Test merge with EA as key and open a special case

Author: makbigc

pandas/tests/extension/base/reshaping.py

@@ -173,18 +173,17 @@ def test_merge(self, data, na_value):
                  dtype=data.dtype)})
         self.assert_frame_equal(res, exp[['ext', 'int1', 'key', 'int2']])
 
-    @pytest.mark.parametrize("dtypes", ["Int8", "Int16", "Int32", "Int64",
-                                        "UInt8", "UInt16", "UInt32", "UInt64"])
-    def test_merge_on_int_array(self, data, dtypes):
-        # GH  23020
-        df1 = pd.DataFrame({'ext': data[:3],
-                            'key': pd.Series([1, 2, np.nan], dtype=dtypes)})
+    def test_merge_on_extension_array(self, data):
+        # GH 23020
+        df1 = pd.DataFrame({'ext': [1, 2, 3],
+                            'key': data[:3]})
+
         res = pd.merge(df1, df1, on='key')
 
         exp = pd.DataFrame(
-            {'key': pd.Series([1, 2, np.nan], dtype=dtypes),
-             'ext_x': data._from_sequence(data[:3], dtype=data.dtype),
-             'ext_y': data._from_sequence(data[:3], dtype=data.dtype)})
+            {'key': data[:3],
+             'ext_x': [1, 2, 3],
+             'ext_y': [1, 2, 3]})
 
         self.assert_frame_equal(res, exp[['ext_x', 'key', 'ext_y']],
                                 check_dtype=True)

pandas/tests/reshape/merge/test_merge.py

@@ -1326,6 +1326,16 @@ def test_merging_with_bool_or_int_cateorical_column(self, category_column,
             CDT(categories, ordered=ordered))
         assert_frame_equal(expected, result)
 
+    def test_merge_on_int_array(self):
+        # GH 23020
+        df = pd.DataFrame({'A': pd.Series([1, 2, np.nan], dtype='Int64'),
+                           'B': 1})
+        result = pd.merge(df, df, on='A')
+        expected = pd.DataFrame({'A': pd.Series([1, 2, np.nan], dtype='Int64'),
+                                 'B_x': 1,
+                                 'B_y': 1})
+        assert_frame_equal(result, expected, check_dtype=True)
+
 
 @pytest.fixture
 def left_df():