From 94cc4eab00684738ce3aa9f7fb074fb14bf7cc90 Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Tue, 14 Apr 2026 04:01:45 +0530
Subject: [PATCH 1/8] fix: singleton param parsing

---
 tests/test_from_doctest.py |  2 +-
 vobjectx/base.py           | 43 +++++++++++++++++++-------------------
 vobjectx/vcard.py          |  8 +++----
 3 files changed, 25 insertions(+), 28 deletions(-)

diff --git a/tests/test_from_doctest.py b/tests/test_from_doctest.py
index 0cdaab5..8de76d3 100644
--- a/tests/test_from_doctest.py
+++ b/tests/test_from_doctest.py
@@ -127,4 +127,4 @@ def test_vcf_qp():
     )
     vcf = vo.read_one(vcf)
     assert vcf.n.value == Name(given="é")
-    assert vcf.serialize() == "BEGIN:VCARD\r\nVERSION:2.1\r\nFN:é\r\nN:;é;;;\r\nTEL:0111111111\r\nEND:VCARD\r\n"
+    assert vcf.serialize() == "BEGIN:VCARD\r\nVERSION:2.1\r\nFN:é\r\nN:;é;;;\r\nTEL;HOME:0111111111\r\nEND:VCARD\r\n"
diff --git a/vobjectx/base.py b/vobjectx/base.py
index 902c6b5..192e89e 100644
--- a/vobjectx/base.py
+++ b/vobjectx/base.py
@@ -187,15 +187,11 @@ class ContentLine(VBase):
     @ivar name:
         The uppercased name of the contentline.
     @ivar params:
-        A dictionary of parameters and associated lists of values (the list may
-        be empty for empty parameters).
+        A dictionary of parameters and associated lists of values.
+        Singleton params (e.g., WORK, CELL in vCard 2.1) are stored with an
+        empty list as the value.
     @ivar value:
         The value of the contentline.
-    @ivar singletonparams:
-        A list of parameters for which it's unclear if the string represents the
-        parameter name or the parameter value. In vCard 2.1, "The value string
-        can be specified alone in those cases where the value is unambiguous".
-        This is crazy, but we have to deal with it.
     @ivar encoded:
         A boolean describing whether the data in the content line is encoded.
         Generally, text read from a serialized vCard or vCalendar should be
@@ -218,16 +214,14 @@ def __init__(
         self.name = name.upper()
         self.encoded = encoded
         self.params = ContentDict()
-        self.singletonparams = []
         self.is_native = is_native
         self.line_number = line_number
         self.value: Any = value  # depends on Behavior
 
         def update_table(x):
-            if len(x) == 1:
-                self.singletonparams += x
-            else:
-                paramlist = self.params.setdefault(x[0].upper(), [])
+            # All params stored uniformly: singleton params get empty list
+            paramlist = self.params.setdefault(x[0], [])
+            if len(x) > 1:
                 paramlist.extend(x[1:])
 
         list(map(update_table, params))
@@ -238,9 +232,9 @@ def update_table(x):
             self.params["ENCODING"].remove("QUOTED-PRINTABLE")
             if not self.params["ENCODING"]:
                 del self.params["ENCODING"]
-        if "QUOTED-PRINTABLE" in self.singletonparams:
+        if "QUOTED-PRINTABLE" in self.params:
             qp = True
-            self.singletonparams.remove("QUOTED-PRINTABLE")
+            del self.params["QUOTED-PRINTABLE"]
         if qp:
             if "ENCODING" in self.params:
                 _encoding = self.params["ENCODING"]
@@ -269,7 +263,6 @@ def copy(self, copyit):
         self.params = copy.copy(copyit.params)
         for k, v in self.params.items():
             self.params[k] = copy.copy(v)
-        self.singletonparams = copy.copy(copyit.singletonparams)
         self.line_number = copyit.line_number
 
     def __eq__(self, other):
@@ -325,22 +318,25 @@ def __delattr__(self, name):
             raise AttributeError(name) from e
 
     def value_repr(self):
-        """
-        Transform the representation of the value
-        according to the behavior, if any.
-        """
+        """Transform the representation of the value according to the behavior, if any."""
         return self.behavior.value_repr(self) if self.behavior else self.value
 
+    @property
+    def display_params(self):
+        return {k: v for k, v in self.params.items() if v}
+
     def __repr__(self):
         try:
             value_repr = self.value_repr()
         except UnicodeEncodeError:
             value_repr = self.value_repr().encode("utf-8")
 
-        return f"<{self.name}{self.params}{value_repr}>"
+        # Filter out singleton params (empty lists) for display
+        return f"<{self.name}{self.display_params}{value_repr}>"
 
     def __unicode__(self):
-        return f"<{self.name}{self.params}{self.value_repr()}>"
+        # Filter out singleton params (empty lists) for display
+        return f"<{self.name}{self.display_params}{self.value_repr()}>"
 
     def pretty_print(self, level=0, tabwidth=3):
         pre = " " * level * tabwidth
@@ -364,7 +360,10 @@ def default_serialize(self, outbuf, line_length):
         for key in keys:
             paramstr = ",".join(dquote_escape(p) for p in self.params[key])
             try:
-                s.write(f";{key}={paramstr}")
+                if paramstr:
+                    s.write(f";{key}={paramstr}")
+                else:
+                    s.write(f";{key}")
             except (UnicodeDecodeError, UnicodeEncodeError):
                 s.write(f";{key}={paramstr.encode('utf-8')}")
         try:
diff --git a/vobjectx/vcard.py b/vobjectx/vcard.py
index 913ab3a..4399427 100644
--- a/vobjectx/vcard.py
+++ b/vobjectx/vcard.py
@@ -103,8 +103,8 @@ def decode(cls, line):
         ENCODING=b
         """
         if line.encoded:
-            if "BASE64" in line.singletonparams:
-                line.singletonparams.remove("BASE64")
+            if "BASE64" in line.params:
+                del line.params["BASE64"]
                 line.encoding_param = cls.base64string
             encoding = getattr(line, "encoding_param", None)
             if encoding:
@@ -115,9 +115,7 @@ def decode(cls, line):
 
     @classmethod
     def encode(cls, line):
-        """
-        Backslash escape line.value.
-        """
+        """Backslash escape line.value."""
         if not line.encoded:
             encoding = getattr(line, "encoding_param", None)
             if encoding and encoding.upper() == cls.base64string:

From 4459f6a4b6f369e25c767f1e89ff3a8d4f11dccb Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Tue, 14 Apr 2026 06:14:33 +0530
Subject: [PATCH 2/8] fix: add recurr-id validation

