While going forward/backward in time, cap dt.day to the last day of t…

…he new month.

Fixes #95.

metabot/util/humanize.py

@@ -1,5 +1,6 @@
 """Quick routines to convert machine-friendly data types to human-friendly strings."""
 
+import calendar
 import datetime
 import time as _time
 
@@ -46,18 +47,28 @@ def dayofmonth(dom):
 
 
 def _nextmonth(dt, months=1):
+    day = dt.day
+
     while months > 0:
         months -= 1
         if dt.month == 12:
-            dt = dt.replace(year=dt.year + 1, month=1)
+            year = dt.year + 1
+            month = 1
         else:
-            dt = dt.replace(month=dt.month + 1)
+            year = dt.year
+            month = dt.month + 1
+        _, ndays = calendar.monthrange(year, month)
+        dt = dt.replace(year=year, month=month, day=min(day, ndays))
     while months < 0:
         months += 1
         if dt.month == 1:
-            dt = dt.replace(year=dt.year - 1, month=12)
+            year = dt.year - 1
+            month = 12
         else:
-            dt = dt.replace(month=dt.month - 1)
+            year = dt.year
+            month = dt.month - 1
+        _, ndays = calendar.monthrange(year, month)
+        dt = dt.replace(year=year, month=month, day=min(day, ndays))
     return dt
 
 

metabot/util/test_humanize.py

@@ -26,6 +26,26 @@ def test_humanize_dayofmonth():
     assert humanize.dayofmonth(21) == '21ˢᵗ'
 
 
+def test_nextmonth():
+    """Quick tests for humanize._nextmonth."""
+
+    # pylint: disable=protected-access
+    assert humanize._nextmonth(datetime.date(2024, 11, 1)) == datetime.date(2024, 12, 1)
+    assert humanize._nextmonth(datetime.date(2024, 12, 1), -1) == datetime.date(2024, 11, 1)
+    assert humanize._nextmonth(datetime.date(2024, 12, 1)) == datetime.date(2025, 1, 1)
+    assert humanize._nextmonth(datetime.date(2025, 1, 1), -1) == datetime.date(2024, 12, 1)
+
+    assert humanize._nextmonth(datetime.date(2025, 1, 31), 1) == datetime.date(2025, 2, 28)
+    assert humanize._nextmonth(datetime.date(2025, 1, 31), 2) == datetime.date(2025, 3, 31)
+    assert humanize._nextmonth(datetime.date(2025, 1, 31), 3) == datetime.date(2025, 4, 30)
+    assert humanize._nextmonth(datetime.date(2025, 1, 31), 4) == datetime.date(2025, 5, 31)
+
+    assert humanize._nextmonth(datetime.date(2025, 5, 31), -1) == datetime.date(2025, 4, 30)
+    assert humanize._nextmonth(datetime.date(2025, 5, 31), -2) == datetime.date(2025, 3, 31)
+    assert humanize._nextmonth(datetime.date(2025, 5, 31), -3) == datetime.date(2025, 2, 28)
+    assert humanize._nextmonth(datetime.date(2025, 5, 31), -4) == datetime.date(2025, 1, 31)
+
+
 def test_humanize_howrecent():
     """Quick tests for humanize.howrecent."""
 

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = 'metabot'
-version = '0.3.20'
+version = '0.3.20.1'
 description = 'Modularized, multi-account bot.'
 readme = 'README.md'
 authors = [