[Python-Dev] How far to go with user-friendliness

[Erik Bray]

On Tue, Jul 14, 2015 at 6:22 PM, Robert Collins
<robertc at robertcollins.net> wrote:
> For clarity, I think we should:
>  - remove the assret check, it is I think spurious.
>  - add a set of functions to the mock module that should be used in
> preference to Mock.assert*
>  - mark the Mock.assert* functions as PendingDeprecation
>  - in 3.6 move the PendingDeprecation to Deprecated
>  - in 3.7 remove the Mock.assert* functions and the check for method
> names beginning with assert entirely.

Hi all,

I'm just an onlooker, and haven't read every word of this thread.  In
fact I worry that it's pointless to reply to rather than starting a
new thread.  I just wanted to make sure that the specific message I'm
replying too wasn't lost in the noise because I think Robert's
suggestion makes vastly more sense than anything else I've seen here
(I came searching through the thread to see if anyone else suggested
this before I started a thread to do so).

I don't think it makes any sense to have magic assert_ methods on the
Mock object.  Not only does the "magic" clearly lead to too many
ambiguities and other problems--I think they make less sense from an
API standpoint in the first place.  Typically asserting something in a
test is not something an object *does*--a method.  More often we as a
test writers assert something *about* an object.  The assertion is an
external tool meant to measure and introspect things about the system
under observation.  In this case, although Mock is itself a testing
tool, we're introspecting something about the Mock object as external
observers.

***Assertions on Mock objects should be implemented as stand-alone
functions (that happen to be used primarily on Mock objects as
input).***

Aside from, in my mind, making more sense philosophically, using
specialized assert functions for this has absolutely none of the
spelling ambiguities or other problems of the magic methods.

I'm -0 on removing the assret_ methods unless no one is using them
yet.  I don't care if they're there as long as they're deprecated
along with the other magic methods of Mock.

Best,
Erik