Re: more automatic tests for containers

On 12/22/11 9:35 PM, John Alfred Nathanael Chee wrote:

On Wed, Dec 21, 2011 at 15:20, Joachim Breitner wrote:

...

I’m not sure what the benefit is here. containers is a “high profile” library which sees lots of effort. Introducing a new testing library (doctest) just to avoid having to add those test cases to the test suite does not seem to gain much, but takes away some flexibility while writing good documentation. Maybe the “==” form is more readable to some users?

Consistent unit tests and documentation seems like a nice benefit to me (don't forget about modifying and deleting unit tests). However, I agree that the structure imposed by doctest might lead to less than tasteful documentation.

I definitely prefer the "==" form for stating laws the interface follows. Doctest came from the Python tradition, which is a very imperative outlook on life. I wonder whether doctest could be modified to better match the programming, documentation, and testing style of Haskell. In particular, I'd expect it to recognize "=="-style statements as things to test. The only real issue is whether those statements should be considered unit tests or properties (testable by QuickCheck and SmallCheck), since those two categories have very different methods of being verified. -- Live well, ~wren