Merge "Add module for loading specific classes"

4 files changed, 223 insertions, 0 deletions

diff --git a/nova/tests/fake_loadables/__init__.py b/nova/tests/fake_loadables/__init__.py
new file mode 100644
index 000000000..824243347
--- /dev/null
+++ b/nova/tests/fake_loadables/__init__.py
@@ -0,0 +1,27 @@
+# Copyright 2012 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.
+"""
+Fakes For Loadable class handling.
+"""
+
+from nova import loadables
+
+
+class FakeLoadable(object):
+    pass
+
+
+class FakeLoader(loadables.BaseLoader):
+    def __init__(self):
+        super(FakeLoader, self).__init__(FakeLoadable)
diff --git a/nova/tests/fake_loadables/fake_loadable1.py b/nova/tests/fake_loadables/fake_loadable1.py
new file mode 100644
index 000000000..58f9704b3
--- /dev/null
+++ b/nova/tests/fake_loadables/fake_loadable1.py
@@ -0,0 +1,44 @@
+# Copyright 2012 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.
+"""
+Fake Loadable subclasses module #1
+"""
+
+from nova.tests import fake_loadables
+
+
+class FakeLoadableSubClass1(fake_loadables.FakeLoadable):
+    pass
+
+
+class FakeLoadableSubClass2(fake_loadables.FakeLoadable):
+    pass
+
+
+class _FakeLoadableSubClass3(fake_loadables.FakeLoadable):
+    """Classes beginning with '_' will be ignored."""
+    pass
+
+
+class FakeLoadableSubClass4(object):
+    """Not a correct subclass."""
+
+
+def return_valid_classes():
+    return [FakeLoadableSubClass1, FakeLoadableSubClass2]
+
+
+def return_invalid_classes():
+    return [FakeLoadableSubClass1, _FakeLoadableSubClass3,
+            FakeLoadableSubClass4]
diff --git a/nova/tests/fake_loadables/fake_loadable2.py b/nova/tests/fake_loadables/fake_loadable2.py
new file mode 100644
index 000000000..3e365effc
--- /dev/null
+++ b/nova/tests/fake_loadables/fake_loadable2.py
@@ -0,0 +1,39 @@
+# Copyright 2012 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.
+"""
+Fake Loadable subclasses module #2
+"""
+
+from nova.tests import fake_loadables
+
+
+class FakeLoadableSubClass5(fake_loadables.FakeLoadable):
+    pass
+
+
+class FakeLoadableSubClass6(fake_loadables.FakeLoadable):
+    pass
+
+
+class _FakeLoadableSubClass7(fake_loadables.FakeLoadable):
+    """Classes beginning with '_' will be ignored."""
+    pass
+
+
+class FakeLoadableSubClass8(BaseException):
+    """Not a correct subclass."""
+
+
+def return_valid_class():
+    return [FakeLoadableSubClass6]
diff --git a/nova/tests/test_loadables.py b/nova/tests/test_loadables.py
new file mode 100644
index 000000000..6d16b9fa8
--- /dev/null
+++ b/nova/tests/test_loadables.py
@@ -0,0 +1,113 @@
+# Copyright 2012 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.
+"""
+Tests For Loadable class handling.
+"""
+
+from nova import exception
+from nova import test
+from nova.tests import fake_loadables
+
+
+class LoadablesTestCase(test.TestCase):
+    def setUp(self):
+        super(LoadablesTestCase, self).setUp()
+        self.fake_loader = fake_loadables.FakeLoader()
+        # The name that we imported above for testing
+        self.test_package = 'nova.tests.fake_loadables'
+
+    def test_loader_init(self):
+        self.assertEqual(self.fake_loader.package, self.test_package)
+        # Test the path of the module
+        ending_path = '/' + self.test_package.replace('.', '/')
+        self.assertTrue(self.fake_loader.path.endswith(ending_path))
+        self.assertEqual(self.fake_loader.loadable_cls_type,
+                         fake_loadables.FakeLoadable)
+
+    def _compare_classes(self, classes, expected):
+        class_names = [cls.__name__ for cls in classes]
+        self.assertEqual(set(class_names), set(expected))
+
+    def test_get_all_classes(self):
+        classes = self.fake_loader.get_all_classes()
+        expected_class_names = ['FakeLoadableSubClass1',
+                                'FakeLoadableSubClass2',
+                                'FakeLoadableSubClass5',
+                                'FakeLoadableSubClass6']
+        self._compare_classes(classes, expected_class_names)
+
+    def test_get_matching_classes(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.FakeLoadableSubClass1',
+                        prefix + '.fake_loadable2.FakeLoadableSubClass5']
+        classes = self.fake_loader.get_matching_classes(test_classes)
+        expected_class_names = ['FakeLoadableSubClass1',
+                                'FakeLoadableSubClass5']
+        self._compare_classes(classes, expected_class_names)
+
+    def test_get_matching_classes_with_underscore(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.FakeLoadableSubClass1',
+                        prefix + '.fake_loadable2._FakeLoadableSubClass7']
+        self.assertRaises(exception.ClassNotFound,
+                          self.fake_loader.get_matching_classes,
+                          test_classes)
+
+    def test_get_matching_classes_with_wrong_type1(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.FakeLoadableSubClass4',
+                        prefix + '.fake_loadable2.FakeLoadableSubClass5']
+        self.assertRaises(exception.ClassNotFound,
+                          self.fake_loader.get_matching_classes,
+                          test_classes)
+
+    def test_get_matching_classes_with_wrong_type2(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.FakeLoadableSubClass1',
+                        prefix + '.fake_loadable2.FakeLoadableSubClass8']
+        self.assertRaises(exception.ClassNotFound,
+                          self.fake_loader.get_matching_classes,
+                          test_classes)
+
+    def test_get_matching_classes_with_one_function(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.return_valid_classes',
+                        prefix + '.fake_loadable2.FakeLoadableSubClass5']
+        classes = self.fake_loader.get_matching_classes(test_classes)
+        expected_class_names = ['FakeLoadableSubClass1',
+                                'FakeLoadableSubClass2',
+                                'FakeLoadableSubClass5']
+        self._compare_classes(classes, expected_class_names)
+
+    def test_get_matching_classes_with_two_functions(self):
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.return_valid_classes',
+                        prefix + '.fake_loadable2.return_valid_class']
+        classes = self.fake_loader.get_matching_classes(test_classes)
+        expected_class_names = ['FakeLoadableSubClass1',
+                                'FakeLoadableSubClass2',
+                                'FakeLoadableSubClass6']
+        self._compare_classes(classes, expected_class_names)
+
+    def test_get_matching_classes_with_function_including_invalids(self):
+        # When using a method, no checking is done on valid classes.
+        prefix = self.test_package
+        test_classes = [prefix + '.fake_loadable1.return_invalid_classes',
+                        prefix + '.fake_loadable2.return_valid_class']
+        classes = self.fake_loader.get_matching_classes(test_classes)
+        expected_class_names = ['FakeLoadableSubClass1',
+                                '_FakeLoadableSubClass3',
+                                'FakeLoadableSubClass4',
+                                'FakeLoadableSubClass6']
+        self._compare_classes(classes, expected_class_names)