---
 .gitignore              |  2 ++
 tests/test_icalendar.py | 47 +++++++++++++++++++++++++++++++++++++++++
 vobjectx/icalendar.py   |  7 ++++++
 3 files changed, 56 insertions(+)

diff --git a/.gitignore b/.gitignore
index 9716195..03ee7a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,5 @@ venv/
 *coverage*
 
 new/
+AGENTS.md
+QWEN.md
diff --git a/tests/test_icalendar.py b/tests/test_icalendar.py
index b06d605..9e06db0 100644
--- a/tests/test_icalendar.py
+++ b/tests/test_icalendar.py
@@ -4,11 +4,13 @@
 from random import sample
 
 import dateutil
+import pytest
 from dateutil.rrule import MONTHLY, WEEKLY, rrule, rruleset
 
 from vobjectx import base
 from vobjectx.behavior import new_from_behavior
 from vobjectx.datatypes import Period
+from vobjectx.exceptions import ValidateError
 from vobjectx.icalendar import (
     RecurringComponent,
     TimezoneComponent,
@@ -265,3 +267,48 @@ def test_issue50():
     test_file = get_test_file("vobject_0050.ics")
     cal = base.read_one(test_file)
     assert dt.datetime(2024, 8, 12, 22, 30, tzinfo=UTC_TZ) == cal.vevent.dtend.value
+
+
+def test_vevent_dtstart_recurrence_id_type_mismatch():
+    """
+    Test that VEVENT validation fails when DTSTART and RECURRENCE-ID have different types.
+
+    DTSTART and RECURRENCE-ID must both be either datetime.date or datetime.datetime objects.
+    This test verifies the validation logic catches type mismatches.
+    """
+    # TODO: may simplify into simple test after redesign
+    # Create a VEVENT with DTSTART as datetime and RECURRENCE-ID as date (should fail)
+    vevent = new_from_behavior("VEVENT")
+    vevent.add("dtstart").value = dt.datetime(2024, 1, 15, 10, 0)
+    vevent.add("dtstamp").value = dt.datetime(2024, 1, 15, 10, 0)
+    vevent.add("recurrence_id").value = dt.date(2024, 1, 22)
+    vevent.add("uid").value = "dfvbdfvbdfljb"
+
+    # Validation should raise a ValidateError
+    with pytest.raises(ValidateError, match="RECURRENCE-ID and DTSTART must be of same type"):
+        vevent.validate(raise_exception=True)
+
+    # Create a VEVENT with DTSTART as date and RECURRENCE-ID as datetime (should fail)
+    vevent2 = new_from_behavior("VEVENT")
+    vevent2.add("dtstart").value = dt.date(2024, 1, 15)
+    vevent2.add("recurrence_id").value = dt.datetime(2024, 1, 22, 10, 0)
+
+    # Validation should raise a ValidateError
+    with pytest.raises(ValidateError, match="RECURRENCE-ID and DTSTART must be of same type"):
+        vevent2.validate()
+
+    # Create a VEVENT with both as datetime (should pass)
+    # vevent3 = new_from_behavior("VEVENT")
+    vevent.dtstart.value = dt.datetime(2024, 1, 15, 10, 0)
+    vevent.recurrence_id.value = dt.datetime(2024, 1, 22, 10, 0)
+
+    # Validation should pass
+    vevent.validate()
+
+    # Create a VEVENT with both as date (should pass)
+    vevent4 = new_from_behavior("VEVENT")
+    vevent4.add("dtstart").value = dt.date(2024, 1, 15)
+    vevent4.add("recurrence_id").value = dt.date(2024, 1, 22)
+
+    # Validation should pass
+    vevent4.validate()
diff --git a/vobjectx/icalendar.py b/vobjectx/icalendar.py
index bc262a5..b0780dc 100644
--- a/vobjectx/icalendar.py
+++ b/vobjectx/icalendar.py
@@ -581,6 +581,13 @@ def generate_implicit_parameters(obj):
             now = dt.datetime.now(UTC_TZ)
             obj.add("dtstamp").value = now
 
+    @classmethod
+    def validate(cls, obj, raise_exception=True, complain_unrecognized=False):
+        if hasattr(obj, "recurrence_id") and hasattr(obj, "dtstart"):
+            if type(obj.dtstart.value) is not type(obj.recurrence_id.value):
+                raise ValidateError("RECURRENCE-ID and DTSTART must be of same type")
+        return super().validate(obj, raise_exception, complain_unrecognized)
+
 
 class DateTimeBehavior(Behavior):
     """

From 20a2690bb7928cb818cc48c97ec6d718edffa272 Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Wed, 15 Apr 2026 02:00:53 +0530
Subject: [PATCH 3/8] refactor: get_transition

---
 tests/test_utils.py           |   3 +
 vobjectx/helper/parser.py     | 186 ++++++++++++----------------------
 vobjectx/helper/time_funcs.py |   8 ++
 vobjectx/ical/ical_helper.py  |   9 +-
 4 files changed, 81 insertions(+), 125 deletions(-)

diff --git a/tests/test_utils.py b/tests/test_utils.py
index 1c2a696..998e747 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,5 +1,6 @@
 import datetime as dt
 from io import StringIO
+from zoneinfo import ZoneInfo
 
 from dateutil.tz import tzutc
 
@@ -20,9 +21,11 @@ def test_date_to_string():
 
 
 def test_datetime_to_string():
+    tz_0_offset = ZoneInfo("Africa/Dakar")
     tc = {
         (dt.datetime(2000, 10, 29, 3, 0), False): "20001029T030000",
         (dt.datetime(2007, 3, 13, 12, 34, 32, tzinfo=tzutc()), True): "20070313T123432Z",
+        (dt.datetime(2000, 10, 29, 3, 0, tzinfo=tz_0_offset), False): "20001029T030000Z",
     }
     for inp, out in tc.items():
         assert datetime_to_string(*inp) == out
diff --git a/vobjectx/helper/parser.py b/vobjectx/helper/parser.py
index 497980a..cdfe575 100644
--- a/vobjectx/helper/parser.py
+++ b/vobjectx/helper/parser.py
@@ -1,143 +1,87 @@
 import datetime as dt
+from dataclasses import dataclass
 
-from vobjectx.exceptions import warn_if_true
+from dateutil.tz import gettz
 
 from .constants_tmp import TRANSITIONS
-from .imports_ import Callable, Iterator, contextlib
+from .imports_ import Callable, Iterator
+from .time_funcs import get_tzid
 
 CheckFunc = Callable[[dt.datetime], bool]
 DateIter = Iterator[dt.datetime]
 
+EPOCH = dt.datetime(1970, 1, 1, tzinfo=dt.timezone.utc)
+
+
+@dataclass
+class Transition:
+    transition_dt: dt.datetime
+    offset: int
+    is_standard: bool
+
+    def __eq__(self, other) -> bool:
+        return self.transition_dt == other.transition_dt and self.offset == other.offset
+
+
+def get_transistions(tzinfo: dt.tzinfo, start_year=1900, end_year=2030) -> list[Transition]:
+    new_year = dt.datetime(end_year, 1, 1)
+    _tzid = get_tzid(tzinfo)
+    if _tzid in ("UTC", None):
+        return [Transition(new_year, 0, True)]
+
+    _tz = gettz(_tzid)
+    if _tz is None:
+        return [Transition(new_year, 1, True)]
+    transistions = []
+
+    for ts, idx in zip(_tz._trans_list, _tz._trans_idx):  # pylint: disable=protected-access
+        transistion_date = EPOCH + dt.timedelta(seconds=ts)
+        if start_year <= transistion_date.year <= end_year:
+            # Use dstoffset to determine if this is standard time
+            # dstoffset=0 means standard time, dstoffset>0 means daylight time
+            is_standard = idx.dstoffset == dt.timedelta(0)
+            transistions.append(Transition(transistion_date, offset=idx.offset, is_standard=is_standard))
+
+    return transistions
+
 
 def get_transition(transition_to: str, year: int, tzinfo: dt.tzinfo) -> dt.datetime | None:
     """
     Return the datetime of the transition to/from DST, or None.
+
+    Returns the transition time as a naive datetime in local wall-clock time,
+    typically at 2:00 AM for most timezones.
     """
     assert transition_to in TRANSITIONS
 
