Mock - Mocking and Testing Library¶
mock is a library for testing in Python. It allows you to replace parts of your system under test with mock objects and make assertions about how they have been used.
mock is now part of the Python standard library, available as unittest.mock in Python 3.3 onwards.
This package contains a rolling backport of the standard library mock code compatible with Python 3.6 and up.
Please see the standard library documentation for more details.
- Homepage:
- Download:
- Documentation:
- License:
- Support:
- Code:
- Issue tracker:
- Build status:
Python Version Compatibility¶
Version 1.0.1 is the last version compatible with Python < 2.6.
Version 1.3.0 is the last version compatible with Python 3.2.
Version 2.0.0 is the last version compatible with Python 2.6.
Version 2.0.0 is the last version offering official Jython support.
version 3.0.5 is the last version supporting Python 3.5 and lower.
Installing¶
You can checkout the latest development version from GitHub repository with the following command:
git clone https://github.com/testing-cabal/mock.git
You can install mock with pip:
pip install -U mock
Bug Reports¶
Issues with the backport process, such as compatibility with a particular Python, should be reported to the bug tracker. Feature requests and issues with Mock functionality should be reported to the Python bug tracker.
Changelog¶
See the change log.
Maintainer Notes¶
Development¶
Checkout from git (see Installing) and submit pull requests.
Committers can just push as desired: since all semantic development takes place in cPython, the backport process is as lightweight as we can make it.
If you end up fixing anything backport-specific, please add an entry
to the top of CHANGELOG.rst
so it shows up in the next release
notes.
Releasing¶
NB: please use semver. Bump the major component on API breaks, minor on all non-bugfix changes, patch on bugfix only changes.
Run
release.py [major|minor|bugfix]
which will roll out new NEWS items, bump the version number and create a commit for the release.Review that commit, feel free to amend it if you want to note anything manually in
CHANGELOG.rst
.Push to the
master
branch on https://github.com/testing-cabal/mock.git and the Circle CI automation will take care of pushing releases to PyPI and creating a tag.
Backporting rules¶
If code such as this causes coverage checking to drop below 100%:
def will_never_be_called(): pass
It should be adjusted to the following pattern, preferably upstream, so that the
.coveragerc
in this repo knows to ignore it:def will_never_be_called(): pass # pragma: no cov
If code such as this causes coverage checking to drop below 100%:
def will_never_be_called(): yield
It should be adjusted to the following pattern, preferably upstream, so that the
.coveragerc
in this repo knows to ignore it:def will_never_be_called(): yield # pragma: no cover
If a backported patch applies cleanly, but ends up needing to be skipped, then commit the latest sync point and then revert the problematic commit in an immediately subsequent commit and make a note of the reason for the revert in that commit message.
See bc04ea7 for an example where f4c8dc7 broke compatibility for all Python versions earlier than 3.10.
Backporting process¶
Clone cpython and mock into the same directory, eg:
mkdir vcs cd vcs git clone https://github.com/python/cpython.git git clone https://github.com/testing-cabal/mock.git
Make sure
cpython` is on ``main` and that ``main
branch is fully up to date! Make suremock
is on master and up fully up to date!Create a branch in your
mock
clone and switch to it.Make sure you build a suitable virtualenv for Mock development and activate it. For backporting, this should use Python 3.7+.
Run
backport.py
:cd vcs/mock python backport.py
This will find the next cpython patch that needs to be applied, munge it and attempt to apply it with
git am
.If it succeeds, run the tests and/or push your branch up to a fork and do a pull request into the master branch of the main repo to kick off the continuous integration tests.
If it fails, you’ll have to manually work with what
git status
shows to get the patch committed.If it turns out that there’s nothing that should be applied from the failed commit, run
python backport.py --skip-current
, maybe with--skip-reason
.If you have to make changes, please do a
git commit --amend
and add notes about what needed doing below theSigned-off-by
block.If you have to make changes because tests fail with an applied patch, please make those changes in a followup commit and take note of the “Backporting rules” above.
Rinse and repeat until
backport.py
reports no more patches need applying.If
backport.py
has updatedlastsync.txt
but not committed it, now would be a good time to commit that change.
Checking coverage in upstream¶
Assuming you have the checkout structure as above, and you have compiled your cpython master branch, then roughly as follows:
~/vcs/cpython/python.exe -m venv ~/virtualenvs/cpython-master
source ~/virtualenvs/cpython-master/bin/activate
pip install -U setuptools pip
pip install pytest pytest-cov
cd vcs/cpython/Lib/unittest
pytest --cov unittest.mock --cov unittest.test.testmock \
--cov-config ~/vcs/git/mock/.coveragerc \
--cov-report term-missing:skip-covered \
test/testmock/test*
Ignore test/testmock/__*__.py
as these aren’t present in the backport.