unittest help needed!

Phlip phlip2005 at gmail.com
Thu Jan 14 20:51:42 CET 2010

Oltmans wrote:
>     def test_first(self):
>         print 'first test'
>         process(123)

All test cases use the pattern "Assemble Activate Assert".

You are assembling a 123, and activating process(), but where is your assert? If 
it is inside process() (if process is a test-side method), then that should be 
called assert_process().

> As you can see, every test method is almost same. Only difference is
> that every test method is calling process() with a different value.
> Also, I've around 50 test methods coded that way.

We wonder if your pattern is truly exploiting the full power of testing. If you 
have ~15 different features, you should have ~50 tests (for a spread of low, 
middle, and high input values, to stress the targeted production code).

But this implies your 15 different features should have as many different 
interfaces - not the same interface over and over again. That suggests coupled 

Anyway, the short-term answer is to temporarily abandon "AAA", and roll up your 
input values into a little table:

    for x in [123, 327, 328, ... ]:

(Also, you don't need the print - tests should run silent and unattended, unless 
they fail.)

This refactor is the standard answer to the question "I have an unrolled loop". 
You roll it back up into a table iteration.

However, you lose the test case features, such as restartability and test 
isolation, that AAA give you.

Long term, you should use a literate test runner, such as (>cough<) my Morelia 


Down at the bottom, that shows how to create a table of inputs and outputs, and 
Morelia does the unrolling for you.


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