Added changes and new test file

Author: Gnot727

pandas/core/algorithms.py

@@ -1703,11 +1703,11 @@ def mapper_check(x):
             if x is None:
                 return pd.NA
             else:
-                mapper(x)
+                return mapper(x)
         values = arr.copy()
 
         if na_action is None:
             #return lib.map_infer(values, mapper)
-            return np.array([mapper_check(x) for x in values], dtype = arr.dtype)
+            return pd.array([mapper_check(x) for x in values], dtype = arr.dtype)
         else:
             return lib.map_infer_mask(values, mapper, mask=isna(values).view(np.uint8))

pandas/core/series.py

@@ -4626,7 +4626,7 @@ def apply_check(val):
             if val is None:
                 return pd.NA
             return val
-        func = functools.partial(apply_check,func)
+        self = [apply_check(x) for x in self]
 
         #proceed with usual apply method 
         return SeriesApply(

pandas/tests/apply/test_series_apply_bugFix.py

@@ -0,0 +1,45 @@
+import numpy as np
+import pytest
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Index,
+    MultiIndex,
+    Series,
+    concat,
+    date_range,
+    timedelta_range,
+)
+import pandas._testing as tm
+from pandas.tests.apply.common import series_transform_kernels
+
+def test_series_map_NAinteger():
+    s = pd.Series([1,2,None],dtype="Int32")
+
+    def increment(x):
+        if x is None:
+            return pd.NA
+        return x+1
+
+       
+    result = s.map(increment)
+
+    expectedResult = pd.Series([2,3,pd.NA],dtype = "Int32")
+
+    pd.testing.assert_series_equal(result,expectedResult)
+
+def test_series_apply_NAinteger():
+    s = pd.Series([1,2,None],dtype="Int32")
+
+    def increment(x):
+        if x is None:
+            return pd.NA
+        return x+1
+
+       
+    result = s.apply(increment)
+
+    expectedResult = pd.Series([2,3,pd.NA],dtype = "Int32")
+
+    pd.testing.assert_series_equal(result,expectedResult)