Fetch command line argument and assign it to global variable using pytest

Question

Have to fetch the command line arguments and assign them to global variables in the python script under nontest modules using a pytest.

Example Code:

# conftest.py
def pytest_addoption(parser):
    parser.addoption("--name", action="store", default="default name")

# test_sample.py
import pytest

@pytest.fixture
def name(req):
    return req.getoption("name")

# Here, I require the command line argument assigned to a global variable "glob_name"
glob_name = name

foo="""
def test_"""+glob_name+"""():
    print("Inside test function with a global name")
"""
exec(foo)

Command Used:

pytest -q -s test_sample.py --name google

Error occurred:

========================================================================================== ERRORS ==========================================================================================
_____________________________________________________________________________ ERROR collecting test_sample.py ______________________________________________________________________________
test_sample.py:10: in <module>
    def test_"""+glob_name+"""():
E   TypeError: cannot concatenate 'str' and 'function' objects
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
1 error in 0.12 seconds

Expected Output:

It should have to append the str "google" to the test function name and have to execute that function.

I would appreciate it if anyone can revert back with a solution for the above-mentioned issue.

pytest has an ability to select a specific test. https://docs.pytest.org/en/stable/usage.html#specifying-tests-selecting-tests — Alexander Volkovsky, Jun 18 '21 at 05:18
Is this of some help? https://stackoverflow.com/a/42145604/11246056 — Laurent, Jun 18 '21 at 05:59

score 1 · Accepted Answer · answered Jun 18 '21 at 07:12

To achieve what you are asking require us to use two hooks at same time.

pytest_generate_tests : To implement your own parametrization scheme.
pytest_collection_modifyitems : To rename based on your requirement.

You can use below code for same

conftest.py

import pytest


def pytest_addoption(parser):
    parser.addoption("--name", action="store", default="default name")


@pytest.fixture(scope='session')
def get_name(request):
    return request.config.getoption("--name")


def pytest_generate_tests(metafunc):
    if "get_name" in metafunc.fixturenames:
        if metafunc.config.getoption("name"):
            param = str(metafunc.config.getoption("name"))
        else:
            param = "default"
        metafunc.parametrize("get_name", [param])


def pytest_collection_modifyitems(items):
    for item in items:
        # check that we are altering a test named `test_run_name`
        # and it accepts the `get_name` arg
        if item.originalname == 'test_run_name' and 'get_name' in item.fixturenames:
            item._nodeid = item.nodeid.replace(']', '').replace('run_name[', '')

test_sample.py

def test_run_name(get_name):
    print("Inside test function with a global name {}".format(get_name))
    assert True

Run using cmd

pytest -v -s test_sample.py --name google

Output in Console:

Thank you alpha89. It is working with this code. Is it possible to pass multiple arguments at once and execute the test function with all of them? — user6677473, Jun 19 '21 at 10:17

Fetch command line argument and assign it to global variable using pytest

1 Answers1