Unittest testing assert*() calls rather than methods?

Devin Jeanpierre jeanpierreda at gmail.com
Thu Sep 29 02:50:03 CEST 2011


> I used to ask the same question, but then I decided that if I wanted each
> data point to get its own tick, I should bite the bullet and write an
> individual test for each.

Nearly the entire re module test suite is a list of tuples. If it was
instead a bunch of TestCase classes, there'd be a lot more boilerplate
to write. (At a bare minimum, there'd be two times as many lines, and
all the extra lines would be identical...)

Why is writing boilerplate for a new test a good thing? It discourages
the authorship of tests. Make it as easy as possible by e.g. adding a
new thing to whatever you're iterating over. This is, for example, why
the nose test library has a decorator for generating a test suite from
a generator.

Devin

On Wed, Sep 28, 2011 at 8:16 PM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Tim Chase wrote:
>
>> While I asked this on the Django list as it happened to be with
>> some Django testing code, this might be a more generic Python
>> question so I'll ask here too.
>>
>> When performing unittest tests, I have a number of methods of the
>> form
>>
>>    def test_foo(self):
>>      data = (
>>        (item1, result1),
>>        ... #bunch of tests for fence-post errors
>>        )
>>      for test, result in data:
>>        self.assertEqual(process(test), result)
>>
>> When I run my tests, I only get a tick for running one the one
>> test (test_foo), not the len(data) tests that were actually
>> performed.  Is there a way for unittesting to report the number
>> of passed-assertions rather than the number of test-methods run?
>
> I used to ask the same question, but then I decided that if I wanted each
> data point to get its own tick, I should bite the bullet and write an
> individual test for each.
>
> If you really care, you could subclass unittest.TestCase, and then cause
> each assert* method to count how often it gets called. But really, how much
> detailed info about *passed* tests do you need?
>
> If you are writing loops inside tests, you might find this anecdote useful:
>
> http://mail.python.org/pipermail/python-list/2011-April/1270640.html
>
>
>
> --
> Steven
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



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