-    def first_transition(iter_dates: DateIter, test_func: CheckFunc) -> dt.datetime | None:
-        """
-        Return the last date not matching test, or None if all tests matched.
-        """
-        success = None
-        for _dt in iter_dates:
-            if not test_func(_dt):
-                success = _dt
-            else:
-                if success is not None:
-                    return success
-        return success
-
-    def generate_dates(year_: int, month_: int = None, day_: int = None) -> DateIter:
-        """
-        Iterate over possible dates with unspecified values.
-        """
-        months = range(1, 13)
-        days = range(1, 32)
-        hours = range(24)
-        if month_ is None:
-            for _month in months:
-                yield dt.datetime(year_, _month, 1)
-        elif day_ is None:
-            for _day in days:
-                with contextlib.suppress(ValueError):
-                    yield dt.datetime(year_, month_, _day)
-        else:
-            for hour in hours:
-                yield dt.datetime(year_, month_, day_, hour)
-
-    def test(dt_: dt.datetime) -> bool:
-        is_standard_transition = transition_to == "standard"
-        is_daylight_transition = not is_standard_transition
-
-        # Detect Ambiguity (Overlap)
-        if tzinfo.dst(dt_.replace(fold=0)) != tzinfo.dst(dt_.replace(fold=1)):
-            return is_standard_transition
-
-        # Detect Gap (Non-existent)
-        dt_no_tz = dt_.replace(tzinfo=None)
-
-        offset = tzinfo.utcoffset(dt_.replace(fold=0))
-        if offset is not None:
-            dt_utc = (dt_no_tz - offset).replace(tzinfo=dt.timezone.utc)
-            dt_back = dt_utc.astimezone(tzinfo)
-            if dt_back.replace(tzinfo=None) != dt_no_tz:
-                return is_daylight_transition
-
-        is_dt_zerodelta = tzinfo.dst(dt_) == dt.timedelta(0)
-        return is_dt_zerodelta if is_standard_transition else not is_dt_zerodelta
-
-    month_dt = first_transition(generate_dates(year), test)
-    if month_dt is None:
-        return dt.datetime(year, 1, 1)  # new year
-    if month_dt.month == 12:
-        return None
-
-    # there was a good transition somewhere in a non-December month
-    month = month_dt.month
-    day = first_transition(generate_dates(year, month), test).day
-    uncorrected = first_transition(generate_dates(year, month, day), test)
-    warn_if_true(uncorrected is None)
-    if transition_to == "standard":
-        # assuming tzinfo.dst returns a new offset for the first possible hour, we need to add one hour for the
-        # offset change and another hour because first_transition returns the hour before the transition
-        return uncorrected + dt.timedelta(hours=2)
-
-    # Detect Gap (Non-existent) at uncorrected + 1 hour
-    # Note: first_transition for daylight returns the hour before it becomes daylight.
-    # In zoneinfo, this uncorrected+1 might already be 03:00 if 02:00 was skipped.
-    check_dt = uncorrected + dt.timedelta(hours=1)
-    is_gap = False
-
-    # Check if uncorrected + 1 hour is a non-existent time
-    # In zoneinfo, if check_dt was 02:00, and 02:00 is skipped,
-    # it might already show up as something else or we can check with fold.
-    # A better way to detect gap is to see if fold=0 and fold=1 result in same UTC but different wall clock
-    # OR just check if it was supposed to be uncorrected + 1 but the library moved it.
-
-    # If we are looking for daylight transition, we expect the offset to change.
-    tzinfo.utcoffset(check_dt.replace(fold=0))
-    tzinfo.utcoffset(check_dt.replace(fold=1))
-
-    # For a gap (Spring forward), fold=0 and fold=1 usually return the same (the 'after' offset)
-    # but we can detect it by checking if it's "imaginary"
-    dt_no_tz = check_dt.replace(tzinfo=None)
-    # Use an offset that we know existed just before
-    prev_offset = tzinfo.utcoffset((check_dt - dt.timedelta(hours=1)).replace(fold=0))
-    dt_utc_supposed = (dt_no_tz - prev_offset).replace(tzinfo=dt.timezone.utc)
-    dt_actual = dt_utc_supposed.astimezone(tzinfo)
-    if dt_actual.replace(tzinfo=None) != dt_no_tz:
-        is_gap = True
-
-    # For daylight (Spring forward), if it's a gap, pytz used to return the start of the gap.
-    # zoneinfo's get_transition logic (via fold) might find the end of the gap.
-    # If we found a gap, return the hour before the gap ends (which is the hour it starts).
-    if is_gap:
-        return check_dt - dt.timedelta(hours=1)
-
-    return check_dt
-
-
-def tzinfo_eq(tzinfo1: dt.tzinfo, tzinfo2: dt.tzinfo, start_year: int = 2000, end_year: int = 2020) -> bool:
-    """
-    Compare offsets and DST transitions from start_year to end_year.
-    """
+    # Get transitions for the specified year
+    transitions = get_transistions(tzinfo, start_year=year, end_year=year)
+
+    # Filter transitions based on the requested type
+    for trans in transitions:
+        is_standard = trans.is_standard
+        if (transition_to == "standard" and is_standard) or (transition_to == "daylight" and not is_standard):
+            # Use the UTC transition date directly, since transitions occur at
+            # a specific instant that corresponds to 2:00 AM local time
+            utc_dt = trans.transition_dt
+            return dt.datetime(utc_dt.year, utc_dt.month, utc_dt.day, 2, 0, 0)
+
+    # No transition found
+    return None
+
+
+def tzinfo_eq(tzinfo1: dt.tzinfo, tzinfo2: dt.tzinfo, start_year: int = 1950, end_year: int = 2030) -> bool:
+    """Compare offsets and DST transitions from start_year to end_year."""
     if tzinfo1 == tzinfo2:
         return True
     if tzinfo1 is None or tzinfo2 is None:
         return False
 
-    def dt_test(_dt):
-        if _dt is None:
-            return True
-        return tzinfo1.utcoffset(_dt) == tzinfo2.utcoffset(_dt)
+    t1_transitions = get_transistions(tzinfo1, start_year, end_year)
+    t2_transitions = get_transistions(tzinfo2, start_year, end_year)
+
+    for t1, t2 in zip(t1_transitions, t2_transitions):
+        if t1 != t2:
+            return False
 
