stevedore/stevedore/tests/test_driver.py

90 lines
3.2 KiB
Python

# 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.
"""Tests for stevedore.extension
"""
import pkg_resources
from stevedore import driver
from stevedore import exception
from stevedore import extension
from stevedore.tests import test_extension
from stevedore.tests import utils
class TestCallback(utils.TestCase):
def test_detect_plugins(self):
em = driver.DriverManager('stevedore.test.extension', 't1')
names = sorted(em.names())
self.assertEqual(names, ['t1'])
def test_call(self):
def invoke(ext, *args, **kwds):
return (ext.name, args, kwds)
em = driver.DriverManager('stevedore.test.extension', 't1')
result = em(invoke, 'a', b='C')
self.assertEqual(result, ('t1', ('a',), {'b': 'C'}))
def test_driver_property_not_invoked_on_load(self):
em = driver.DriverManager('stevedore.test.extension', 't1',
invoke_on_load=False)
d = em.driver
self.assertIs(d, test_extension.FauxExtension)
def test_driver_property_invoked_on_load(self):
em = driver.DriverManager('stevedore.test.extension', 't1',
invoke_on_load=True)
d = em.driver
self.assertIsInstance(d, test_extension.FauxExtension)
def test_no_drivers(self):
try:
driver.DriverManager('stevedore.test.extension.none', 't1')
except exception.NoMatches as err:
self.assertIn("No 'stevedore.test.extension.none' driver found",
str(err))
def test_bad_driver(self):
try:
driver.DriverManager('stevedore.test.extension', 'e2')
except ImportError:
pass
else:
self.assertEqual(False, "No error raised")
def test_multiple_drivers(self):
# The idea for this test was contributed by clayg:
# https://gist.github.com/clayg/6311348
extensions = [
extension.Extension(
'backend',
pkg_resources.EntryPoint.parse('backend = pkg1:driver'),
'pkg backend',
None,
),
extension.Extension(
'backend',
pkg_resources.EntryPoint.parse('backend = pkg2:driver'),
'pkg backend',
None,
),
]
try:
dm = driver.DriverManager.make_test_instance(extensions[0])
# Call the initialization code that verifies the extension
dm._init_plugins(extensions)
except exception.MultipleMatches as err:
self.assertIn("Multiple", str(err))
else:
self.fail('Should have had an error')