying to set up some unit tests and they are failing on just
basic tests on one model.

The failure is:

  1. Failure:
    test_invalid_with_empty_attributes(WorkAreaTaskTest)
    [test/unit/work_area_task_test.rb:15]:
    is not true.

My model is:

class WorkAreaTask < ActiveRecord::Base

belongs_to :task
belongs_to :work_area
has_many :employee_tasks, :dependent => :destroy

acts_as_list :scope => :work_area

validates_presence_of :task_id
validates_presence_of :work_area_id

validates_presence_of :task
validates_associated :task

end

And my unit test is:

class WorkAreaTaskTest < Test::Unit::TestCase
fixtures :work_area_tasks, :employee_type_tasks, :tasks, :work_areas

Replace this with your real tests.

def test_truth
assert true
end

def test_invalid_with_empty_attributes
work_area_task = WorkAreaTask.new

 assert !work_area_task.valid?
 assert work_area_task.errors.invalid?(:task_id)
 assert work_area_task.errors.invalid?(:work_area_id)
 assert work_area_task.errors.invalid?(:task)

end
end

The failure occurs at the assert invalid tests.

–
Sterling A.
sterling [at] sterlinganderson.net
http://sterlinganderson.net/

2

Can’t tell from your posting which line is line 15. Where exactly is it
failing?

3

I don’t know why you are checking the id’s. The id’s are usually keys
that
are generated automatically when you save the model. Is there any reason
why
you are validating id’s?

If you cannot save the model, the id fields will be blank.

4

It’s failing on this line:

assert work_area_task.errors.invalid?(:task_id)

The only way to get it to not fail is to comment that line and the
next 2 as well. So it’s like is getting the the IDs and the task from
somewhere, because they should be empty.

On 12/4/06, Bala P. [email protected] wrote:

  1. Failure:
    test_invalid_with_empty_attributes(WorkAreaTaskTest)
    [test/unit/work_area_task_test.rb:15]:
    is not true.

–
Sterling A.
sterling [at] sterlinganderson.net
http://sterlinganderson.net/
608.239.8387

5

I’m not checking the id’s from the model I am testing. I am checking
the foreign key id’s, ie. the id’s from the related tables that need
to be there for the model to be valid. That’s why I am checking for
them.

On 12/4/06, Bala P. [email protected] wrote:

–
Sterling A.
sterling [at] sterlinganderson.net
http://sterlinganderson.net/
608.239.8387

6

Read this first: Peak Obsession

Test the behavior, not the implementation. You don’t have to check the
foreign keys. You can save a valid record and read it back and compare
it
with fixture data. It is very similar to the example from the above
tutorial. Remove validates_presence_of :task_id, :work_area_id from your
model class. I would love to be proved wrong here.

7

Yes. Also before you start writing tests, jot down specifications in a
sheet
of paper. Then write : test_should_your_written_specification_one, two
etc.
When you do TDD really well you are actually thinking in terms of
behavior.

If you really want to push the envelope and have some time to kill, then
check out rSpec. There is a nice Google video that was presented at
Google
about rSpec.

For your viewing pleasure:
http://video.google.com/videoplay?docid=8135690990081075324&q=bdd&hl=en

8

Ahhh. I see what you are saying. Rooky mistake on my part. :slight_smile:

So basically the belongs_to is going to take care of the foreign keys,
so there’s no reason for me to have “validates_X_of” for them is what
you are saying?

On 12/4/06, Bala P. [email protected] wrote:

I’m not checking the id’s from the model I am testing. I am checking
the foreign key id’s, ie. the id’s from the related tables that need
to be there for the model to be valid. That’s why I am checking for
them.

–
Sterling A.
sterling [at] sterlinganderson.net
http://sterlinganderson.net/