-    if not dt_test(dt.datetime(start_year, 1, 1)):
-        return False
-    for year in range(start_year, end_year):
-        for transition_to in TRANSITIONS:
-            t1 = get_transition(transition_to, year, tzinfo1)
-            t2 = get_transition(transition_to, year, tzinfo2)
-            if t1 != t2 or not dt_test(t1):
-                return False
     return True
diff --git a/vobjectx/helper/time_funcs.py b/vobjectx/helper/time_funcs.py
index a04a7db..48f38fe 100644
--- a/vobjectx/helper/time_funcs.py
+++ b/vobjectx/helper/time_funcs.py
@@ -17,3 +17,11 @@ def split_delta(delta: dt.timedelta) -> SimpleDelta:
     hours, seconds = divmod(delta.seconds, 3600)
     minutes, seconds = divmod(seconds, 60)
     return SimpleDelta(days=delta.days, hours=hours, minutes=minutes, seconds=seconds)
+
+
+def get_tzid(tzinfo) -> str | None:
+    for attr in ("key", "_tzid", "zone", "tzid"):
+        tzid_ = getattr(tzinfo, attr, None)
+        if tzid_:
+            return tzid_
+    return None
diff --git a/vobjectx/ical/ical_helper.py b/vobjectx/ical/ical_helper.py
index 854c10b..a75f115 100644
--- a/vobjectx/ical/ical_helper.py
+++ b/vobjectx/ical/ical_helper.py
@@ -1,6 +1,8 @@
 import datetime as dt
 import math
 
+from dateutil.relativedelta import relativedelta
+
 from vobjectx import datatypes as vtypes
 from vobjectx.exceptions import ParseError
 from vobjectx.registry import TzidRegistry
@@ -15,10 +17,9 @@ def date_to_datetime_(dt_obj: dt.datetime | dt.date) -> dt.datetime:
 
 
 def from_last_week_(dt_: dt.datetime) -> int:
-    """
-    How many weeks from the end of the month dt is, starting from 1.
-    """
-    next_month = dt.datetime(dt_.year, dt_.month + 1, 1)
+    """How many weeks from the end of the month dt is, starting from 1."""
+
+    next_month = dt.datetime(dt_.year, dt_.month, 1) + relativedelta(months=1)
     time_diff = next_month - dt_
     days_gap = time_diff.days + bool(time_diff.seconds)
     return math.ceil(days_gap / 7)

From 10bf33ea1a3a1d9db39e006ac7bd0e5bb6b54783 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Fri, 1 May 2026 12:15:11 +0000
Subject: [PATCH 4/8] :arrow_up: Bump Mattraks/delete-workflow-runs from 2 to
 2.0.6

Bumps [Mattraks/delete-workflow-runs](https://github.com/mattraks/delete-workflow-runs) from 2 to 2.0.6.
- [Release notes](https://github.com/mattraks/delete-workflow-runs/releases)
- [Commits](https://github.com/mattraks/delete-workflow-runs/compare/v2...v2.0.6)

---
updated-dependencies:
- dependency-name: Mattraks/delete-workflow-runs
  dependency-version: 2.0.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
---
 .github/workflows/repo-cleaner.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/repo-cleaner.yml b/.github/workflows/repo-cleaner.yml
index fa4e8eb..91fe321 100644
--- a/.github/workflows/repo-cleaner.yml
+++ b/.github/workflows/repo-cleaner.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Delete old workflow runs
-        uses: Mattraks/delete-workflow-runs@v2
+        uses: Mattraks/delete-workflow-runs@v2.0.6
         with:
           retain_days: 15
           keep_minimum_runs: 5

From a3fa0f8d01ae97fc44f8c9c4eea15b97901847da Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Sat, 2 May 2026 03:16:02 +0530
Subject: [PATCH 5/8] fix: bad logic marked by AI

- set encoded as bool
- simplified and/or logic
- removed dead code
- handled line_validate method
- few type hinting
---
 vobjectx/base.py      | 47 +++++++++++++++++++++++++++----------------
 vobjectx/behavior.py  | 18 +++++------------
 vobjectx/icalendar.py | 40 ++++++++++++++++++------------------
 3 files changed, 55 insertions(+), 50 deletions(-)

diff --git a/vobjectx/base.py b/vobjectx/base.py
index 192e89e..baa79b8 100644
--- a/vobjectx/base.py
+++ b/vobjectx/base.py
@@ -6,7 +6,7 @@
 from .exceptions import NativeError, ParseError, VObjectError
 from .helper import Character as Char
 from .helper import byte_decoder, get_buffer, logger, split_by_size
-from .helper.imports_ import Any, TextIO, contextlib, copy, sys
+from .helper.imports_ import Any, Self, TextIO, contextlib, copy, sys
 from .patterns import patterns
 from .registry import BehaviorRegistry
 
@@ -39,7 +39,7 @@ def __init__(self, group=None, *args, **kwds):
         self.is_native = False
         self.encoded = False
 
-    def copy(self, copyit):
+    def copy(self, copyit: Self):
         self.group = copyit.group
         self.behavior = copyit.behavior
         self.parent_behavior = copyit.parent_behavior
@@ -202,7 +202,16 @@ class ContentLine(VBase):
 
     # pylint: disable=r0902,r0917
     def __init__(
-        self, name, params, value, group=None, encoded=False, is_native=False, line_number=None, *args, **kwds
+        self,
+        name: str,
+        params,
+        value,
+        group=None,
+        encoded: bool = False,
+        is_native: bool = False,
+        line_number: int = None,
+        *args,
+        **kwds,
     ):
         """
         Take output from parse_line, convert params list to dictionary.
@@ -255,11 +264,11 @@ def duplicate(cls, copyit):
         newcopy.copy(copyit)
         return newcopy
 
-    def copy(self, copyit):
+    def copy(self, copyit: Self):
         super().copy(copyit)
         self.name = copyit.name
         self.value = copy.copy(copyit.value)
-        self.encoded = self.encoded
+        self.encoded = copyit.encoded
         self.params = copy.copy(copyit.params)
         for k, v in self.params.items():
             self.params[k] = copy.copy(v)
@@ -374,6 +383,12 @@ def default_serialize(self, outbuf, line_length):
             self.behavior.decode(self)
         fold_one_line(outbuf, s.getvalue(), line_length)
 
+    # pylint: disable=w0613
+    @classmethod
+    def line_validate(cls, line, raise_exception=True, complain_unrecognized=False):
+        """Examine a line's parameters and values, return True if valid."""
+        return True
+
 
 class Component(VBase):
     """
@@ -407,7 +422,7 @@ def duplicate(cls, copyit):
         newcopy.copy(copyit)
         return newcopy
 
-    def copy(self, copyit):
+    def copy(self, copyit: Self):
         super().copy(copyit)
 
         # deep copy of contents
@@ -626,14 +641,13 @@ def parse_params(string):
     """
     _all = params_re.findall(string)
     all_parameters = []
-    for tup in _all:
-        param_list = [tup[0]]  # tup looks like (name, values_string)
-        for pair in param_values_re.findall(tup[1]):
+    for param in _all:
+        name, values_string = param
+        param_list = [name]
+        for pair in param_values_re.findall(values_string):
             # pair looks like ('', value) or (value, '')
-            if pair[0] != "":
-                param_list.append(pair[0])
-            else:
-                param_list.append(pair[1])
+            param_list.append(pair[0] or pair[1])
+
         all_parameters.append(param_list)
     return all_parameters
 
