[Python-Dev] Tweaking the stdlib test infrastructure (original) (raw)

Collin Winter collinw at gmail.com
Tue Apr 24 02:39:42 CEST 2007

Fast and simple: I want all stdlib test cases to stop subclassing unittest.TestCase and start subclassing test_support.TestCase.

Why: With a single parent class common to the entire stdlib, adding new functionality/testing instruments to every single test at once becomes trivial. One example would be to move "regrtest -R"'s focus from module-level refleaks to test case-level refleaks (that is, looped execution of individual test cases, rather than test modules). I intend to implement this new refleak checking soon, if this base change goes ahead.

How: At first, test_support.TestCase could be as simple as "TestCase = unittest.TestCase". Once we want to extend the test harness's capabilities, we change it to "class TestCase(unittest.TestCase): blah blah blah". All code under Lib/test/ is changed to subclass the proper class. test_support.run_unittest() can be modified to make sure that incoming classes inherit as they're supposed to.

But that sounds like a lot of work: yes, but that's what we have regexes for. Most of this work can be done with a few global search-and-replace operations.

So: any objections to making this change?

Collin Winter

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