1 files changed, 52 insertions, 0 deletions
diff --git a/nova/tests/unit/test_filesystem.py b/nova/tests/unit/test_filesystem.py
new file mode 100644
index 0000000000..85f16157ee
--- /dev/null
+++ b/nova/tests/unit/test_filesystem.py
@@ -0,0 +1,52 @@
+#    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 os
+from unittest import mock
+
+from nova import exception
+from nova import filesystem
+from nova import test
+
+
+class TestFSCommon(test.NoDBTestCase):
+
+    def test_read_sys(self):
+        open_mock = mock.mock_open(read_data='bar')
+        with mock.patch('builtins.open', open_mock) as m_open:
+            self.assertEqual('bar', filesystem.read_sys('foo'))
+        expected_path = os.path.join(filesystem.SYS, 'foo')
+        m_open.assert_called_once_with(expected_path, mode='r')
+
+    def test_read_sys_error(self):
+        with mock.patch('builtins.open',
+                        side_effect=OSError('error')) as m_open:
+            self.assertRaises(exception.FileNotFound,
+                              filesystem.read_sys, 'foo')
+        expected_path = os.path.join(filesystem.SYS, 'foo')
+        m_open.assert_called_once_with(expected_path, mode='r')
+
+    def test_write_sys(self):
+        open_mock = mock.mock_open()
+        with mock.patch('builtins.open', open_mock) as m_open:
+            self.assertIsNone(filesystem.write_sys('foo', 'bar'))
+        expected_path = os.path.join(filesystem.SYS, 'foo')
+        m_open.assert_called_once_with(expected_path, mode='w')
+        open_mock().write.assert_called_once_with('bar')
+
+    def test_write_sys_error(self):
+        with mock.patch('builtins.open',
+                        side_effect=OSError('fake_error')) as m_open:
+            self.assertRaises(exception.FileNotFound,
+                              filesystem.write_sys, 'foo', 'bar')
+        expected_path = os.path.join(filesystem.SYS, 'foo')
+        m_open.assert_called_once_with(expected_path, mode='w')