@@ -722,10 +736,9 @@ def text_line_to_content_line(text, n=None):
     return ContentLine(*parse_line(text, n), **{"encoded": True, "line_number": n})
 
 
-def dquote_escape(param) -> str:
-    """
-    Return param, or "param" if ',' or ';' or ':' is in param.
-    """
+def dquote_escape(param: str) -> str:
+    """Return param, or "param" if ',' or ';' or ':' is in param."""
+
     if '"' in param:
         raise VObjectError("Double quotes aren't allowed in parameter values.")
     for char in ",;:":  # sourcery skip # temp
diff --git a/vobjectx/behavior.py b/vobjectx/behavior.py
index 209c7c0..2128af2 100644
--- a/vobjectx/behavior.py
+++ b/vobjectx/behavior.py
@@ -78,8 +78,10 @@ def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
         """
         if not cls.allow_group and obj.group is not None:
             raise VObjectError(f"{obj} has a group, but this object doesn't support groups")
+
         if isinstance(obj, ContentLine):
-            return cls.line_validate(obj, raise_exception, complain_unrecognized)
+            return obj.line_validate(obj, raise_exception, complain_unrecognized)
+
         if isinstance(obj, Component):
             count = {}
             for child in obj.get_children():
@@ -101,23 +103,13 @@ def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
             return True
         raise VObjectError(f"{obj} is not a Component or Contentline")
 
-    @classmethod
-    def line_validate(cls, line, raise_exception, complain_unrecognized):
-        """Examine a line's parameters and values, return True if valid."""
-        # TODO: remove used param line, raise_exception, complain_unrecognized
-        if any([line, raise_exception, complain_unrecognized]):
-            pass
-        return True
-
     @classmethod
     def decode(cls, line):
-        if line.encoded:
-            line.encoded = 0
+        line.encoded = False
 
     @classmethod
     def encode(cls, line):
-        if not line.encoded:
-            line.encoded = 1
+        line.encoded = True
 
     @staticmethod
     def transform_to_native(obj):
diff --git a/vobjectx/icalendar.py b/vobjectx/icalendar.py
index b0780dc..1fdd143 100644
--- a/vobjectx/icalendar.py
+++ b/vobjectx/icalendar.py
@@ -9,7 +9,7 @@
 
 from . import datatypes as vtypes
 from .__about__ import __version__ as VERSION
-from .base import Component, ContentLine, fold_one_line
+from .base import Component, ContentLine, VBase, fold_one_line
 from .behavior import Behavior
 from .exceptions import AllException, NativeError, ParseError, ValidateError, VObjectError, warn_if_true
 from .helper import backslash_escape, get_buffer, get_random_int, logger
@@ -524,7 +524,7 @@ def decode(cls, line):
             line.encoded = False
 
     @classmethod
-    def encode(cls, line):
+    def encode(cls, line: VBase):
         """Backslash escape line.value."""
         if not line.encoded:
             encoding = getattr(line, "encoding_param", None)
@@ -610,7 +610,7 @@ def transform_to_native(obj):
         obj.is_native = True
         if obj.value == "":
             return obj
-        obj.value = obj.value
+
         # we're cheating a little here, parse_dtstart allows DATE
         obj.value = parse_dtstart(obj)
         if obj.value.tzinfo is None:
@@ -662,7 +662,7 @@ def transform_to_native(obj):
         obj.is_native = True
         if obj.value == "":
             return obj
-        obj.value = obj.value
+
         obj.value = parse_dtstart(obj, allow_signature_mismatch=True)
         if getattr(obj, "value_param", "DATE-TIME").upper() == "DATE-TIME" and hasattr(obj, "tzid_param"):
             # Keep a copy of the original TZID around
@@ -1005,11 +1005,11 @@ class VEvent(RecurringBehavior):
 
     @classmethod
     def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
-        if "dtend" not in obj.contents or "duration" not in obj.contents:
-            return super().validate(obj, raise_exception, complain_unrecognized)
-        if raise_exception:
-            raise ValidateError("VEVENT components cannot contain both DTEND and DURATION components")
-        return False
+        if "dtend" in obj.contents and "duration" in obj.contents:
+            if raise_exception:
+                raise ValidateError("VEVENT components cannot contain both DTEND and DURATION components")
+            return False
+        return super().validate(obj, raise_exception, complain_unrecognized)
 
 
 register_behavior(VEvent)
@@ -1060,11 +1060,11 @@ class VTodo(RecurringBehavior):
 
     @classmethod
     def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
-        if "due" not in obj.contents or "duration" not in obj.contents:
-            return super().validate(obj, raise_exception, complain_unrecognized)
-        if raise_exception:
-            raise ValidateError("VTODO components cannot contain both DUE and DURATION components")
-        return False
+        if "due" in obj.contents and "duration" in obj.contents:
+            if raise_exception:
+                raise ValidateError("VTODO components cannot contain both DUE and DURATION components")
+            return False
+        return super().validate(obj, raise_exception, complain_unrecognized)
 
 
 register_behavior(VTodo)
@@ -1210,11 +1210,11 @@ class VAvailability(VCalendarComponentBehavior):
 
     @classmethod
     def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
-        if "dtend" not in obj.contents or "duration" not in obj.contents:
-            return super().validate(obj, raise_exception, complain_unrecognized)
-        if raise_exception:
-            raise ValidateError("VAVAILABILITY components cannot contain both DTEND and DURATION components")
-        return False
+        if "dtend" in obj.contents and "duration" in obj.contents:
+            if raise_exception:
+                raise ValidateError("VAVAILABILITY components cannot contain both DTEND and DURATION components")
+            return False
+        return super().validate(obj, raise_exception, complain_unrecognized)
 
 
 register_behavior(VAvailability)
@@ -1272,7 +1272,7 @@ def transform_to_native(obj):
         if obj.is_native:
             return obj
         obj.is_native = True
-        obj.value = obj.value
+
         if obj.value == "":
             return obj
 

From aec9ad914bd5ce0c633d98f5d0b3294b82ae9d35 Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Sat, 2 May 2026 04:08:39 +0530
Subject: [PATCH 6/8] refact: confusing attribute/method name

- encoded to is_encoded
- copy method to return a copy.
---
 vobjectx/base.py      | 62 +++++++++++++++++++++----------------------
 vobjectx/behavior.py  |  4 +--
 vobjectx/icalendar.py | 16 +++++------
 vobjectx/vcard.py     | 10 +++----
 4 files changed, 45 insertions(+), 47 deletions(-)

diff --git a/vobjectx/base.py b/vobjectx/base.py
index baa79b8..b11daa0 100644
--- a/vobjectx/base.py
+++ b/vobjectx/base.py
@@ -37,9 +37,14 @@ def __init__(self, group=None, *args, **kwds):
         self.behavior = None
         self.parent_behavior = None
         self.is_native = False
-        self.encoded = False
+        self.is_encoded = False
 
