def getfixtureinfo(
        self,
        node: nodes.Item,
        func: Callable[..., object] | None,
        cls: type | None,
    ) -> FuncFixtureInfo:
        """Calculate the :class:`FuncFixtureInfo` for an item.

        If ``func`` is None, or if the item sets an attribute
        ``nofuncargs = True``, then ``func`` is not examined at all.

        :param node:
            The item requesting the fixtures.
        :param func:
            The item's function.
        :param cls:
            If the function is a method, the method's class.
        """
        if func is not None and not getattr(node, "nofuncargs", False):
            argnames = getfuncargnames(func, name=node.name, cls=cls)
        else:
            argnames = ()
        usefixturesnames = self._getusefixturesnames(node)
        autousenames = self._getautousenames(node)
        initialnames = deduplicate_names(autousenames, usefixturesnames, argnames)

        direct_parametrize_args = _get_direct_parametrize_args(node)

        names_closure, arg2fixturedefs = self.getfixtureclosure(
            parentnode=node,
            initialnames=initialnames,
            ignore_args=direct_parametrize_args,
        )

        return FuncFixtureInfo(argnames, initialnames, names_closure, arg2fixturedefs)
Calculate the :class:`FuncFixtureInfo` for an item.

        If ``func`` is None, or if the item sets an attribute
        ``nofuncargs = True``, then ``func`` is not examined at all.

        :param node:
            The item requesting the fixtures.
        :param func:
            The item's function.
        :param cls:
            If the function is a method, the method's class.
        
src/_pytest/fixtures.py