Source code for keystone.tests.unit.common.test_injection

# Copyright 2012 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import uuid

from keystone.common import dependency
from keystone.tests import unit


[docs]class TestDependencyInjection(unit.BaseTestCase):
[docs] def setUp(self): super(TestDependencyInjection, self).setUp() dependency.reset() self.addCleanup(dependency.reset)
[docs] def test_dependency_injection(self): class Interface(object): def do_work(self): assert False @dependency.provider('first_api') class FirstImplementation(Interface): def do_work(self): return True @dependency.provider('second_api') class SecondImplementation(Interface): def do_work(self): return True @dependency.requires('first_api', 'second_api') class Consumer(object): def do_work_with_dependencies(self): assert self.first_api.do_work() assert self.second_api.do_work() # initialize dependency providers first_api = FirstImplementation() second_api = SecondImplementation() # ... sometime later, initialize a dependency consumer consumer = Consumer() # the expected dependencies should be available to the consumer self.assertIs(consumer.first_api, first_api) self.assertIs(consumer.second_api, second_api) self.assertIsInstance(consumer.first_api, Interface) self.assertIsInstance(consumer.second_api, Interface) consumer.do_work_with_dependencies()
[docs] def test_dependency_provider_configuration(self): @dependency.provider('api') class Configurable(object): def __init__(self, value=None): self.value = value def get_value(self): return self.value @dependency.requires('api') class Consumer(object): def get_value(self): return self.api.get_value() # initialize dependency providers api = Configurable(value=True) # ... sometime later, initialize a dependency consumer consumer = Consumer() # the expected dependencies should be available to the consumer self.assertIs(consumer.api, api) self.assertIsInstance(consumer.api, Configurable) self.assertTrue(consumer.get_value())
[docs] def test_dependency_consumer_configuration(self): @dependency.provider('api') class Provider(object): def get_value(self): return True @dependency.requires('api') class Configurable(object): def __init__(self, value=None): self.value = value def get_value(self): if self.value: return self.api.get_value() # initialize dependency providers api = Provider() # ... sometime later, initialize a dependency consumer consumer = Configurable(value=True) # the expected dependencies should be available to the consumer self.assertIs(consumer.api, api) self.assertIsInstance(consumer.api, Provider) self.assertTrue(consumer.get_value())
[docs] def test_inherited_dependency(self): class Interface(object): def do_work(self): assert False @dependency.provider('first_api') class FirstImplementation(Interface): def do_work(self): return True @dependency.provider('second_api') class SecondImplementation(Interface): def do_work(self): return True @dependency.requires('first_api') class ParentConsumer(object): def do_work_with_dependencies(self): assert self.first_api.do_work() @dependency.requires('second_api') class ChildConsumer(ParentConsumer): def do_work_with_dependencies(self): assert self.second_api.do_work() super(ChildConsumer, self).do_work_with_dependencies() # initialize dependency providers first_api = FirstImplementation() second_api = SecondImplementation() # ... sometime later, initialize a dependency consumer consumer = ChildConsumer() # dependencies should be naturally inherited self.assertEqual( set(['first_api']), ParentConsumer._dependencies) self.assertEqual( set(['first_api', 'second_api']), ChildConsumer._dependencies) self.assertEqual( set(['first_api', 'second_api']), consumer._dependencies) # the expected dependencies should be available to the consumer self.assertIs(consumer.first_api, first_api) self.assertIs(consumer.second_api, second_api) self.assertIsInstance(consumer.first_api, Interface) self.assertIsInstance(consumer.second_api, Interface) consumer.do_work_with_dependencies()
[docs] def test_unresolvable_dependency(self): @dependency.requires(uuid.uuid4().hex) class Consumer(object): pass def for_test(): Consumer() dependency.resolve_future_dependencies() self.assertRaises(dependency.UnresolvableDependencyException, for_test)
[docs] def test_circular_dependency(self): p1_name = uuid.uuid4().hex p2_name = uuid.uuid4().hex @dependency.provider(p1_name) @dependency.requires(p2_name) class P1(object): pass @dependency.provider(p2_name) @dependency.requires(p1_name) class P2(object): pass p1 = P1() p2 = P2() dependency.resolve_future_dependencies() self.assertIs(getattr(p1, p2_name), p2) self.assertIs(getattr(p2, p1_name), p1)
[docs] def test_reset(self): # Can reset the registry of providers. p_id = uuid.uuid4().hex @dependency.provider(p_id) class P(object): pass p_inst = P() self.assertIs(dependency.get_provider(p_id), p_inst) dependency.reset() self.assertFalse(dependency._REGISTRY)
[docs] def test_get_provider(self): # Can get the instance of a provider using get_provider provider_name = uuid.uuid4().hex @dependency.provider(provider_name) class P(object): pass provider_instance = P() retrieved_provider_instance = dependency.get_provider(provider_name) self.assertIs(provider_instance, retrieved_provider_instance)
[docs] def test_get_provider_not_provided_error(self): # If no provider and provider is required then fails. provider_name = uuid.uuid4().hex self.assertRaises(KeyError, dependency.get_provider, provider_name)
[docs] def test_get_provider_not_provided_optional(self): # If no provider and provider is optional then returns None. provider_name = uuid.uuid4().hex self.assertIsNone(dependency.get_provider(provider_name, dependency.GET_OPTIONAL))