-    def copy(self, copyit: Self):
+    def copy(self) -> Self:
+        newcopy = type(self)()
+        newcopy.upgrade_from(self)
+        return newcopy  # type: ignore
+
+    def upgrade_from(self, copyit: Self):
         self.group = copyit.group
         self.behavior = copyit.behavior
         self.parent_behavior = copyit.parent_behavior
@@ -79,11 +84,11 @@ def auto_behavior(self, cascade=False):
                 behavior = BehaviorRegistry.get(self.name, known_child_tup[2])
                 if behavior is not None:
                     self.set_behavior(behavior, cascade)
-                    if isinstance(self, ContentLine) and self.encoded:
+                    if isinstance(self, ContentLine) and self.is_encoded:
                         self.behavior.decode(self)
             elif isinstance(self, ContentLine):
                 self.behavior = parent_behavior.default_behavior
-                if self.encoded and self.behavior:
+                if self.is_encoded and self.behavior:
                     self.behavior.decode(self)
 
     def set_behavior(self, behavior, cascade=True):
@@ -107,7 +112,7 @@ def transform_to_native(self):
         if self.is_native or not self.behavior or not self.behavior.has_native:
             return self
 
-        self_orig = copy.copy(self)
+        self_orig = self.copy()
         try:
             return self.behavior.transform_to_native(self)
         except ParseError as e:
@@ -204,10 +209,10 @@ class ContentLine(VBase):
     def __init__(
         self,
         name: str,
-        params,
-        value,
+        params: list,
+        value: str,
         group=None,
-        encoded: bool = False,
+        is_encoded: bool = False,
         is_native: bool = False,
         line_number: int = None,
         *args,
@@ -221,7 +226,7 @@ def __init__(
         super().__init__(group, *args, **kwds)
 
         self.name = name.upper()
-        self.encoded = encoded
+        self.is_encoded = is_encoded
         self.params = ContentDict()
         self.is_native = is_native
         self.line_number = line_number
@@ -258,19 +263,18 @@ def update_table(x):
             except UnicodeDecodeError:
                 self.value = _value.decode("latin-1")
 
-    @classmethod
-    def duplicate(cls, copyit):
-        newcopy = cls("", {}, "")
-        newcopy.copy(copyit)
-        return newcopy
+    def copy(self) -> Self:
+        newcopy = ContentLine("", [], "")
+        newcopy.update_from(self)
+        return newcopy  # type: ignore
 
-    def copy(self, copyit: Self):
-        super().copy(copyit)
+    def update_from(self, copyit: Self):
+        super().upgrade_from(copyit)
         self.name = copyit.name
         self.value = copy.copy(copyit.value)
-        self.encoded = copyit.encoded
-        self.params = copy.copy(copyit.params)
-        for k, v in self.params.items():
+        self.is_encoded = copyit.is_encoded
+
+        for k, v in copyit.params.items():
             self.params[k] = copy.copy(v)
         self.line_number = copyit.line_number
 
@@ -352,11 +356,11 @@ def pretty_print(self, level=0, tabwidth=3):
         print(pre, f"{self.name}:", self.value_repr())
         if self.params:
             print(pre, "params for ", f"{self.name}:")
-            for k in self.params.keys():
-                print(pre + " " * tabwidth, k, self.params[k])
+            for k, v in self.params.items():
+                print(pre + " " * tabwidth, k, v)
 
     def default_serialize(self, outbuf, line_length):
-        started_encoded = self.encoded
+        started_encoded = self.is_encoded
         if self.behavior and not started_encoded:
             self.behavior.encode(self)
 
@@ -416,21 +420,15 @@ def __init__(self, name="", *args, **kwds):
         self.use_begin = bool(name)
         self.auto_behavior()
 
-    @classmethod
-    def duplicate(cls, copyit):
-        newcopy = cls()
-        newcopy.copy(copyit)
-        return newcopy
-
-    def copy(self, copyit: Self):
-        super().copy(copyit)
+    def upgrade_from(self, copyit: Self):
+        super().upgrade_from(copyit)
 
         # deep copy of contents
         self.contents = ContentDict()
         for key, lvalue in copyit.contents.items():
             newvalue = []
             for value in lvalue:
-                newitem = value.duplicate(value)
+                newitem = value.copy()
                 newvalue.append(newitem)
             self.contents[key] = newvalue
 
@@ -733,7 +731,7 @@ def get_logical_lines(fp, allow_qp=True):
 
 
 def text_line_to_content_line(text, n=None):
-    return ContentLine(*parse_line(text, n), **{"encoded": True, "line_number": n})
+    return ContentLine(*parse_line(text, n), **{"is_encoded": True, "line_number": n})
 
 
 def dquote_escape(param: str) -> str:
diff --git a/vobjectx/behavior.py b/vobjectx/behavior.py
index 2128af2..92cf4c8 100644
--- a/vobjectx/behavior.py
+++ b/vobjectx/behavior.py
@@ -105,11 +105,11 @@ def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
 
     @classmethod
     def decode(cls, line):
-        line.encoded = False
+        line.is_encoded = False
 
     @classmethod
     def encode(cls, line):
-        line.encoded = True
+        line.is_encoded = True
 
     @staticmethod
     def transform_to_native(obj):
diff --git a/vobjectx/icalendar.py b/vobjectx/icalendar.py
index 1fdd143..9eede69 100644
--- a/vobjectx/icalendar.py
+++ b/vobjectx/icalendar.py
@@ -515,24 +515,24 @@ class TextBehavior(Behavior):
     @classmethod
     def decode(cls, line):
         """Remove backslash escaping from line.value."""
-        if line.encoded:
+        if line.is_encoded:
             encoding = getattr(line, "encoding_param", None)
             if encoding and encoding.upper() == cls.base64string:
                 line.value = base64.b64decode(line.value)
             else:
                 line.value = string_to_text_values(line.value)[0]
-            line.encoded = False
+            line.is_encoded = False
 
     @classmethod
     def encode(cls, line: VBase):
         """Backslash escape line.value."""
-        if not line.encoded:
+        if not line.is_encoded:
             encoding = getattr(line, "encoding_param", None)
             if encoding and encoding.upper() == cls.base64string:
                 line.value = base64.b64encode(line.value.encode("utf-8")).decode("utf-8").replace("\n", "")
             else:
                 line.value = backslash_escape(line.value)
-            line.encoded = True
+            line.is_encoded = True
 
 
 class VCalendarComponentBehavior(Behavior):
@@ -751,18 +751,18 @@ def decode(cls, line):
         """
         Remove backslash escaping from line.value, then split on commas.
         """
-        if line.encoded:
+        if line.is_encoded:
             line.value = string_to_text_values(line.value, list_separator=cls.list_separator)
-            line.encoded = False
+            line.is_encoded = False
 
     @classmethod
     def encode(cls, line):
         """
         Backslash escape line.value.
         """
-        if not line.encoded:
+        if not line.is_encoded:
             line.value = cls.list_separator.join(backslash_escape(val) for val in line.value)
-            line.encoded = True
+            line.is_encoded = True
 
 
 class SemicolonMultiTextBehavior(MultiTextBehavior):
diff --git a/vobjectx/vcard.py b/vobjectx/vcard.py
index 4399427..3feef64 100644
--- a/vobjectx/vcard.py
+++ b/vobjectx/vcard.py
@@ -102,7 +102,7 @@ def decode(cls, line):
         vCard spec. If we encounter that, then we transform the parameter to
         ENCODING=b
         """
-        if line.encoded:
+        if line.is_encoded:
             if "BASE64" in line.params:
                 del line.params["BASE64"]
                 line.encoding_param = cls.base64string
@@ -111,13 +111,13 @@ def decode(cls, line):
                 line.value = byte_decoder(line.value)
             else:
                 line.value = string_to_text_values(line.value)[0]
-            line.encoded = False
+            line.is_encoded = False
 
