[TIP] setUp and tearDown behavior

[Olemis Lang]

On Mon, Jan 18, 2010 at 9:37 PM, Alfredo Deza <arufuredosan at gmail.com> wrote:
> I am building some tests for a Python installer that copies some files and
> changes some permissions.
>
> Nothing weird there.
>
> However, in the test class I am starting with a setUp that basically calls
> the installer (so the tests can see if everything is where it should be),
> this is followed by a few assertions and finally a tearDown is called where
> everything gets uninstalled.
>
> When running the tests with nosetests, I see that setUp and tearDown are
> called for *every* method in my test class (e.g. installs => runs test
> method => uninstalls ....)
>

That's the way it should be. In XUnit the calls are performed like this

setUp
test_1
tearDown
setUp
test_2
tearDown
setUp
test_3
tearDown
...

> Isn't setUp supposed to be run once at the beginning of the class? or is
> this expected?
>

In order to do this you need to use Shared Fixture Setup testing
pattern. For instance I recently included support for that in `dutest`
(doctest + unittest) to solve problems similar to yours. In this case
I create and setup a Trac environment just once before running all
Trac-related test cases, and tear it down once everything's been done
.

In JUnit>=4 jargon what you'd need is a BeforeClass and AfterClass

> In case this is expected, is there a way to do it just once for all the
> methods?
>

Using standard `unittest` module ? well ... no.

-- 
Regards,

Olemis.

Blog ES: http://simelo-es.blogspot.com/
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