Add initial unit test for tempest plugins

Add test for get_plugin_load_tests_tuple()

Partially implements bp external-plugin-interface

Change-Id: If441e4877f60c1b7e9a59692e7579b1c16e84c9d
diff --git a/tempest/tests/fake_tempest_plugin.py b/tempest/tests/fake_tempest_plugin.py
new file mode 100644
index 0000000..f718d0b
--- /dev/null
+++ b/tempest/tests/fake_tempest_plugin.py
@@ -0,0 +1,40 @@
+# Copyright (c) 2015 Deutsche Telekom AG
+# 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.
+
+from tempest.test_discover import plugins
+
+
+class FakePlugin(plugins.TempestPlugin):
+    expected_load_test = ["my/test/path", "/home/dir"]
+
+    def load_tests(self):
+        return self.expected_load_test
+
+    def register_opts(self, conf):
+        return
+
+    def get_opt_lists(self):
+        return []
+
+
+class FakeStevedoreObj(object):
+    obj = FakePlugin()
+
+    @property
+    def name(self):
+        return self._name
+
+    def __init__(self, name='Test1'):
+        self._name = name
diff --git a/tempest/tests/test_tempest_plugin.py b/tempest/tests/test_tempest_plugin.py
new file mode 100644
index 0000000..c07e98c
--- /dev/null
+++ b/tempest/tests/test_tempest_plugin.py
@@ -0,0 +1,44 @@
+# Copyright (c) 2015 Deutsche Telekom AG
+# 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.
+
+from tempest.test_discover import plugins
+from tempest.tests import base
+from tempest.tests import fake_tempest_plugin as fake_plugin
+
+
+class TestPluginDiscovery(base.TestCase):
+    def test_load_tests_with_one_plugin(self):
+        # we can't mock stevedore since it's a singleton and already executed
+        # during test discovery. So basically this test covers the plugin loop
+        # and the abstract plugin interface.
+        manager = plugins.TempestTestPluginManager()
+        fake_obj = fake_plugin.FakeStevedoreObj()
+        manager.ext_plugins = [fake_obj]
+        result = manager.get_plugin_load_tests_tuple()
+
+        self.assertEqual(fake_plugin.FakePlugin.expected_load_test,
+                         result[fake_obj.name])
+
+    def test_load_tests_with_two_plugins(self):
+        manager = plugins.TempestTestPluginManager()
+        obj1 = fake_plugin.FakeStevedoreObj('fake01')
+        obj2 = fake_plugin.FakeStevedoreObj('fake02')
+        manager.ext_plugins = [obj1, obj2]
+        result = manager.get_plugin_load_tests_tuple()
+
+        self.assertEqual(fake_plugin.FakePlugin.expected_load_test,
+                         result['fake01'])
+        self.assertEqual(fake_plugin.FakePlugin.expected_load_test,
+                         result['fake02'])