bug: crash when an event has mixed date and datetime

[fabien-michel]

Describe the bug

I've found the following event in the wild and it make the library crash on it becasue DTSTART is a date and DTEND is a datetime.
Possibly it is a invalid event, but it exists and the library is crashing even with skip_bad_series=True

ICS file

BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTART;VALUE=DATE:20230724
CREATED:20230606T153716Z
STATUS:CONFIRMED
SUMMARY:Congés
TRANSP:TRANSPARENT
DTSTAMP:20230704T085547Z
DTEND:20230817T000000Z
SEQUENCE:1
LAST-MODIFIED:20230731T161724Z
UID:19970901T130000Z[email protected]
END:VEVENT
END:VCALENDAR

Expected behavior

Event processed or event skipped (if skip_bad_series)
Tried to import the ics to Gnome Evolution and it take it without problem.

Console output

Traceback (most recent call last):
  File "xxx.py", line 49, in yyy
    ...
                     ^^^^^^^^^^^^^^^^^^^^^^^^
  File "xxx.py", line 104, in yyy
    zzz = recurring_ical_events.of(calendar, skip_bad_series=True).between(start_date, end_date)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 1446, in of
    return calendar_query(
           ^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 1290, in __init__
    component_adapter.collect_series_from(calendar, self._skip_errors)
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 1191, in collect_series_from
    result.append(self._series(components))
                  ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 610, in __init__
    self.compute_span_extension()
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 615, in compute_span_extension
    self.recurrence.extend_query_span_by
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 413, in extend_query_span_by
    return self.core.extend_query_span_by
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 259, in cached_property
    self.__dict__[name] = value = func(self)
                                  ^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 884, in extend_query_span_by
    subtract_from_start = self.duration
                          ^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 259, in cached_property
    self.__dict__[name] = value = func(self)
                                  ^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/recurring_ical_events.py", line 865, in duration
    return self.end - self.start
           ~~~~~~~~~^~~~~~~~~~~~
TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'datetime.date'

Version:

pip list

Additional context

Suggested implementation

    @cached_property
    def duration(self) -> datetime.timedelta:
        """The duration of the component."""
        start, end = make_comparable((self.start, self.end))
        return end - start

• add an ICS file, example:
  

  python-recurring-ical-events/test/calendars/issue-15-duplicated-events.ics

  Line 1 in f4a90b2

  BEGIN:VCALENDAR

• add a test, example:
  

  python-recurring-ical-events/test/test_issue_15.py

  Line 21 in f4a90b2

  def test_sequence_is_not_present(calendars):

• fix the bug and ensure the test code passes

---

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[fabien-michel]

.duration is called without making use of make_comparable in extend_query_span_by and in between. It fail at both locations.
The change propose to call make_comparable inside .duration but I'm not sure it is a nice fix.

[niccokunzmann]

Thanks for reporting!

I think, that might be a good place to fix it... I also think, the event is not standard compatible, so thanks for catching this!

We have to consider two cases here:

1. start is date, end is datetime -> make start a datetime
2. end is date, start is datetime -> make end a datetime

There is another edge case like this which will not error:

DTSTART is date, duration is timedelta with seconds

>>> datetime.date(2024, 10, 10) + datetime.timedelta(hours=26)
datetime.date(2024, 10, 11)

Tests for this issue:

• DTSTART is date, DTEND is datetime
  • Event
  • Todo
• DTSTART is datetime, DTEND is date
  • Event
  • Todo
• DTSTART is date, DURATION is timedelta with hours
  • Event
  • Todo

With these tests, the issue is solved for other cases like this in the wild. My guess is that the .end property should be adapted, not .duration.

I am looking at it from a place of perfection, I guess...

What are your thoughts on this? Would you like to work on it?