Reject gapped events

LICENSE

@@ -1,6 +1,6 @@
 drawcal
 
-Copyright (c) 2022-2025, Bnbnotify
+Copyright (c) 2022-2026, Bnbnotify
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

bin/drawcal

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

lib/drawcal/__init__.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -34,7 +34,7 @@
 """
 
 __prog__ = "drawcal"
-__version__ = "0.5.8"
+__version__ = "0.5.9"
 __author__ = "ryan@rsgalloway.com"
 
 

lib/drawcal/cli.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

lib/drawcal/config.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:

lib/drawcal/drawlib.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -38,6 +38,7 @@
 from PIL import Image, ImageFont, ImageDraw
 
 from drawcal import config
+from drawcal.events import validate_events
 
 # set some global date values
 _d = datetime.today()
@@ -115,6 +116,8 @@ def draw_calendar(
     # make sure events is a list
     if events is None:
         events = []
+    else:
+        validate_events(events)
 
     # categorize and track dates
     conflict_dates = set()

lib/drawcal/events.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2022-2025, Bnbnotify
+# Copyright (c) 2022-2026, Bnbnotify
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -43,6 +43,32 @@
 delta = timedelta(days=1)
 
 
+def validate_events(events):
+    """Validate drawcal event payloads."""
+
+    if not isinstance(events, list):
+        raise ValueError("events must be a list of event lists")
+
+    for event in events:
+        if not isinstance(event, list):
+            raise ValueError("each event must be a list of date strings")
+
+        parsed_days = []
+        for day in event:
+            if not isinstance(day, str):
+                raise ValueError("each event date must be a string in M/D/YYYY format")
+            try:
+                parsed_days.append(datetime.strptime(day, "%m/%d/%Y"))
+            except (TypeError, ValueError) as exc:
+                raise ValueError(f"invalid event date: {day}") from exc
+
+        for previous, current in zip(parsed_days, parsed_days[1:]):
+            if current <= previous:
+                raise ValueError("event dates must be in strictly increasing order")
+            if current - previous != delta:
+                raise ValueError("event dates must be consecutive with no gaps")
+
+
 def get_events(month=today.month, year=today.year):
     """Returns a list of randomly generated events."""
     from random import randint
@@ -86,18 +112,9 @@ def read_events(filepath):
     except json.JSONDecodeError as exc:
         raise ValueError(f"invalid JSON in events file: {filepath}") from exc
 
-    if not isinstance(events, list):
-        raise ValueError("events file must contain a list of event lists")
-
-    for event in events:
-        if not isinstance(event, list):
-            raise ValueError("each event must be a list of date strings")
-        for day in event:
-            if not isinstance(day, str):
-                raise ValueError("each event date must be a string in M/D/YYYY format")
-            try:
-                datetime.strptime(day, "%m/%d/%Y")
-            except (TypeError, ValueError) as exc:
-                raise ValueError(f"invalid event date: {day}") from exc
+    try:
+        validate_events(events)
+    except ValueError as exc:
+        raise ValueError(f"invalid events file: {exc}") from exc
 
     return events

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "drawcal"
-version = "0.5.8"
+version = "0.5.9"
 description = "Python library for drawing simple monthly calendar images with events."
 readme = "README.md"
 requires-python = ">=3.8"

tests/test_events.py

@@ -3,7 +3,7 @@
 import unittest
 from datetime import datetime
 
-from drawcal.events import get_events, read_events
+from drawcal.events import get_events, read_events, validate_events
 
 
 class ReadEventsTests(unittest.TestCase):
@@ -27,6 +27,16 @@ def test_read_events_rejects_invalid_dates(self):
             with self.assertRaises(ValueError):
                 read_events(path)
 
+    def test_read_events_rejects_gapped_events(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = f"{tmpdir}/events.json"
+
+            with open(path, "w", encoding="utf-8") as fp:
+                json.dump([["6/3/2022", "6/6/2022", "6/7/2022"]], fp)
+
+            with self.assertRaisesRegex(ValueError, "consecutive with no gaps"):
+                read_events(path)
+
 
 class GetEventsTests(unittest.TestCase):
     def test_get_events_stays_within_month(self):
@@ -38,3 +48,9 @@ def test_get_events_stays_within_month(self):
                 self.assertEqual(parsed.month, 2)
                 self.assertEqual(parsed.year, 2025)
                 self.assertLessEqual(parsed.day, 28)
+
+
+class ValidateEventsTests(unittest.TestCase):
+    def test_validate_events_rejects_gapped_direct_input(self):
+        with self.assertRaisesRegex(ValueError, "consecutive with no gaps"):
+            validate_events([["6/3/2022", "6/6/2022", "6/7/2022"]])

tests/test_render.py

@@ -34,3 +34,11 @@ def test_draw_calendar_matches_expected_image(self):
                 self.assertIsNone(
                     diff.getbbox(), "rendered image does not match fixture"
                 )
+
+    def test_draw_calendar_rejects_gapped_events(self):
+        with self.assertRaisesRegex(ValueError, "consecutive with no gaps"):
+            draw_calendar(
+                month=6,
+                year=2022,
+                events=[["6/3/2022", "6/6/2022", "6/7/2022"]],
+            )