TST: differentiate 0 and np.nan (pandas-dev#35498)

Author: alexhlim

pandas/tests/indexes/test_indexing.py

@@ -120,6 +120,21 @@ def test_getitem_deprecated_float(idx):
             [NaT],
             np.array([1, 2], dtype=np.int64),
         ),
+        (
+            np.array([np.nan, 0, np.nan], dtype=object),
+            [np.nan],
+            np.array([0, 2], dtype=np.int64),
+        ),
+        (
+            np.array([np.nan, 0, np.nan], dtype=object),
+            [0],
+            np.array([1], dtype=np.int64),
+        ),
+        (
+            np.array([np.nan, 0, np.nan], dtype=object),
+            [np.nan, 0],
+            np.array([0, 2, 1], dtype=np.int64),
+        ),
     ],
 )
 def test_get_indexer_non_unique_multiple_nans(idx, target, expected):