Add ics_compare and use it in _testRespondTo()

This new class uses vobject.ics_diff() to compare 2 VCALENDAR components.
We should use this instead of textually comparing events for equality
in future tests.

Tests/Integration/test-davacl.py

@@ -681,9 +681,10 @@ class DAVCalendarAclTest(DAVAclTest):
                                               "organizer_line": "ORGANIZER:mailto:someone@nowhere.com\n",
                                               "attendee_line": att_line}
             event = self._getEvent(event_class, True)
-            self.assertEquals(exp_event.strip(), event.strip(),
-                              "'respond to' event does not match:\nreceived:\n"
-                              "/%s/\nexpected:\n/%s/" % (event, exp_event))
+            ics_diff = utilities.ics_compare(exp_event, event)
+            self.assertTrue(ics_diff.areEqual(),
+                            "'respond to' event does not match:\n"
+                            "Diff(expected, got):\n %s" % ics_diff.textDiff())
 
 class DAVAddressBookAclTest(DAVAclTest):
     resource = '/SOGo/dav/%s/Contacts/test-dav-acl/' % username

Tests/Integration/utilities.py

@@ -1,9 +1,60 @@
 #!/usr/bin/python
 
+import StringIO
+import sys
 import unittest
+import vobject
+import vobject.ics_diff
 import webdavlib
 import xml.sax.saxutils
 
+class ics_compare():
+
+    def __init__(self, event1, event2):
+      self.event1 = event1
+      self.event2 = event2
+      self.diffs = None
+
+    def _vcalendarComponent(self, event):
+      event_component = None
+      for item in vobject.readComponents(event):
+        if item.name == "VCALENDAR":
+          event_component = item
+      return event_component
+
+    def areEqual(self):
+        s_event1 = StringIO.StringIO(self.event1)
+        s_event2 = StringIO.StringIO(self.event2)
+
+        event1_vcalendar = self._vcalendarComponent(s_event1)
+        if event1_vcalendar is None:
+            raise Exception("No VCALENDAR component in event1")
+
+        event2_vcalendar = self._vcalendarComponent(s_event2)
+        if event2_vcalendar is None:
+            raise Exception("No VCALENDAR component in event2")
+
+        self.diffs = vobject.ics_diff.diff(event1_vcalendar, event2_vcalendar)
+        if not self.diffs:
+            return True
+        else:
+            return False
+
+    def textDiff(self):
+        saved_stdout = sys.stdout
+        out = StringIO.StringIO()
+        sys.stdout = out
+        try :
+            if self.diffs is not None:
+                for (left, right) in self.diffs:
+                    left.prettyPrint()
+                    right.prettyPrint()
+        finally:
+            sys.stdout = saved_stdout
+
+        return out.getvalue().strip()
+
+
 class TestUtility():
     def __init__(self, test, client, resource = None):
         self.test = test
@@ -144,3 +195,5 @@ class TestAddressBookACLUtility(TestACLUtility):
             sogoRights.append(sogoRightsTable[k])
 
         return sogoRights
+
+