fix: Added type hint for start and end datetime for interval

arrow/arrow.py

@@ -299,7 +299,9 @@ def utcfromtimestamp(cls, timestamp: Union[int, float, str]) -> "Arrow":
         )
 
     @classmethod
-    def fromdatetime(cls, dt: dt_datetime, tzinfo: Optional[TZ_EXPR] = None) -> "Arrow":
+    def fromdatetime(
+        cls, dt: Union["Arrow", dt_datetime], tzinfo: Optional[TZ_EXPR] = None
+    ) -> "Arrow":
         """Constructs an :class:`Arrow <arrow.arrow.Arrow>` object from a ``datetime`` and
         optional replacement timezone.
 
@@ -643,8 +645,8 @@ def ceil(self, frame: _T_FRAMES, **kwargs: Any) -> "Arrow":
     def span_range(
         cls,
         frame: _T_FRAMES,
-        start: dt_datetime,
-        end: dt_datetime,
+        start: Union["Arrow", dt_datetime],
+        end: Union["Arrow", dt_datetime],
         tz: Optional[TZ_EXPR] = None,
         limit: Optional[int] = None,
         bounds: _BOUNDS = "[)",
@@ -725,8 +727,8 @@ def span_range(
     def interval(
         cls,
         frame: _T_FRAMES,
-        start: dt_datetime,
-        end: dt_datetime,
+        start: Union["Arrow", dt_datetime],
+        end: Union["Arrow", dt_datetime],
         interval: int = 1,
         tz: Optional[TZ_EXPR] = None,
         bounds: _BOUNDS = "[)",
@@ -736,8 +738,8 @@ def interval(
         representing a series of intervals between two inputs.
 
         :param frame: The timeframe.  Can be any ``datetime`` property (day, hour, minute...).
-        :param start: A datetime expression, the start of the range.
-        :param end: (optional) A datetime expression, the end of the range.
+        :param start: A datetime or Arrow expression, the start of the range.
+        :param end: (optional) A datetime or Arrow expression, the end of the range.
         :param interval: (optional) Time interval for the given time frame.
         :param tz: (optional) A timezone expression.  Defaults to UTC.
         :param bounds: (optional) a ``str`` of either '()', '(]', '[)', or '[]' that specifies

tests/test_arrow.py

@@ -1587,6 +1587,48 @@ def test_correct(self):
             ),
         ]
 
+    def test_arrow_objects_input(self):
+        # start and end passed as Arrow instances instead of datetime
+        start = arrow.Arrow(2013, 5, 5, 12, 30)
+        end = arrow.Arrow(2013, 5, 5, 17, 15)
+        result = list(arrow.Arrow.interval("hour", start, end, 2))
+
+        assert result == [
+            (
+                arrow.Arrow(2013, 5, 5, 12),
+                arrow.Arrow(2013, 5, 5, 13, 59, 59, 999999),
+            ),
+            (
+                arrow.Arrow(2013, 5, 5, 14),
+                arrow.Arrow(2013, 5, 5, 15, 59, 59, 999999),
+            ),
+            (
+                arrow.Arrow(2013, 5, 5, 16),
+                arrow.Arrow(2013, 5, 5, 17, 59, 59, 999999),
+            ),
+        ]
+
+    def test_arrow_and_datetime_input(self):
+        # mixed types should also be accepted
+        start = arrow.Arrow(2013, 5, 5, 12, 30)
+        end = datetime(2013, 5, 5, 17, 15)
+        result = list(arrow.Arrow.interval("hour", start, end, 2))
+
+        assert result == [
+            (
+                arrow.Arrow(2013, 5, 5, 12),
+                arrow.Arrow(2013, 5, 5, 13, 59, 59, 999999),
+            ),
+            (
+                arrow.Arrow(2013, 5, 5, 14),
+                arrow.Arrow(2013, 5, 5, 15, 59, 59, 999999),
+            ),
+            (
+                arrow.Arrow(2013, 5, 5, 16),
+                arrow.Arrow(2013, 5, 5, 17, 59, 59, 999999),
+            ),
+        ]
+
     def test_bounds_param_is_passed(self):
         result = list(
             arrow.Arrow.interval(