基于命令行参数的参数化pytest函数

Question

I'm doing some selenium testing in Python, and I'm trying to set up my conftest.py to generate a new webdriver fixture that persists for the entire session, for each of the desired capabilities. The list of desired capabilities objects is specified via a YAML file, the path to which is specified at the command line.

Here's a super whittled down version of my conftest.py to illustrate what I have so far:

def pytest_addoption(parser):
    parser.addoption("-C", "--capabilities", action="store", default="capabilities.yaml")

def pytest_generate_tests(metafunc):
    if 'desired_capabilities' in metafunc.fixturenames:
        capabilities_file = metafunc.config.option.capabilities
        metafunc.parametrize('desired_capabilities', yaml.load(capabilities_file))

@pytest.fixture(scope="session")
def webdriver(desired_capabilities):
    # desired_capabilities should take on the different values of the list in the YAML file
    driver = util.create_webdriver(desired_capabilities)

But with this code, I am getting a whole bunch of ScopeMismatchError seg, ScopeMismatchError: You tried to access the 'function' scoped fixture 'desired_capabilities' with a 'session' scoped request object, involved factories (... omitted)

How do I achieve this sort of thing?

Answer 1

I think I've figured it out. The issue was that I needed to add scope="session" to the keyword arguments of the call to parametrize .