[Python-Dev] unittest's redundant assertions: asserts vs. failIf/Unlesses

[Michael Foord]

Guido van Rossum wrote:
> On Wed, Mar 19, 2008 at 5:16 PM, Jeffrey Yasskin <jyasskin at gmail.com> wrote:
>   
>> On Wed, Mar 19, 2008 at 2:15 PM,  <glyph at divmod.com> wrote:
>>  >
>>  >  On 02:21 pm, murman at gmail.com wrote:
>>  >  >>OTOH, I'd rather there be OOWTDI so whatever the consensus is is fine
>>  >  >>with me.
>>  >  >
>>  >  >This strikes me as a gratuitous API change of the kind Guido was
>>  >  >warning about in his recent post: "Don't change your APIs incompatibly
>>  >  >when porting to Py3k"
>>  >
>>  >  I agree emphatically.  Actually I think this is the most extreme case.
>>  >  The unit test stuff should be as stable as humanly possible between 2
>>  >  and 3, moreso than any other library.
>>
>>  This is convincing for me. Move my +1 back to 3.1.
>>     
>
> Same here; let's tread carefully here and not change this with 3.0.
> Starting to deprecate in 3.1 and killing in 3.3 would be soon enough.
> I like using only the assertKeyword variants, removing assert_, fail*,
> and assertEquals. However I don't like changing assertTrue and
> assertFalse to insist that the value is exactly True or False -- if
> you really care that much, let's add assertIs(x, y) which asserts that
> x and y are the same object. I also think that all tests should use
> the operator their name implies, e.g. assertEqual(x, y) should do
> something like
>
>   if x == y:
>     pass
>   else:
>     raise AssertionError(...)
>
> rather than
>
>   if x != y:
>     raise AssertionError(...)
>
> Someone please open a bug for this task.
>
>   
This sounds like a good compromise and I'm happy to take on the cleanup 
- unless someone else beats me to it. I guess it should wait until 3.0 
final is out of the door before adding the DeprecationWarnings.

Michael Foord