Improve unit test coverage for cmd/api.py

Add new unit tests for cmd/api.py.
Increase the coverage for cmd/api.py from 0 to 100%.

Change-Id: I2409ed9ff11b55ae761d4f0b5768f65ca1bec9e3
Partial-Bug: #1511667

magnum/tests/unit/cmd/test_api.py

@@ -0,0 +1,38 @@
+# Copyright 2016 - Fujitsu, Ltd.
+#
+#    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 mock
+
+from magnum.cmd import api
+from magnum.tests import base
+
+
+class TestMagnumAPI(base.TestCase):
+
+    # NOTE(hieulq): need to mock MagnumObject, otherwise other test cases
+    # will be failed because of setting wrong ovo indirection api
+    @mock.patch('magnum.objects.base.MagnumObject')
+    @mock.patch('wsgiref.simple_server.make_server')
+    @mock.patch.object(api, 'api_app')
+    @mock.patch('magnum.common.service.prepare_service')
+    def test_api(self, mock_prep, mock_app, mock_make, mock_base):
+        api.main()
+
+        app = mock_app.load_app.return_value
+        server = mock_make.return_value
+        mock_prep.assert_called_once_with(mock.ANY)
+        mock_app.load_app.assert_called_once_with()
+        mock_make.assert_called_once_with(base.CONF.api.host,
+                                          base.CONF.api.port, app)
+        server.serve_forever.assert_called_once_with()