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Title: Provide assertion functions in unittest.mock
Type: enhancement Stage: resolved
Components: Library (Lib) Versions: Python 3.7
Status: closed Resolution: duplicate
Dependencies: Superseder: Mock.assert* API is in user namespace
View: 24651
Assigned To: Nosy List: berker.peksag, odd_bloke, ppperry, tribaal
Priority: normal Keywords:

Created on 2017-07-17 14:36 by odd_bloke, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (3)
msg298533 - (view) Author: Daniel Watkins (odd_bloke) * Date: 2017-07-17 14:36
The convenience assertion methods on mock objects can be easily mistyped and if they are mistyped, they will silently pass.  This can be quite user-hostile.  Consider the following:

>>> example = Mock()
>>> example.assert_called_once()
>>> example.assert_caled_once_with(...)

This will not raise any exceptions, though the first feels natural and the latter is misspelt.  To avoid using the methods, one can type:

>>> example = Mock()
>>> assert example.call_count == 1
>>> assert example.call_args_list == [call(...)]

but the meaning of that latter statement is particularly non-obvious.  Instead, it would be great if I could import the assertions from mock as functions, and call them with mock as the first argument:

>>> from unittest.mock import assert_called_once  # This will be an ImportError
>>> example = Mock()
>>> assert_caled_once_with(example, ...)  # A NameError
>>> assert_called_once_with(example, ...)  # Great success!
msg298553 - (view) Author: (ppperry) Date: 2017-07-17 20:29
You can already do this, although it it somewhat of a hack:

>>> assert_called_once=Mock.assert_called_once # This will be an AttributeError
>>> assert_called_once_with=Mock.assert_called_once_with
>>> example = Mock()
>>> assert_caled_once_with(example, ...)  # A NameError
>>> assert_called_once_with(example, ...)  # Great success!
msg305036 - (view) Author: Berker Peksag (berker.peksag) * (Python committer) Date: 2017-10-26 08:37
Thank you for the report. This is a duplicate of issue 24651.
Date User Action Args
2022-04-11 14:58:49adminsetgithub: 75132
2017-10-26 08:37:33berker.peksagsetstatus: open -> closed

superseder: Mock.assert* API is in user namespace
nosy: + berker.peksag
components: + Library (Lib), - Tests

messages: + msg305036
type: enhancement
resolution: duplicate
stage: resolved
2017-07-17 20:29:52ppperrysetnosy: + ppperry
messages: + msg298553
2017-07-17 14:40:49tribaalsetnosy: + tribaal
2017-07-17 14:36:43odd_blokecreate