oslo-incubator/tests/unit/test_importutils.py
Dan Prince 33b12d3c18 Implement importutils.try_import.
Adds a new (simple) importutils.try_import function which
can return a module name or a default (by default this is None).

This should help clean up some of our

try:
    import foo
except...

blocks in modules.

This commit also drops the dependency on python-extras which is
no longer needed.

Fixes LP Bug #1099501.

Change-Id: I8591f79983bdad67a50d1aaae6dce8428dfce084
2013-01-14 12:54:43 -05:00

120 lines
5.0 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 OpenStack LLC.
# All Rights Reserved.
#
# 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 datetime
import sys
import unittest
from openstack.common import importutils
class ImportUtilsTest(unittest.TestCase):
# NOTE(jkoelker) There has GOT to be a way to test this. But mocking
# __import__ is the devil. Right now we just make
# sure we can import something from the stdlib
def test_import_class(self):
dt = importutils.import_class('datetime.datetime')
self.assertEqual(sys.modules['datetime'].datetime, dt)
def test_import_bad_class(self):
self.assertRaises(ImportError, importutils.import_class,
'lol.u_mad.brah')
def test_import_module(self):
dt = importutils.import_module('datetime')
self.assertEqual(sys.modules['datetime'], dt)
def test_import_object_optional_arg_not_present(self):
obj = importutils.import_object('tests.unit.fake.FakeDriver')
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_optional_arg_present(self):
obj = importutils.import_object('tests.unit.fake.FakeDriver',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_required_arg_not_present(self):
# arg 1 isn't optional here
self.assertRaises(TypeError, importutils.import_object,
'tests.unit.fake.FakeDriver2')
def test_import_object_required_arg_present(self):
obj = importutils.import_object('tests.unit.fake.FakeDriver2',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver2')
# namespace tests
def test_import_object_ns_optional_arg_not_present(self):
obj = importutils.import_object_ns('tests.unit', 'fake.FakeDriver')
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_ns_optional_arg_present(self):
obj = importutils.import_object_ns('tests.unit', 'fake.FakeDriver',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_ns_required_arg_not_present(self):
# arg 1 isn't optional here
self.assertRaises(TypeError, importutils.import_object_ns,
'tests.unit', 'fake.FakeDriver2')
def test_import_object_ns_required_arg_present(self):
obj = importutils.import_object_ns('tests.unit', 'fake.FakeDriver2',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver2')
# namespace tests
def test_import_object_ns_full_optional_arg_not_present(self):
obj = importutils.import_object_ns('tests.unit2',
'tests.unit.fake.FakeDriver')
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_ns_full_optional_arg_present(self):
obj = importutils.import_object_ns('tests.unit2',
'tests.unit.fake.FakeDriver',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver')
def test_import_object_ns_full_required_arg_not_present(self):
# arg 1 isn't optional here
self.assertRaises(TypeError, importutils.import_object_ns,
'tests.unit2', 'tests.unit.fake.FakeDriver2')
def test_import_object_ns_full_required_arg_present(self):
obj = importutils.import_object_ns('tests.unit2',
'tests.unit.fake.FakeDriver2',
first_arg=False)
self.assertTrue(obj.__class__.__name__, 'FakeDriver2')
def test_import_object(self):
dt = importutils.import_object('datetime.time')
self.assertTrue(isinstance(dt, sys.modules['datetime'].time))
def test_import_object_with_args(self):
dt = importutils.import_object('datetime.datetime', 2012, 4, 5)
self.assertTrue(isinstance(dt, sys.modules['datetime'].datetime))
self.assertEqual(dt, datetime.datetime(2012, 4, 5))
def test_try_import(self):
dt = importutils.try_import('datetime')
self.assertEqual(sys.modules['datetime'], dt)
def test_try_import_returns_default(self):
foo = importutils.try_import('foo.bar')
self.assertEqual(None, foo)