Rails - Jul 2006 - Testing which RuntimeError is raised

I am just starting to use unit testing. Way cool. But I am not finding
very clear docs on assert_raise. I have managed to write a test that
tells me that the destroy I am trying to test fails with a
RuntimeError (as it should). However, I would really like to test that
it rails for the specific reason I have in my model. How can I get
more specific? Am I going to have to create my own exception class so
I have a  named exception to check for? What I have a the moment is:

In my model file:

  # don''t destroy the home page (id = 1)
  before_destroy :dont_destroy_homepage

  def dont_destroy_homepage
    raise "You can''t delete the home page or you will get rid of
your
entire site" if id == 1
  end

Then in my test file:

  def test_cant_destroy_homepage
    homepage = pages(:homepage)
    assert_equal homepage.id, 1
    # I would really love to figure out how to test what RuntimeError is raised
    assert_raise(RuntimeError) {homepage.destroy}
  end


-- 
Cynthia Kiser

exception = assert_raise(RuntimeError) {homepage.destroy}
puts exception.message

(I think)

Chris

On 7/18/06, Cynthia Kiser <cynthia.kiser@gmail.com>
wrote:
> I am just starting to use unit testing. Way cool. But I am not finding
> very clear docs on assert_raise. I have managed to write a test that
> tells me that the destroy I am trying to test fails with a
> RuntimeError (as it should). However, I would really like to test that
> it rails for the specific reason I have in my model. How can I get
> more specific? Am I going to have to create my own exception class so
> I have a  named exception to check for? What I have a the moment is:
>
> In my model file:
>
>   # don''t destroy the home page (id = 1)
>   before_destroy :dont_destroy_homepage
>
>   def dont_destroy_homepage
>     raise "You can''t delete the home page or you will get rid
of your
> entire site" if id == 1
>   end
>
> Then in my test file:
>
>   def test_cant_destroy_homepage
>     homepage = pages(:homepage)
>     assert_equal homepage.id, 1
>     # I would really love to figure out how to test what RuntimeError is
raised
>     assert_raise(RuntimeError) {homepage.destroy}
>   end
>
>
> --
> Cynthia Kiser
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

On 7/18/06, Chris Roos <chrisjroos@gmail.com>
wrote:
> exception = assert_raise(RuntimeError) {homepage.destroy}
> puts exception.message
Thanks Chris. That does indeed print the message to the console - and
told me how to access the message. I altered my test to then assert
the message was what I wanted:

  def test_cant_destroy_homepage
    homepage = pages(:homepage)
    assert_equal homepage.id, 1
    problem = assert_raise(RuntimeError) {homepage.destroy}
    assert_equal "You can''t delete the home page",
problem.message
  end

And I was please to note that the assert_raise still counted in my
number of assertions.
-- 
Cynthia Kiser
cynthia.kiser@gmail.com