     @classmethod
     def encode(cls, line):
         """Backslash escape line.value."""
-        if not line.encoded:
-            encoding = getattr(line, "encoding_param", None)
+        if not line.is_encoded:
+            encoding = getattr(line, "encoding_param", "")
             if encoding and encoding.upper() == cls.base64string:
                 if isinstance(line.value, bytes):
                     line.value = byte_encoder(line.value).decode("utf-8").replace("\n", "")
@@ -125,7 +125,7 @@ def encode(cls, line):
                     line.value = byte_encoder(line.value.encode(encoding)).decode("utf-8")
             else:
                 line.value = backslash_escape(line.value)
-            line.encoded = True
+            line.is_encoded = True
 
 
 class VCardBehavior(Behavior):

From 888033435bcc8a269be4c66f9db5eac287653eb1 Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Wed, 20 May 2026 06:12:40 +0530
Subject: [PATCH 7/8] refact : reduced memory need

---
 tests/test_calendar_serialization.py | 6 +++---
 tests/test_change_tz.py              | 2 +-
 tests/test_cli.py                    | 4 +---
 vobjectx/__init__.py                 | 2 +-
 vobjectx/helper/constants.py         | 2 +-
 vobjectx/helper/parser.py            | 2 +-
 vobjectx/helper/time_funcs.py        | 2 +-
 vobjectx/ics_diff.py                 | 2 +-
 8 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/tests/test_calendar_serialization.py b/tests/test_calendar_serialization.py
index b4e9455..6179712 100644
--- a/tests/test_calendar_serialization.py
+++ b/tests/test_calendar_serialization.py
@@ -8,6 +8,8 @@
 
 from .common import TEST_FILE_DIR, get_test_file
 
+tzs_from_file = dateutil.tz.tzical(f"{TEST_FILE_DIR}/timezones.ics").get("US/Pacific")
+
 
 def test_scratchbuild():
     """CreateCalendar 2.0 format from scratch"""
@@ -16,9 +18,7 @@ def test_scratchbuild():
     cal.add("vevent")
     cal.vevent.add("dtstart").value = dt.datetime(2006, 5, 9)
     cal.vevent.add("description").value = "Test event"
-    cal.vevent.add("created").value = dt.datetime(
-        2006, 1, 1, 10, tzinfo=dateutil.tz.tzical(f"{TEST_FILE_DIR}/timezones.ics").get("US/Pacific")
-    )
+    cal.vevent.add("created").value = dt.datetime(2006, 1, 1, 10, tzinfo=tzs_from_file)
     cal.vevent.add("uid").value = "Not very random UID"
     cal.vevent.add("dtstamp").value = dt.datetime(2017, 6, 26, 0, tzinfo=tzutc())
 
diff --git a/tests/test_change_tz.py b/tests/test_change_tz.py
index e4583e0..aa759e4 100644
--- a/tests/test_change_tz.py
+++ b/tests/test_change_tz.py
@@ -6,7 +6,7 @@
 from vobjectx.change_tz import change_tz
 
 
-@dataclass
+@dataclass(slots=True)
 class Node:
     value: str
 
diff --git a/tests/test_cli.py b/tests/test_cli.py
index df856d9..b74ab50 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1,9 +1,7 @@
 import subprocess
-from dataclasses import dataclass
 
 
-@dataclass
-class Cli:
+class Cli:  # pylint: disable=r0903
     ics_diff = "ics_diff"
     change_tz = "change_tz"
 
diff --git a/vobjectx/__init__.py b/vobjectx/__init__.py
index 8afa3ae..97a4cd7 100644
--- a/vobjectx/__init__.py
+++ b/vobjectx/__init__.py
@@ -95,4 +95,4 @@ def vCard():  # pylint:disable=invalid-name
     return new_from_behavior("vcard", "3.0")
 
 
-__all__ = ["icalendar", "vcard", "read_components", "read_one", "new_from_behavior", "iCalendar", "vCard"]
+__all__ = ["icalendar", "vcard", "read_components", "read_one", "new_from_behavior", "iCalendar", "vCard", "VERSION"]
diff --git a/vobjectx/helper/constants.py b/vobjectx/helper/constants.py
index 68f899d..d6b1c2d 100644
--- a/vobjectx/helper/constants.py
+++ b/vobjectx/helper/constants.py
@@ -1,7 +1,7 @@
 from dataclasses import dataclass
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class Character:
     """Space and Line-break characters"""
 
diff --git a/vobjectx/helper/parser.py b/vobjectx/helper/parser.py
index cdfe575..c6051b3 100644
--- a/vobjectx/helper/parser.py
+++ b/vobjectx/helper/parser.py
@@ -13,7 +13,7 @@
 EPOCH = dt.datetime(1970, 1, 1, tzinfo=dt.timezone.utc)
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class Transition:
     transition_dt: dt.datetime
     offset: int
diff --git a/vobjectx/helper/time_funcs.py b/vobjectx/helper/time_funcs.py
index 48f38fe..a1c4c9f 100644
--- a/vobjectx/helper/time_funcs.py
+++ b/vobjectx/helper/time_funcs.py
@@ -2,7 +2,7 @@
 from dataclasses import dataclass
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class SimpleDelta:
     days: int
     hours: int
diff --git a/vobjectx/ics_diff.py b/vobjectx/ics_diff.py
index 0c281ea..20c7884 100644
--- a/vobjectx/ics_diff.py
+++ b/vobjectx/ics_diff.py
@@ -41,7 +41,7 @@ def delete_extraneous(component, ignore_dtstamp=False):
         del component.dtstamp_list
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class ObjectWithSides:
     left: Component | ContentLine
     right: Component | ContentLine

From 13f15132acd72726dbac04ecb1af0d00a4e91074 Mon Sep 17 00:00:00 2001
From: rsb-23 <57601627+rsb-23@users.noreply.github.com>
Date: Wed, 20 May 2026 07:31:59 +0530
Subject: [PATCH 8/8] fix : added valarm validation

- supporting add_note
- improved logical lines
---
 vobjectx/base.py       | 55 +++++++++++++++++++++---------------------
 vobjectx/exceptions.py | 19 +++++++++++----
 vobjectx/icalendar.py  | 43 +++++++++++++++++++++------------
 3 files changed, 69 insertions(+), 48 deletions(-)

diff --git a/vobjectx/base.py b/vobjectx/base.py
index b11daa0..7d9700d 100644
--- a/vobjectx/base.py
+++ b/vobjectx/base.py
@@ -6,7 +6,7 @@
 from .exceptions import NativeError, ParseError, VObjectError
 from .helper import Character as Char
 from .helper import byte_decoder, get_buffer, logger, split_by_size
-from .helper.imports_ import Any, Self, TextIO, contextlib, copy, sys
+from .helper.imports_ import Any, Iterator, Self, TextIO, contextlib, copy, sys
 from .patterns import patterns
 from .registry import BehaviorRegistry
 
@@ -666,7 +666,7 @@ def parse_line(line, line_number=None):
     )
 
 
-def get_logical_lines(fp, allow_qp=True):
+def get_logical_lines(fp: TextIO, allow_qp: bool = True) -> Iterator:
     """
     Iterate through a stream, yielding one logical line at a time.
 
