[Python-ideas] ABC: what about the method arguments ?
tjreedy at udel.edu
Fri Sep 24 18:20:49 CEST 2010
On 9/24/2010 10:17 AM, Daniel Stutzbach wrote:
> On Thu, Sep 23, 2010 at 7:24 PM, Terry Reedy
> <tjreedy at udel.edu
> <mailto:tjreedy at udel.edu>> wrote:
> Can this work? Split the current test suite for a concrete class
> that implements one of the ABCs into concrete-specific and
> ABC-general portions, with the abstract part parameterized by
> concrete class.
> For instance, split test/test_dict.py into test_dict.py and
> test_Mapping.py, where the latter has all tests that test compliance
> with the Mapping ABC (or whatever it is called) and the former keeps
> all the dict-specific extension tests. Rewrite test_Mapping so it is
> not dict specific, so one could write something like
Reading the responses, I realized that I am already doing a simplified
version of my suggestion for functions rather than classes. For didactic
purposes, I am writing multiple implementations of multiple abstract
functions. I embody a test for a particular function in an iterable of
input-output pairs (where the 'output' can also be an exception class).
I use that with a custom super test function that tests one or more
callables against the pairs. It works great and it is easy to add
another implementation or more pairs.
> As a heavy user of the ABCs in the collections module, that would be
> awesome. :-) It would make my life a lot easier when I'm writing tests
> to go along with an ABC-derived class. I have 8 such classes on PyPi
> (heapdict.heapdict and blist.*), plus more in private repositories.
> There is some code vaguely along those lines in the existing unit tests.
> For example, Lib/test/seq_tests.py contains tests common to sequences.
> However, that was written before collections.Sequence came along and
> the pre-2.6 definition of "sequence" only loosely correlates with a
Well, pick one existing test file, revise and extend and perhaps split,
start a tracker issue with proposed patch, get comments, and perhaps
commit it. If you do, add terry.reedy as nosy.
Terry Jan Reedy
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