assert_datetime_about_now*: Assert dt object is naive

Author: srittau

CHANGELOG.md

@@ -10,6 +10,8 @@ python-asserts adheres to [semantic versioning](https://semver.org/).
 
 ### Changed
 
+- Fail with `AssertionError`, not `TypeError`, if a timezone-aware datetime is
+  passed to `assert_datetime_about_now()` or `assert_datetime_about_now_utc()`.
 - Modernize type annotations.
 
 ### Removed

asserts/__init__.py

@@ -819,8 +819,10 @@ def assert_has_attr(obj, attribute, msg_fmt="{msg}"):
 _EPSILON_SECONDS = 5
 
 
-def assert_datetime_about_now(actual, msg_fmt="{msg}"):
-    """Fail if a datetime object is not within 5 seconds of the local time.
+def assert_datetime_about_now(
+    actual: datetime | None, msg_fmt: str = "{msg}"
+) -> None:
+    """Fail if a naive datetime object is not within 5 seconds of the local time.
 
     >>> assert_datetime_about_now(datetime.now())
     >>> assert_datetime_about_now(datetime(1900, 1, 1, 12, 0, 0))
@@ -835,18 +837,25 @@ def assert_datetime_about_now(actual, msg_fmt="{msg}"):
     """
 
     now = datetime.now()
+
     if actual is None:
         msg = "None is not a valid date/time"
         fail(msg_fmt.format(msg=msg, actual=actual, now=now))
+    if actual.tzinfo is not None:
+        msg = f"expected naive datetime object, got {actual!r}"
+        fail(msg_fmt.format(msg=msg, actual=actual, now=now))
+
     lower_bound = now - timedelta(seconds=_EPSILON_SECONDS)
     upper_bound = now + timedelta(seconds=_EPSILON_SECONDS)
     if not lower_bound <= actual <= upper_bound:
-        msg = "{!r} is not close to current date/time".format(actual)
+        msg = f"{actual!r} is not close to current date/time"
         fail(msg_fmt.format(msg=msg, actual=actual, now=now))
 
 
-def assert_datetime_about_now_utc(actual, msg_fmt="{msg}"):
-    """Fail if a datetime object is not within 5 seconds of UTC.
+def assert_datetime_about_now_utc(
+    actual: datetime | None, msg_fmt: str = "{msg}"
+) -> None:
+    """Fail if a naive datetime object is not within 5 seconds of UTC.
 
     >>> assert_datetime_about_now_utc(datetime.now(timezone.utc).replace(tzinfo=None))
     >>> assert_datetime_about_now_utc(datetime(1900, 1, 1, 12, 0, 0))
@@ -861,13 +870,18 @@ def assert_datetime_about_now_utc(actual, msg_fmt="{msg}"):
     """
 
     now = datetime.now(timezone.utc).replace(tzinfo=None)
+
     if actual is None:
         msg = "None is not a valid date/time"
         fail(msg_fmt.format(msg=msg, actual=actual, now=now))
+    if actual.tzinfo is not None:
+        msg = f"expected naive datetime object, got {actual!r}"
+        fail(msg_fmt.format(msg=msg, actual=actual, now=now))
+
     lower_bound = now - timedelta(seconds=_EPSILON_SECONDS)
     upper_bound = now + timedelta(seconds=_EPSILON_SECONDS)
     if not lower_bound <= actual <= upper_bound:
-        msg = "{!r} is not close to current UTC date/time".format(actual)
+        msg = f"{actual!r} is not close to current UTC date/time"
         fail(msg_fmt.format(msg=msg, actual=actual, now=now))
 
 
@@ -912,7 +926,9 @@ def __init__(self, exception: type[_E], msg_fmt: str = "{msg}") -> None:
         self.msg_fmt = msg_fmt
         self._exc_type = exception
         self._exc_val: _E | None = None
-        self._exception_name: str = getattr(exception, "__name__", str(exception))
+        self._exception_name: str = getattr(
+            exception, "__name__", str(exception)
+        )
         self._tests: list[Callable[[_E], object]] = []
 
     def __enter__(self) -> Self:

test_asserts.py

@@ -881,6 +881,11 @@ def test_assert_has_attr__does_not_have_attribute__custom_message(self):
 
     # assert_datetime_about_now()
 
+    def test_assert_datetime_about_now__aware_dt(self):
+        expected_message = "^expected naive datetime object, got "
+        with assert_raises_regex(AssertionError, expected_message):
+            assert_datetime_about_now(datetime.now(timezone.utc))
+
     def test_assert_datetime_about_now__close(self):
         assert_datetime_about_now(datetime.now())
 
@@ -930,6 +935,11 @@ def test_assert_datetime_about_now__custom_message(self):
 
     # assert_datetime_about_now_utc()
 
+    def test_assert_datetime_about_now_utc__aware_dt(self):
+        expected_message = "^expected naive datetime object, got "
+        with assert_raises_regex(AssertionError, expected_message):
+            assert_datetime_about_now_utc(datetime.now(timezone.utc))
+
     def test_assert_datetime_about_now_utc__close(self):
         assert_datetime_about_now_utc(
             datetime.now(timezone.utc).replace(tzinfo=None)