fixup! calendar: fix calendar exception when calendar does not repeat

add missing descriptive docstrings for added test methods

product/ERP5/tests/testCalendar.py

@@ -1513,7 +1513,13 @@ class TestCalendar(ERP5ReportTestCase):
                         available_time_movement_list])
 
   def test_GroupCalendarPeriodExceptionWhenNoAvailability(self):
-    # #20171205-E91759 reproduction
+    """Having a group calendar exception on a day where the calendar does not
+    provide availability should index no availability for that day, without
+    error.
+
+    This is non-regression test for bug #20171205-E91759 , a problem in how
+    `asMovementList` build the list of movements for indexing.
+    """
     group_calendar = self.portal.group_calendar_module.newContent(
         portal_type='Group Calendar')
     group_calendar_period = group_calendar.newContent(
@@ -1562,7 +1568,13 @@ class TestCalendar(ERP5ReportTestCase):
             node_uid=person.getUid()))
 
   def test_GroupCalendarPeriodExceptionTwoExceptionsOnSameDay(self):
-    # #20171205-E91759 reproduction
+    """Having two group calendar exceptions on the same day should index no
+    availability for that day, without error.
+
+    This is another non-regression test for bug #20171205-E91759 , with the
+    second exception, we are in the same scenario of having an exception for a
+    day where there's no availability.
+    """
     group_calendar = self.portal.group_calendar_module.newContent(
         portal_type='Group Calendar')
     group_calendar_period = group_calendar.newContent(