@@ -677,6 +677,10 @@ def get_logical_lines(fp, allow_qp=True):
 
     Quoted-printable data will be decoded in the Behavior decoding phase.
     """
+
+    def get_value(lines: list[str]):
+        return "".join(lines)
+
     if not allow_qp:
         val = fp.read(-1)
 
@@ -689,45 +693,40 @@ def get_logical_lines(fp, allow_qp=True):
         return
 
     quoted_printable = False
-    logical_line = get_buffer()
-    line_number = 0
+    logical_line: list[str] = []
     line_start_number = 0
-    while True:
-        line = fp.readline()
-        if line == "":
-            break
+
+    for n, line in enumerate(fp, start=1):
         line = line.rstrip(Char.CRLF)
-        line_number += 1
 
         if line.rstrip() == "":
-            if logical_line.tell() > 0:
-                yield logical_line.getvalue(), line_start_number
-            line_start_number = line_number
-            logical_line = get_buffer()
+            if logical_line:
+                yield get_value(logical_line), line_start_number
+            line_start_number = n
+            logical_line = []
             quoted_printable = False
             continue
 
         if quoted_printable and allow_qp:
-            logical_line.write("\n")
+            logical_line.append("\n")
             quoted_printable = False
         elif line[0] in Char.SPACEORTAB:
             line = line[1:]
-        elif logical_line.tell() > 0:
-            yield logical_line.getvalue(), line_start_number
-            line_start_number = line_number
-            logical_line = get_buffer()
+        elif logical_line:
+            yield get_value(logical_line), line_start_number
+            line_start_number = n
+            logical_line = []
         else:
-            logical_line = get_buffer()
-        logical_line.write(line)
+            logical_line = []
+        logical_line.append(line)
 
         # vCard 2.1 allows parameters to be encoded without a parameter name
         # False positives are unlikely, but possible.
-        val = logical_line.getvalue()
-        if val[-1] == "=" and val.lower().find("quoted-printable") >= 0:
+        if line[-1] == "=" and "quoted-printable" in get_value(logical_line).lower():
             quoted_printable = True
 
-    if logical_line.tell() > 0:
-        yield logical_line.getvalue(), line_start_number
+    if logical_line:
+        yield get_value(logical_line), line_start_number
 
 
 def text_line_to_content_line(text, n=None):
@@ -765,10 +764,10 @@ def default_serialize(obj, buf, line_length):
     return buf or outbuf.getvalue()
 
 
-def read_components(stream_or_string, validate=False, transform=True, ignore_unreadable=False, allow_qp=False):
-    """
-    Generate one Component at a time from a stream.
-    """
+def read_components(
+    stream_or_string, validate=False, transform=True, ignore_unreadable=False, allow_qp=False
+) -> Iterator[Component]:
+    """Generate one Component at a time from a stream."""
 
     def raise_parse_error(msg):
         raise ParseError(msg, n, inputs=stream_or_string)
diff --git a/vobjectx/exceptions.py b/vobjectx/exceptions.py
index c040809..9c87f9a 100644
--- a/vobjectx/exceptions.py
+++ b/vobjectx/exceptions.py
@@ -3,13 +3,21 @@
 
 class VObjectError(Exception):
     def __init__(self, msg, line_number=None):
-        self.msg = msg
+        super().__init__(msg)
         self.line_number = line_number
+        self.__notes__ = []
+
+    def add_note(self, note):
+        # TODO: remove this for 3.10 deprecation
+        self.__notes__.append(note)
 
     def __str__(self):
-        if self.line_number is None:
-            return repr(self.msg)
-        return f"At line {self.line_number!s}: {self.msg!s}"
+        msg = self.args[0]
+        if self.line_number is not None:
+            msg = f"At line {self.line_number}: {msg}"
+        if self.__notes__:
+            msg += "\n" + "\n".join(self.__notes__)
+        return msg
 
 
 class ParseError(VObjectError):
@@ -32,7 +40,8 @@ class AllException(VObjectError):
 
 class UnusedBranchError(VObjectError):
     def __init__(self):
-        super().__init__("Unexpected Execution : Report a bug", None)
+        super().__init__("Unused Branch Error", None)
+        super().add_note("Unexpected Execution : Report a bug")
 
 
 def warn_if_true(cond: bool = True, raise_error: bool = True):
diff --git a/vobjectx/icalendar.py b/vobjectx/icalendar.py
index 9eede69..e65e18a 100644
--- a/vobjectx/icalendar.py
+++ b/vobjectx/icalendar.py
@@ -1137,9 +1137,7 @@ class VFreeBusy(VCalendarComponentBehavior):
 
 
 class VAlarm(VCalendarComponentBehavior):
-    """
-    Alarm behavior.
-    """
+    """Alarm behavior"""
 
     name = "VALARM"
     description = "Alarms describe when and how to provide alerts about events and to-dos."
@@ -1153,9 +1151,7 @@ class VAlarm(VCalendarComponentBehavior):
 
     @staticmethod
     def generate_implicit_parameters(obj):
-        """
-        Create default ACTION and TRIGGER if they're not set.
-        """
+        """Create default ACTION and TRIGGER if they're not set."""
         if not hasattr(obj, "action"):
             obj.add("action").value = "AUDIO"
 
@@ -1163,17 +1159,34 @@ def generate_implicit_parameters(obj):
             obj.add("trigger").value = dt.timedelta(0)
 
     @classmethod
-    def validate(cls, obj, raise_exception=False, complain_unrecognized=False):
-        """
-        # TODO
-        if obj.contents.has_key('dtend') and obj.contents.has_key('duration'):
+    def validate(cls, obj, raise_exception: bool = True, complain_unrecognized: bool = False) -> bool:
+        contents = obj.contents
+
+        def fail(msg):
             if raise_exception:
-                raise ValidateError("VEVENT components cannot contain both DTEND and DURATION components")
+                raise ValidateError(msg)
             return False
-        else:
-            return super().validate(obj, raise_exception, *args)
-        """
-        return True
+
+        action = contents.action[0].value
+
+        # REPEAT and DURATION must appear together
+        if ("duration" in contents) ^ ("repeat" in contents):
+            return fail("VALARM DURATION and REPEAT must both be present/absent.")
+
+        if action == "DISPLAY":
+            if "description" not in contents:
+                return fail("DISPLAY VALARM missing DESCRIPTION")
+
+        elif action == "EMAIL":
+            for prop in ("description", "summary", "attendee"):
+                if prop not in contents:
+                    return fail(f"EMAIL VALARM missing {prop.upper()}")
+
+        elif action == "AUDIO":
+            if len(contents.get("attach", [])) > 1:
+                return fail("AUDIO VALARM can contain only one ATTACH")
+
+        return super().validate(obj, raise_exception, complain_unrecognized)
 
 
 register_behavior(VAlarm)