freeipa/tests/test_xmlrpc/test_baseldap_plugin.py
Petr Viktorin 9960149e3f Rework the CallbackInterface
Fix several problems with the callback interface:
- Automatically registered callbacks (i.e. methods named
    exc_callback, pre_callback etc) were registered on every
    instantiation.
    Fix: Do not register callbacks in __init__; instead return the
    method when asked for it.
- The calling code had to distinguish between bound methods and
    plain functions by checking the 'im_self' attribute.
    Fix: Always return the "default" callback as an unbound method.
    Registered callbacks now always take the extra `self` argument,
    whether they happen to be bound methods or not.
    Calling code now always needs to pass the `self` argument.
- Did not work well with inheritance: due to the fact that Python
    looks up missing attributes in superclasses, callbacks could
    get attached to a superclass if it was instantiated early enough. *
    Fix: Instead of attribute lookup, use a dictionary with class keys.
- The interface included the callback types, which are LDAP-specific.
    Fix: Create generic register_callback and get_callback mehods,
    move LDAP-specific code to BaseLDAPCommand

Update code that calls the callbacks.
Add tests.
Remove lint exceptions for CallbackInterface.

* https://fedorahosted.org/freeipa/ticket/2674
2012-06-14 11:09:43 +02:00

160 lines
5.2 KiB
Python

# Authors:
# Petr Viktorin <pviktori@redhat.com>
#
# Copyright (C) 2012 Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
Test the `ipalib.plugins.baseldap` module.
"""
from ipalib import errors
from ipalib.plugins import baseldap
def test_exc_wrapper():
"""Test the CallbackInterface._exc_wrapper helper method"""
handled_exceptions = []
class test_callback(baseldap.BaseLDAPCommand):
"""Fake IPA method"""
def test_fail(self):
self._exc_wrapper([], {}, self.fail)(1, 2, a=1, b=2)
def fail(self, *args, **kwargs):
assert args == (1, 2)
assert kwargs == dict(a=1, b=2)
raise errors.ExecutionError('failure')
instance = test_callback()
# Test with one callback first
@test_callback.register_exc_callback
def handle_exception(self, keys, options, e, call_func, *args, **kwargs):
assert args == (1, 2)
assert kwargs == dict(a=1, b=2)
handled_exceptions.append(type(e))
instance.test_fail()
assert handled_exceptions == [errors.ExecutionError]
# Test with another callback added
handled_exceptions = []
def dont_handle(self, keys, options, e, call_func, *args, **kwargs):
assert args == (1, 2)
assert kwargs == dict(a=1, b=2)
handled_exceptions.append(None)
raise e
test_callback.register_exc_callback(dont_handle, first=True)
instance.test_fail()
assert handled_exceptions == [None, errors.ExecutionError]
def test_callback_registration():
class callbacktest_base(baseldap.CallbackInterface):
_callback_registry = dict(test={})
def test_callback(self, param):
messages.append(('Base test_callback', param))
def registered_callback(self, param):
messages.append(('Base registered callback', param))
callbacktest_base.register_callback('test', registered_callback)
class SomeClass(object):
def registered_callback(self, command, param):
messages.append(('Registered callback from another class', param))
callbacktest_base.register_callback('test', SomeClass().registered_callback)
class callbacktest_subclass(callbacktest_base):
pass
def subclass_callback(self, param):
messages.append(('Subclass registered callback', param))
callbacktest_subclass.register_callback('test', subclass_callback)
messages = []
instance = callbacktest_base()
for callback in instance.get_callbacks('test'):
callback(instance, 42)
assert messages == [
('Base test_callback', 42),
('Base registered callback', 42),
('Registered callback from another class', 42)]
messages = []
instance = callbacktest_subclass()
for callback in instance.get_callbacks('test'):
callback(instance, 42)
assert messages == [
('Base test_callback', 42),
('Subclass registered callback', 42)]
def test_exc_callback_registration():
messages = []
class callbacktest_base(baseldap.BaseLDAPCommand):
"""A method superclass with an exception callback"""
def exc_callback(self, keys, options, exc, call_func, *args, **kwargs):
"""Let the world know we saw the error, but don't handle it"""
messages.append('Base exc_callback')
raise exc
def test_fail(self):
"""Raise a handled exception"""
try:
self._exc_wrapper([], {}, self.fail)(1, 2, a=1, b=2)
except Exception:
pass
def fail(self, *args, **kwargs):
"""Raise an error"""
raise errors.ExecutionError('failure')
base_instance = callbacktest_base()
class callbacktest_subclass(callbacktest_base):
pass
@callbacktest_subclass.register_exc_callback
def exc_callback(self, keys, options, exc, call_func, *args, **kwargs):
"""Subclass's private exception callback"""
messages.append('Subclass registered callback')
raise exc
subclass_instance = callbacktest_subclass()
# Make sure exception in base class is only handled by the base class
base_instance.test_fail()
assert messages == ['Base exc_callback']
@callbacktest_base.register_exc_callback
def exc_callback(self, keys, options, exc, call_func, *args, **kwargs):
"""Callback on super class; doesn't affect the subclass"""
messages.append('Superclass registered callback')
raise exc
# Make sure exception in subclass is only handled by both
messages = []
subclass_instance.test_fail()
assert messages == ['Base exc_callback', 'Subclass registered callback']