diff --git a/oslotest/modules.py b/oslotest/modules.py new file mode 100644 index 0000000..f453b17 --- /dev/null +++ b/oslotest/modules.py @@ -0,0 +1,50 @@ +# 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 sys + +import fixtures + + +class DisableModuleFixture(fixtures.Fixture): + """A fixture to provide support for unloading/disabling modules.""" + + def __init__(self, module, *args, **kwargs): + super(DisableModuleFixture, self).__init__(*args, **kwargs) + self.module = module + + def setUp(self): + """Ensure ImportError for the specified module.""" + super(DisableModuleFixture, self).setUp() + + cleared_modules = {} + + for name in list(sys.modules.keys()): + if name == self.module or name.startswith(self.module + '.'): + cleared_modules[name] = sys.modules.pop(name) + + finder = _NoModuleFinder(self.module) + sys.meta_path.insert(0, finder) + + self.addCleanup(sys.meta_path.remove, finder) + self.addCleanup(sys.modules.update, cleared_modules) + + +class _NoModuleFinder(object): + """Disallow further imports of 'module'.""" + + def __init__(self, module): + self.module = module + + def find_module(self, fullname, path): + if fullname == self.module or fullname.startswith(self.module + '.'): + raise ImportError diff --git a/oslotest/tests/unit/test_modules.py b/oslotest/tests/unit/test_modules.py new file mode 100644 index 0000000..f457265 --- /dev/null +++ b/oslotest/tests/unit/test_modules.py @@ -0,0 +1,28 @@ +# 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. + +from oslotest import base +from oslotest import modules + + +class CreateDisableModuleTest(base.BaseTestCase): + + def test_disable_module(self): + + s = __import__('sys') + self.assertTrue(s) + + with modules.DisableModuleFixture('sys'): + self.assertRaises(ImportError, __import__, 'sys') + + s = __import__('sys') + self.assertTrue(s)