fix: default value not covered by parameters passed through feature file

[yunxuo]

Describe the bug
when given multi description for step as below code

@given('a user with username')
@given(parsers.parse('a user with username {username}'))
@given(parsers.parse('a user with username {username} and password {password}'))
def create_user(user, username="defaultuser", password='defaultpassword'):
    user['username'] = username
    user['password'] = password

and pass parameters from feature file in Scenario Outline

Scenario Outline: User login
    Given a user with username <username> and password <password>
    When the user logs in with username <username> and password <password>
    Then the login should be <result>

    Examples:
      | username | password    | result  |
      | testuser | password123 | success |

Parameters username, password parameters passed through feature file cannot take effect.
The default values in def are always used。
in above case, the result is

user = {
    'username': 'defaultuser',
    'password': 'defaultpassword'
}

see also:
#610 pr fix this problems
#512

[jsa34]

Thanks for the PR! Can we add a test for this?

[yunxuo]

Thanks for the PR! Can we add a test for this?

yes!

[jsa34]

I cannot see any changes? I was expecting the tests to be added

[yunxuo]

I cannot see any changes? I was expecting the tests to be added

sorry I'm late.
I have pushed a test case in commit, but I don't know if it meets the repository specifications.

[jsa34]

I tried locally, and noticed tests fail - there seems to be issues with some step args now.

Could you address these test failures?

It appears to be when the kwarg isn't an arg of the step

[yunxuo]

I tried locally, and noticed tests fail - there seems to be issues with some step args now.

Could you address these test failures?

It appears to be when the kwarg needs to exist but isn't an arg of the step

yes! when the kwarg needs to exist but isn't an arg of the step, so it will removed by following code

Do you mean the case I added failed？
in current pytest_bdd version, it will failed, but in this pr, will fix it

[jsa34]

No, on the existing tests.

I will invoke a run to report the tests that fail

[jsa34]

See failing tests:

https://github.com/pytest-dev/pytest-bdd/actions/runs/11854436082/job/33036622290?pr=737

[jsa34]

I took a look quickly to see if I could find a way to fix this and maintain the cases I mentioned, and came up with something like:

def _execute_step_function(
    request: FixtureRequest, scenario: Scenario, step: Step, context: StepFunctionContext
) -> None:
    """Execute step function."""
    __tracebackhide__ = True

    func_sig = signature(context.step_func)
    converters = context.converters

    def _get_parsed_arguments():
        """Parse and convert step arguments."""
        parsed_args = context.parser.parse_arguments(step.name)
        if parsed_args is None:
            raise ValueError(
                f"Unexpected `NoneType` returned from parse_arguments(...) in parser: {context.parser!r}"
            )
        kwargs = {}
        for arg, value in parsed_args.items():
            param = func_sig.parameters.get(arg)
            if param:
                if arg in converters:
                    value = converters[arg](value)
                kwargs[arg] = value
        return kwargs

    def _get_argument_values(kwargs):
        """Get default values or request fixture values for missing arguments."""
        for arg in get_args(context.step_func):
            if arg not in kwargs:
                param = func_sig.parameters.get(arg)
                if param:
                    if param.default != param.empty:
                        kwargs[arg] = param.default
                    else:
                        kwargs[arg] = request.getfixturevalue(arg)
        return kwargs

    kw = {
        "request": request,
        "feature": scenario.feature,
        "scenario": scenario,
        "step": step,
        "step_func": context.step_func,
        "step_func_args": {},
    }

    request.config.hook.pytest_bdd_before_step(**kw)

    try:
        # Use internal methods without passing redundant arguments
        kwargs = _get_parsed_arguments()

        if "datatable" in func_sig.parameters and step.datatable is not None:
            kwargs["datatable"] = step.datatable.raw()
        if "docstring" in func_sig.parameters and step.docstring is not None:
            kwargs["docstring"] = step.docstring

        kwargs = _get_argument_values(kwargs)

        kw["step_func_args"] = kwargs

        request.config.hook.pytest_bdd_before_step_call(**kw)

        return_value = call_fixture_func(fixturefunc=context.step_func, request=request, kwargs=kwargs)

    except Exception as exception:
        request.config.hook.pytest_bdd_step_error(exception=exception, **kw)
        raise

    if context.target_fixture is not None:
        inject_fixture(request, context.target_fixture, return_value)

    request.config.hook.pytest_bdd_after_step(**kw)

If this helps :)