On 20 May 2013, at 18:26, Mark Janssen <dreamingforw...@gmail.com> wrote:
>>> I'm hoping that core developers don't get caught-up in the "doctests are bad >>> meme". >>> >>> Instead, we should be clear about their primary purpose which is to test >>> the examples given in docstrings. >>> In other words, doctests have a perfectly legitimate use case. >> >> But more than just one ;-) Another great use has nothing to do with >> docstrings: using an entire file as "a doctest". This encourages >> writing lots of text explaining what you're doing,. with snippets of >> code interspersed to illustrate that the code really does behave in >> the ways you've claimed. > > +1, very true. I think doctest excel in almost every way above > UnitTests. I don't understand the popularity of UnitTests, except > perhaps for GUI testing which doctest can't handle. I think people > just aren't very *imaginative* about how to create good doctests that > are *also* good documentation. > Doc tests have lots of problems for unit testing. * Every line is a test with *all* output part of the test - in unit tests you only assert the specific details you're interested in * Unordered types are a pain with doctest unless you jump through hoops * Tool support for editing within doctests is *generally* worse * A failure on one line doesn't halt execution, so you can get many many reported errors from a single failure * Try adding diagnostic prints and then running your doctests! * Tools support in terms of test discovery and running individual tests is not as smooth * Typing >>> and ... all the time is really annoying * Doctests practically beg you to write your code first and then copy and paste terminal sessions - they're the enemy of TDD * Failure messages are not over helpful and you lose the benefit of some of the new asserts (and their diagnostic output) in unittest * Tests with non-linear code paths (branches) are more painful to express in doctests and so on... However doctests absolutely rock for testing documentation / docstring examples. So I'm with Raymond on this one. All the best, Michael > That serves two very good purposes in one. How can you beat that? > The issues of teardown and setup are fixable and even more beautifully > solved with doctests -- just use the lexical scoping of the program to > determine the execution environment for the doctests. > >> picking-your-poison-ly y'rs - tim > > Cheers, > > Mark > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > http://mail.python.org/mailman/options/python-dev/fuzzyman%40voidspace.org.uk -- http://www.voidspace.org.uk/ May you do good and not evil May you find forgiveness for yourself and forgive others May you share freely, never taking more than you give. -- the sqlite blessing http://www.sqlite.org/different.html _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
