Update signature and tests

pandas/core/arrays/integer.py

@@ -7,6 +7,7 @@
 from pandas._libs import lib, missing as libmissing
 from pandas._typing import ArrayLike
 from pandas.compat import set_function_name
+from pandas.compat.numpy import function as nv
 from pandas.util._decorators import cache_readonly
 
 from pandas.core.dtypes.base import ExtensionDtype
@@ -573,7 +574,19 @@ def _reduce(self, name: str, skipna: bool = True, **kwargs):
 
         return result
 
-    def sum(self, skipna: bool = True, min_count: int = 0):
+    def sum(
+        self,
+        axis=None,
+        dtype=None,
+        out=None,
+        keepdims=False,
+        initial=None,
+        skipna=True,
+        min_count=0,
+    ):
+        nv.validate_sum(
+            (), dict(dtype=dtype, out=out, keepdims=keepdims, initial=initial)
+        )
         result = masked_reductions.sum(
             values=self._data, mask=self._mask, skipna=skipna, min_count=min_count
         )

pandas/tests/arrays/integer/test_function.py

@@ -124,6 +124,15 @@ def test_integer_array_sum(skipna, min_count):
         assert result is pd.NA
 
 
+@pytest.mark.parametrize(
+    "values, expected", [([1, 2, 3], 6), ([1, 2, 3, None], 6), ([None], 0)]
+)
+def test_integer_array_numpy_sum(values, expected):
+    arr = pd.array(values, dtype="Int64")
+    result = np.sum(arr)
+    assert result == expected
+
+
 # TODO(jreback) - these need testing / are broken
 
 # shift