From 24c4426e3ef915a388545357ba924738b15950ce Mon Sep 17 00:00:00 2001
From: Allen Porter <allen.porter@gmail.com>
Date: Sun, 5 Nov 2023 18:37:55 -0800
Subject: [PATCH] Add exception catching for pyparsing errors

---
 ical/calendar_stream.py       | 18 +++++++++++++-----
 tests/test_calendar.py        |  7 +++++++
 tests/test_calendar_stream.py |  8 ++++++++
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/ical/calendar_stream.py b/ical/calendar_stream.py
index 2327b39..4892ad5 100644
--- a/ical/calendar_stream.py
+++ b/ical/calendar_stream.py
@@ -29,16 +29,18 @@
 from __future__ import annotations
 
 import logging
+import pyparsing
 
 try:
-    from pydantic.v1 import Field
+    from pydantic.v1 import Field, ValidationError
 except ImportError:
-    from pydantic import Field
+    from pydantic import Field, ValidationError
 
 from .calendar import Calendar
 from .component import ComponentModel
 from .parsing.component import encode_content, parse_content
 from .types.data_types import DATA_TYPE
+from .exceptions import CalendarParseError
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -55,13 +57,19 @@ class CalendarStream(ComponentModel):
     @classmethod
     def from_ics(cls, content: str) -> "CalendarStream":
         """Factory method to create a new instance from an rfc5545 iCalendar content."""
-        components = parse_content(content)
+        try:
+            components = parse_content(content)
+        except pyparsing.ParseException as err:
+            raise CalendarParseError(f"Failed to parse calendar stream: {err}") from err
         result: dict[str, list] = {"vcalendar": []}
         for component in components:
             result.setdefault(component.name, [])
             result[component.name].append(component.as_dict())
         _LOGGER.debug("Parsing object %s", result)
-        return cls.parse_obj(result)
+        try:
+            return cls.parse_obj(result)
+        except ValidationError as err:
+            raise CalendarParseError(f"Failed to parse calendar stream: {err}") from err
 
     def ics(self) -> str:
         """Encode the calendar stream as an rfc5545 iCalendar Stream content."""
@@ -79,7 +87,7 @@ def calendar_from_ics(cls, content: str) -> Calendar:
             return stream.calendars[0]
         if len(stream.calendars) == 0:
             return Calendar()
-        raise ValueError("Calendar Stream had more than one calendar")
+        raise CalendarParseError("Calendar Stream had more than one calendar")
 
     @classmethod
     def calendar_to_ics(cls, calendar: Calendar) -> str:
diff --git a/tests/test_calendar.py b/tests/test_calendar.py
index ca58c49..9f9a4c1 100644
--- a/tests/test_calendar.py
+++ b/tests/test_calendar.py
@@ -13,6 +13,7 @@
 
 from ical.calendar import Calendar
 from ical.calendar_stream import IcsCalendarStream
+from ical.exceptions import CalendarParseError
 from ical.event import Event
 from ical.types.recur import Recur
 
@@ -458,3 +459,9 @@ def test_floating_time_with_timezone_propagation() -> None:
         it = iter(cal.timeline_tz(zoneinfo.ZoneInfo("Europe/Brussels")))
         for i in range(0, 30):
             next(it)
+
+
+def test_invalid_ics() -> None:
+    """Test a parse failure for ics content."""
+    with pytest.raises(CalendarParseError, match="Failed to parse calendar stream"):
+        IcsCalendarStream.calendar_from_ics("invalid")
diff --git a/tests/test_calendar_stream.py b/tests/test_calendar_stream.py
index e23ff3f..cd3887e 100644
--- a/tests/test_calendar_stream.py
+++ b/tests/test_calendar_stream.py
@@ -6,6 +6,7 @@
 import pytest
 from pytest_golden.plugin import GoldenTestFixture
 
+from ical.exceptions import CalendarParseError
 from ical.calendar_stream import CalendarStream, IcsCalendarStream
 
 
@@ -58,3 +59,10 @@ def test_serialize(golden: GoldenTestFixture) -> None:
     """Fixture to read golden file and compare to golden output."""
     cal = IcsCalendarStream.from_ics(golden["input"])
     assert cal.ics() == golden.get("encoded", golden["input"])
+
+
+
+def test_invalid_ics(mock_prodid: Generator[None, None, None]) -> None:
+    """Test parsing failures for ics content."""
+    with pytest.raises(CalendarParseError, match="Failed to parse calendar stream"):
+        IcsCalendarStream.calendar_from_ics("invalid")
\ No newline at end of file