Michael Foord <mich...@voidspace.org.uk> added the comment:
Spec objects are currently dumb. It would be a new feature to add signature
validation to them.
I think it would be a useful feature though as currently autospec sort of
obsoletes spec objects whilst being more heavyweight and harder to use.
I think it would appropriate to add to 3.8 but not to 3.7.
Compatibility with existing tests is the issue. The obvious answer is a flag to
turn it on/off but that adds complexity to the API.
My gut feeling is that spec objects are far more commonly used in situations
where validation would be useful than a detriment.
> On 31 Mar 2019, at 18:07, Karthikeyan Singaravelan <rep...@bugs.python.org>
> wrote:
>
>
> Karthikeyan Singaravelan <tir.kar...@gmail.com> added the comment:
>
> I am slightly concerned if spec should gain more responsibility than just
> validating attribute access which is mentioned in the docs. With the linked
> PR spec below would also validate the signature which is not done in Python
> 3.7 so this might break code for someone who only wants to validate access
> attribute access and not signature of the methods. It seems the PR also adds
> autospec argument to Mock that is currently not supported though spec and
> spec_set are supported.
>
> from unittest import mock
>
> def foo(lish):
> pass
>
> mock_foo = mock.Mock(spec=foo)
> mock_foo(1, 2)
>
> try:
> mock_foo.non_existent
> except AttributeError:
> print("raises AttributeError for non-existent attribute")
>
> # 3.7
>
> ➜ cpython git:(pr_1982) python3.7 /tmp/foo.py
> raises AttributeError for non-existent attribute
>
> # With PR
>
> ➜ cpython git:(pr_1982) ./python.exe /tmp/foo.py
> Traceback (most recent call last):
> File "/tmp/foo.py", line 7, in <module>
> mock_foo(1, 2)
> File
> "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/unittest/mock.py",
> line 1009, in __call__
> _mock_self._mock_check_sig(*args, **kwargs)
> File
> "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/unittest/mock.py",
> line 103, in checksig
> sig.bind(*args, **kwargs)
> File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/inspect.py",
> line 3016, in bind
> return args[0]._bind(args[1:], kwargs)
> File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/inspect.py",
> line 2937, in _bind
> raise TypeError('too many positional arguments') from None
> TypeError: too many positional arguments
>
> ----------
>
> _______________________________________
> Python tracker <rep...@bugs.python.org>
> <https://bugs.python.org/issue30587>
> _______________________________________
----------
_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue30587>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
