Fix ValueError in subunit_trace

When a subunit stream for a testcase doesn't contain start end
enddate, the duration can't be calculated which leads to a:

ValueError: could not convert string to float

Check now if the duration is an empty string and add basic test
coverage based on ddt for the subunit_trace command.

Change-Id: I9953019794ba53fcfcb20e32fecbe94da22c9565

os_testr/subunit_trace.py

@@ -220,7 +220,11 @@ def run_time():
     runtime = 0.0
     for k, v in RESULTS.items():
         for test in v:
-            runtime += float(get_duration(test['timestamps']).strip('s'))
+            test_dur = get_duration(test['timestamps']).strip('s')
+            # NOTE(toabctl): get_duration() can return an empty string
+            # which leads to a ValueError when casting to float
+            if test_dur:
+                runtime += float(test_dur)
     return runtime
 
 

os_testr/tests/test_subunit_trace.py

@@ -0,0 +1,61 @@
+# Copyright 2015 SUSE Linux GmbH
+# 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 datetime import datetime as dt
+
+from ddt import data
+from ddt import ddt
+from ddt import unpack
+from mock import patch
+
+from os_testr import subunit_trace
+from os_testr.tests import base
+
+
+@ddt
+class TestSubunitTrace(base.TestCase):
+
+    @data(([dt(2015, 4, 17, 22, 23, 14, 111111),
+            dt(2015, 4, 17, 22, 23, 14, 111111)],
+           "0.000000s"),
+          ([dt(2015, 4, 17, 22, 23, 14, 111111),
+            dt(2015, 4, 17, 22, 23, 15, 111111)],
+           "1.000000s"),
+          ([dt(2015, 4, 17, 22, 23, 14, 111111),
+            None],
+           ""))
+    @unpack
+    def test_get_durating(self, timestamps, expected_result):
+        self.assertEqual(subunit_trace.get_duration(timestamps),
+                         expected_result)
+
+    @data(([dt(2015, 4, 17, 22, 23, 14, 111111),
+            dt(2015, 4, 17, 22, 23, 14, 111111)],
+           0.0),
+          ([dt(2015, 4, 17, 22, 23, 14, 111111),
+            dt(2015, 4, 17, 22, 23, 15, 111111)],
+           1.0),
+          ([dt(2015, 4, 17, 22, 23, 14, 111111),
+            None],
+           0.0))
+    @unpack
+    def test_run_time(self, timestamps, expected_result):
+        patched_res = {
+            0: [
+                {'timestamps': timestamps}
+            ]
+        }
+        with patch.dict(subunit_trace.RESULTS, patched_res, clear=True):
+            self.assertEqual(subunit_trace.run_time(), expected_result)

test-requirements.txt

@@ -10,3 +10,4 @@ sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
 oslosphinx>=2.2.0  # Apache-2.0
 oslotest>=1.2.0  # Apache-2.0
 testscenarios>=0.4
+ddt>=0.4.0