Method recursive_issubclass

crates/vm/src/protocol/object.rs:499–523

(&self, cls: &Self, vm: &VirtualMachine)

    }

    fn recursive_issubclass(&self, cls: &Self, vm: &VirtualMachine) -> PyResult<bool> {
        // Fast path for both being types (matches CPython's PyType_Check)
        if let Some(cls) = PyType::check(cls)
            && let Some(derived) = PyType::check(self)
        {
            // PyType_IsSubtype equivalent
            return Ok(derived.is_subtype(cls));
        }
        // Check if derived is a class
        self.check_class(vm, || {
            format!("issubclass() arg 1 must be a class, not {}", self.class())
        })?;

        // Check if cls is a class, tuple, or union (matches CPython's order and message)
        if !cls.class().is(vm.ctx.types.union_type) {
            cls.check_class(vm, || {
                format!(
                    "issubclass() arg 2 must be a class, a tuple of classes, or a union, not {}",
                    cls.class()
                )
            })?;
        }

        self.abstract_issubclass(cls, vm)
    }

    /// Real issubclass check without going through __subclasscheck__
    /// This is equivalent to CPython's _PyObject_RealIsSubclass which just calls recursive_issubclass