subprocess-mock 0.2.0

Subprocess Mock

Subprocess Mock

Mock objects for the standard library’s subprocess module

pip install subprocess-mock

Installation in a virtual environment is recommended.

Example Usage

Use a subprocess_mock.ModuleFunctions instance to patch subprocess module functions in unit tests in order to record the calls and - if required - inject called process output and returncode (currently, only the patch method for subprocess.run() has been implemented).

>>> import pathlib
>>> import subprocess
>>> import subprocess_mock
>>> from unittest.mock import patch
>>>
>>> new_file = pathlib.Path("testfile.txt")
>>> new_file.exists()
False
>>>
>>> # Test: call a process with a mock.patched subprocess.run
>>> # The process not called with normal effects,
>>> # but a call is recorded in the subprocess_mock.ModuleFunctions() object
>>>
>>> smf = subprocess_mock.ModuleFunctions()
>>> with patch("subprocess.run", new=smf.run):
...     run_result = subprocess.run(["touch", str(new_file)])
...
>>> run_result
CompletedProcess(args=['touch', 'testfile.txt'], returncode=0)
>>> smf.call_results
[(CompletedProcess(args=['touch', 'testfile.txt'], returncode=0), {})]
>>> new_file.exists()
False
>>>
>>> # Counter-test: call the process without patching subprocess.run
>>> # The process is called with normal effects, no call is recorded
>>>
>>> smf.reset()
>>> smf.call_results
[]
>>> run_result = subprocess.run(["touch", str(new_file)])
>>> new_file.exists()
True
>>> smf.call_results
[]
>>>

Further reading

Please see the documentation at https://blackstream-x.gitlab.io/subprocess-mock for detailed usage information.

If you found a bug or have a feature suggestion, please open an issue here