Take DST into account when converting to UTC

The UTC conversion was not taking DST into account. Now, it will be
properly calculated. Added more tests to cover.

Change-Id: I991dcf1fa6fddad28a1ab9e341c55d4396e4496f
Closes-Bug: #1675388

mistralclient/commands/v2/cron_triggers.py

@@ -159,9 +159,12 @@ class Create(command.ShowOne):
         if the_time:
             the_time = datetime.datetime.strptime(
                 the_time, datetime_format)
-            the_second = time.mktime(the_time.timetuple())
-            the_utc_time = datetime.datetime.utcfromtimestamp(the_second)
-            the_time = the_utc_time.strftime(datetime_format)
+
+            is_dst = time.daylight and time.localtime().tm_isdst > 0
+            utc_offset = - (time.altzone if is_dst else time.timezone)
+
+            the_time = (the_time - datetime.timedelta(
+                0, utc_offset)).strftime(datetime_format)
 
         return the_time
 

mistralclient/tests/unit/v2/test_cli_cron_triggers.py

@@ -14,9 +14,7 @@
 #    under the License.
 #
 
-import datetime
 import mock
-import time
 
 from mistralclient.api.v2 import cron_triggers
 from mistralclient.commands.v2 import cron_triggers as cron_triggers_cmd
@@ -88,17 +86,54 @@ class TestCLITriggersV2(base.BaseCommandTest):
             result[1]
         )
 
-    def test_convert_time_string_to_utc(self):
+    @mock.patch('mistralclient.commands.v2.cron_triggers.time')
+    def test_convert_time_string_to_utc_from_utc(self, mock_time):
         cmd = cron_triggers_cmd.Create(self.app, None)
 
+        mock_time.daylight = 0
+        mock_time.altzone = 0
+        mock_time.timezone = 0
+        mock_localtime = mock.Mock()
+        mock_localtime.tm_isdst = 0
+        mock_time.localtime.return_value = mock_localtime
+
         utc_value = cmd._convert_time_string_to_utc('4242-12-20 13:37')
 
-        is_dst = time.daylight and time.localtime().tm_isdst > 0
-        utc_offset = - (time.altzone if is_dst else time.timezone)
+        expected_time = '4242-12-20 13:37'
 
-        expected_time = (datetime.datetime(
-            4242, 12, 20, 13, 37) - datetime.timedelta(
-            0, utc_offset)).strftime('%Y-%m-%d %H:%M')
+        self.assertEqual(expected_time, utc_value)
+
+    @mock.patch('mistralclient.commands.v2.cron_triggers.time')
+    def test_convert_time_string_to_utc_from_dst(self, mock_time):
+        cmd = cron_triggers_cmd.Create(self.app, None)
+
+        mock_time.daylight = 1
+        mock_time.altzone = (4 * 60 * 60)
+        mock_time.timezone = (5 * 60 * 60)
+        mock_localtime = mock.Mock()
+        mock_localtime.tm_isdst = 1
+        mock_time.localtime.return_value = mock_localtime
+
+        utc_value = cmd._convert_time_string_to_utc('4242-12-20 13:37')
+
+        expected_time = '4242-12-20 17:37'
+
+        self.assertEqual(expected_time, utc_value)
+
+    @mock.patch('mistralclient.commands.v2.cron_triggers.time')
+    def test_convert_time_string_to_utc_no_dst(self, mock_time):
+        cmd = cron_triggers_cmd.Create(self.app, None)
+
+        mock_time.daylight = 1
+        mock_time.altzone = (4 * 60 * 60)
+        mock_time.timezone = (5 * 60 * 60)
+        mock_localtime = mock.Mock()
+        mock_localtime.tm_isdst = 0
+        mock_time.localtime.return_value = mock_localtime
+
+        utc_value = cmd._convert_time_string_to_utc('4242-12-20 13:37')
+
+        expected_time = '4242-12-20 18:37'
 
         self.assertEqual(expected_time, utc_value)