Exclude core from being collected as a stray occurrence

Author: niccokunzmann

recurring_ical_events/adapters/component.py

@@ -146,6 +146,14 @@ def is_modification(self) -> bool:
         """Whether the adapter is a modification."""
         return bool(self.recurrence_ids)
 
+    def is_core(self):
+        """Whether this has generation rules present."""
+        return (
+            "RRULE" in self._component
+            or "RDATE" in self._component
+            or "EXDATE" in self._component
+        )
+
     @cached_property
     def sequence(self) -> int:
         """The sequence in the history of modification.

recurring_ical_events/series/rrule.py

@@ -322,7 +322,7 @@ def __init__(self, components: Sequence[ComponentAdapter]):
         self.recurrence_id_to_modification: dict[
             RecurrenceID, ComponentAdapter
         ] = {}  # RECURRENCE-ID -> adapter
-        self.this_and_future = []
+        self.this_and_future = []  # sorted, earliest first
         self._uid = components[0].uid
         core: ComponentAdapter | None = None
         for component in components:
@@ -351,7 +351,16 @@ def __init__(self, components: Sequence[ComponentAdapter]):
         self.compute_span_extension()
 
     def compute_span_extension(self):
-        """Compute how much to extend the span for the rrule to cover all events."""
+        """Compute how much to extend the span for the rrule to cover all events.
+
+        THISANDFUTURE can cause events to move.
+        This takes care of it by extending the query to make sure we capture such
+        occurrences.
+
+        This can be quite inefficient if events move a lot.
+        So, this algorithm should be sped up e.g. by remembering
+        how much these events moved.
+        """
         self._subtract_from_start, self._add_to_stop = (
             self.recurrence.extend_query_span_by
         )
@@ -453,11 +462,19 @@ def between(self, span_start: Time, span_stop: Time) -> Generator[Occurrence]:
             if occurrence.is_in_span(span_start, span_stop):
                 yield occurrence
         for modification in self.modifications:
-            # we assume that the modifications are actually included
+            # we assume that modifications are actually included
+            # even if they are not mentioned by the core.
+            # However, we exclude some:
+            # - if they were returned already
+            # - if an EXDATE excludes them
+            # - if they are a core
+            #   because they are expected to be included in the RRULE or RDATE
+            #   See https://github.com/niccokunzmann/python-recurring-ical-events/issues/253
             if (
                 modification in returned_modifications
                 or self.recurrence.check_exdates_datetime
                 & set(modification.recurrence_ids)
+                or modification.is_core()
             ):
                 continue
             if modification.is_in_span(span_start, span_stop):

recurring_ical_events/test/calendars/issue_253_additional_recurrence_id.ics

@@ -0,0 +1,30 @@
+BEGIN:VCALENDAR
+BEGIN:VEVENT
+DTSTAMP:20240707T214014Z
+DTSTART;VALUE=DATE:20240729
+DTEND;VALUE=DATE:20240804
+SUMMARY:test123
+CATEGORIES:other
+UID:111
+ORGANIZER:aaa
+RRULE:FREQ=WEEKLY;INTERVAL=2;BYDAY=MO
+RECURRENCE-ID;VALUE=DATE:20240729
+CREATED:20240311T051101Z
+LAST-MODIFIED:20240311T051101Z
+SEQUENCE:1
+END:VEVENT
+
+BEGIN:VEVENT
+DTSTAMP:20240707T214014Z
+DTSTART;VALUE=DATE:20240701
+DTEND;VALUE=DATE:20240708
+SUMMARY:test123
+CATEGORIES:other
+UID:111
+ORGANIZER:aaa
+RRULE:FREQ=WEEKLY;UNTIL=20240720;INTERVAL=2;BYDAY=MO
+CREATED:20240311T051101Z
+LAST-MODIFIED:20240701T063743Z
+SEQUENCE:2
+END:VEVENT
+END:VCALENDAR

recurring_ical_events/test/test_issue_253_additional_recurrence_id.py

@@ -0,0 +1,20 @@
+"""A new sequence should override an older one."""
+
+from datetime import date
+
+
+def test_recurrence_id_is_not_identical_to_dtstart(calendars):
+    """We have exactly two events in sequence 2.
+
+    start 2024-07-01 duration 7 days, 0:00:00
+    start 2024-07-15 duration 7 days, 0:00:00
+    """
+    events = list(calendars.issue_253_additional_recurrence_id.all())
+    for event in events:
+        start = event["DTSTART"].dt
+        duration = event["DTEND"].dt - event["DTSTART"].dt
+        print(f"start {start} duration {duration}")
+
+    assert len(events) == 2
+    assert events[0].start == date(2024, 7, 1)
+    assert events[1].start == date(2024, 7, 15)