Create Timeout wrapper fixture

Add a fixture to replace the code in the test base class that was looking
at OS_TEST_TIMEOUT and setting up a fixtures.Timeout instance.

Blueprint oslotest-refactor-test-base-class

Change-Id: I0432ac28772395be15db539f3797b257eb8933ca

doc/source/api.rst

@@ -22,3 +22,10 @@ oslotest.moxstubout
 
 .. automodule:: oslotest.moxstubout
    :members:
+
+oslotest.timeout
+================
+
+.. automodule:: oslotest.timeout
+   :members:
+   :special-members:

oslotest/base.py

@@ -20,6 +20,8 @@ import os
 import tempfile
 
 import fixtures
+from oslotest import timeout
+
 import six
 from six.moves import mock
 import testtools
@@ -96,14 +98,7 @@ class BaseTestCase(testtools.TestCase):
         self.useFixture(fixtures.TempHomeDir())
 
     def _set_timeout(self):
-        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
-        try:
-            test_timeout = int(test_timeout)
-        except ValueError:
-            # If timeout value is invalid do not set a timeout.
-            test_timeout = 0
-        if test_timeout > 0:
-            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
+        self.useFixture(timeout.Timeout())
 
     def _fake_output(self):
         if os.environ.get('OS_STDOUT_CAPTURE') in _TRUE_VALUES:

oslotest/timeout.py

@@ -0,0 +1,34 @@
+# 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 fixtures
+
+import os
+
+
+class Timeout(fixtures.Fixture):
+    """Set the maximum length of time for the test to run.
+
+    Uses OS_TEST_TIMEOUT to get the timeout.
+
+    """
+
+    def setUp(self):
+        super(Timeout, self).setUp()
+        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
+        try:
+            test_timeout = int(test_timeout)
+        except ValueError:
+            # If timeout value is invalid do not set a timeout.
+            test_timeout = 0
+        if test_timeout > 0:
+            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))

tests/unit/test_base.py

@@ -33,7 +33,7 @@ class TestBaseTestCase(testtools.TestCase):
             pass
 
     @mock.patch('os.environ.get')
-    @mock.patch.object(FakeTestCase, 'useFixture')
+    @mock.patch('oslotest.timeout.Timeout.useFixture')
     @mock.patch('fixtures.Timeout')
     def test_timeout(self, fixture_timeout_mock, fixture_mock, env_get_mock):
         env_get_mock.return_value = 1

tests/unit/test_timeout.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+
+#    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
+import testtools
+
+from oslotest import timeout
+
+
+class TimeoutTestCase(testtools.TestCase):
+
+    @mock.patch('os.environ.get')
+    @mock.patch.object(timeout.Timeout, 'useFixture')
+    @mock.patch('fixtures.Timeout')
+    def test_timeout(self, fixture_timeout_mock, fixture_mock, env_get_mock):
+        env_get_mock.return_value = 1
+        tc = timeout.Timeout()
+        tc.setUp()
+        env_get_mock.assert_called_once_with('OS_TEST_TIMEOUT', 0)
+        fixture_timeout_mock.assert_called_once_with(1, gentle=True)
+        self.assertEqual(fixture_mock.call_count, 1)
+
+    @mock.patch('os.environ.get')
+    @mock.patch.object(timeout.Timeout, 'useFixture')
+    @mock.patch('fixtures.Timeout')
+    def test_no_timeout(self, fixture_timeout_mock, fixture_mock,
+                        env_get_mock):
+        # Returning 0 means we don't install the timeout
+        env_get_mock.return_value = 0
+        tc = timeout.Timeout()
+        tc.setUp()
+        env_get_mock.assert_called_once_with('OS_TEST_TIMEOUT', 0)
+        self.assertEqual(fixture_timeout_mock.call_count, 0)
+        self.assertEqual(fixture_mock.call_count, 0)