pytest-cli-fixtures

pytest-cli-fixtures

The pytest-cli-fixtures plugin provides a way to automatically register fixtures based off of command line argument definitions. This plugin will also allow mandatory arguments to be omitted from the command line when tests don't use the fixtures that they are associated with.

Usage

There is only one hook function that is needed to use CLI fixtures:

def pytest_add_cli_fixtures(parser):
    ...

This hook is similar to the built-in pytest_addoption hook, and the parser object that is provided is the same as in the built-in hook.

Note: Like the built-in pytest_addoption hook, the pytest_add_cli_fixtures hook should only be implemented in plugins, or in conftest.py.

Installation

This plugin is available on PyPI:

> pip install pytest-cli-fixtures

Note: This plugin requires pytest version 7.0 or later.

Example

The following conftest.py defines a --value argument within the my args group. Since it specifies a dest, the fixture relating to the value will be called my_val. The argument specifies required=True, meaning that pytest will return an error if a test uses the my_val fixture but --value isn't specified on the command line.

# conftest.py

def pytest_add_cli_fixtures(parser):
    group = parser.getgroup('my args')
    group.addoption('--value', dest='my_val', type=int, required=True)

With the following test file, the --value argument must be specified or pytest will return an error. Alternatively, filters would need to be used to exclude the test that uses the CLI fixture.

# test_something.py

def test_something_else():
    assert 1 + 2 == 3


def test_value(my_val):
    assert 1 + my_val == 3

Without arguments

> pytest example
=================================== test session starts ====================================
platform win32 -- Python 3.10.5, pytest-7.1.2, pluggy-1.0.0
rootdir: C:\...\pytest-cli-fixtures, configfile: pytest.ini
plugins: cli-fixtures-1.0
collected 2 items

================================== no tests ran in 0.01s ===================================
ERROR: usage: pytest [options] [file_or_dir] [file_or_dir] [...]
pytest: error: the following arguments are required: --value

Filter out test that uses CLI fixture

> pytest example -k 'not test_value'
=================================== test session starts ====================================
platform win32 -- Python 3.10.5, pytest-7.1.2, pluggy-1.0.0
rootdir: C:\...\pytest-cli-fixtures, configfile: pytest.ini
plugins: cli-fixtures-1.0
collected 2 items / 1 deselected / 1 selected

example\test_something.py .                                                           [100%]

============================= 1 passed, 1 deselected in 0.02s ==============================

Provide CLI fixture argument

> pytest example --value=2
=================================== test session starts ====================================
platform win32 -- Python 3.10.5, pytest-7.1.2, pluggy-1.0.0
rootdir: C:\...\pytest-cli-fixtures, configfile: pytest.ini
plugins: cli-fixtures-1.0
collected 2 items

example\test_something.py ..                                                          [100%]

==================================== 2 passed in 0.03s =====================================