Reject bool in datetime/date/duration integer fields

src/pendulum/date.py

@@ -750,6 +750,13 @@ def replace(
         month: SupportsIndex | None = None,
         day: SupportsIndex | None = None,
     ) -> Self:
+        # bool is a subclass of int; reject so year=True does not become year 1
+        for name, value in (("year", year), ("month", month), ("day", day)):
+            if isinstance(value, bool):
+                raise TypeError(
+                    f"{name} must be an integer, not bool (got {value!r})."
+                )
+
         year = year if year is not None else self.year
         month = month if month is not None else self.month
         day = day if day is not None else self.day

src/pendulum/datetime.py

@@ -208,6 +208,21 @@ def set(
         microsecond: int | None = None,
         tz: str | float | Timezone | FixedTimezone | datetime.tzinfo | None = None,
     ) -> Self:
+        # bool is a subclass of int; reject so year=True does not become year 1
+        for name, value in (
+            ("year", year),
+            ("month", month),
+            ("day", day),
+            ("hour", hour),
+            ("minute", minute),
+            ("second", second),
+            ("microsecond", microsecond),
+        ):
+            if isinstance(value, bool):
+                raise TypeError(
+                    f"{name} must be an integer, not bool (got {value!r})."
+                )
+
         if year is None:
             year = self.year
         if month is None:
@@ -1299,6 +1314,23 @@ def replace(
         tzinfo: bool | datetime.tzinfo | Literal[True] | None = True,
         fold: int | None = None,
     ) -> Self:
+        # bool is a subclass of int; reject so year=True does not become year 1
+        # (tzinfo=True remains the sentinel for "keep current timezone")
+        for name, value in (
+            ("year", year),
+            ("month", month),
+            ("day", day),
+            ("hour", hour),
+            ("minute", minute),
+            ("second", second),
+            ("microsecond", microsecond),
+            ("fold", fold),
+        ):
+            if isinstance(value, bool):
+                raise TypeError(
+                    f"{name} must be an integer, not bool (got {value!r})."
+                )
+
         if year is None:
             year = self.year
         if month is None:

src/pendulum/duration.py

@@ -80,6 +80,23 @@ def __new__(
         years: float = 0,
         months: float = 0,
     ) -> Self:
+        # bool is a subclass of int; reject so years=True does not become 1 year
+        for name, value in (
+            ("days", days),
+            ("seconds", seconds),
+            ("microseconds", microseconds),
+            ("milliseconds", milliseconds),
+            ("minutes", minutes),
+            ("hours", hours),
+            ("weeks", weeks),
+            ("years", years),
+            ("months", months),
+        ):
+            if isinstance(value, bool):
+                raise TypeError(
+                    f"{name} must be a number, not bool (got {value!r})."
+                )
+
         if not isinstance(years, int) or not isinstance(months, int):
             raise ValueError("Float year and months are not supported")
 

src/pendulum/helpers.py

@@ -94,6 +94,22 @@ def add_duration(
     """
     Adds a duration to a date/datetime instance.
     """
+    # bool is a subclass of int; reject so days=True does not add 1 day
+    for name, value in (
+        ("years", years),
+        ("months", months),
+        ("weeks", weeks),
+        ("days", days),
+        ("hours", hours),
+        ("minutes", minutes),
+        ("seconds", seconds),
+        ("microseconds", microseconds),
+    ):
+        if isinstance(value, bool):
+            raise TypeError(
+                f"{name} must be an integer, not bool (got {value!r})."
+            )
+
     days += weeks * 7
 
     if (

tests/date/test_add.py

@@ -86,3 +86,12 @@ def test_addition_invalid_type():
 
     with pytest.raises(TypeError):
         3 + d
+
+
+def test_add_rejects_bool():
+    import pytest
+
+    d = pendulum.date(2020, 5, 15)
+    for key in ("years", "months", "weeks", "days"):
+        with pytest.raises(TypeError, match=key):
+            d.add(**{key: True})

tests/date/test_fluent_setters.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 import pendulum
 
 from tests.conftest import assert_date
@@ -27,3 +29,12 @@ def test_fluid_day_setter():
 
     assert new.day == 9
     assert d.day == 2
+
+
+def test_replace_rejects_bool():
+    d = pendulum.date(2020, 5, 15)
+    for key in ("year", "month", "day"):
+        with pytest.raises(TypeError, match=key):
+            d.replace(**{key: True})
+        with pytest.raises(TypeError, match=key):
+            d.replace(**{key: False})

tests/datetime/test_add.py

@@ -278,3 +278,12 @@ def test_interval_over_midnight_tz():
     new_end = start + interval
 
     assert new_end == end
+
+
+def test_add_rejects_bool():
+    dt = pendulum.datetime(2020, 5, 15, 12, 30, 45)
+    for key in ("years", "months", "weeks", "days", "hours", "minutes", "seconds", "microseconds"):
+        with pytest.raises(TypeError, match=key):
+            dt.add(**{key: True})
+        with pytest.raises(TypeError, match=key):
+            dt.add(**{key: False})

tests/datetime/test_fluent_setters.py

@@ -179,3 +179,14 @@ def test_replace_tzinfo_dst_transitioning_off():
     assert new.is_dst()
     assert new.offset == 7200
     assert new.timezone_name == "Europe/Paris"
+
+
+def test_set_rejects_bool():
+    import pytest
+
+    dt = pendulum.datetime(2020, 5, 15, 12, 30, 45)
+    for key in ("year", "month", "day", "hour", "minute", "second", "microsecond"):
+        with pytest.raises(TypeError, match=key):
+            dt.set(**{key: True})
+        with pytest.raises(TypeError, match=key):
+            dt.set(**{key: False})

tests/datetime/test_replace.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 import pendulum
 
 from tests.conftest import assert_datetime
@@ -59,3 +61,19 @@ def test_replace_tzinfo_dst_transitioning_off():
     assert not in_paris.is_dst()
     assert in_paris.offset == 3600
     assert in_paris.timezone_name == "Europe/Paris"
+
+
+def test_replace_rejects_bool():
+    dt = pendulum.datetime(2020, 5, 15, 12, 30, 45)
+    for key in ("year", "month", "day", "hour", "minute", "second", "microsecond", "fold"):
+        with pytest.raises(TypeError, match=key):
+            dt.replace(**{key: True})
+        with pytest.raises(TypeError, match=key):
+            dt.replace(**{key: False})
+
+
+def test_replace_tzinfo_true_still_allowed():
+    # tzinfo=True is the documented sentinel for keeping the current timezone
+    dt = pendulum.datetime(2020, 5, 15, 12, 30, 45, tz="UTC")
+    replaced = dt.replace(tzinfo=True)
+    assert replaced.timezone_name == dt.timezone_name

tests/duration/test_construct.py

@@ -97,3 +97,21 @@ def test_float_years_and_months():
 
     with pytest.raises(ValueError):
         pendulum.duration(months=1.5)
+
+
+def test_duration_rejects_bool():
+    for key in (
+        "days",
+        "seconds",
+        "microseconds",
+        "milliseconds",
+        "minutes",
+        "hours",
+        "weeks",
+        "years",
+        "months",
+    ):
+        with pytest.raises(TypeError, match=key):
+            pendulum.duration(**{key: True})
+        with pytest.raises(TypeError, match=key):
+            pendulum.duration(**{key: False})