TST/REF: collect mask tests

pandas/tests/indexes/multi/test_reshape.py

@@ -71,6 +71,8 @@ def test_insert(idx):
     tm.assert_frame_equal(left, right, check_dtype=False)
     tm.assert_series_equal(ts, right["3rd"])
 
+
+def test_insert2():
     # GH9250
     idx = (
         [("test1", i) for i in range(5)]

pandas/tests/indexing/test_indexing.py

@@ -712,8 +712,8 @@ def test_str_label_slicing_with_negative_step(self):
                 ser, SLC[idx[9] : idx[13] : -1], SLC[:0]
             )
 
-    def test_slice_with_zero_step_raises(self, indexer_sl, frame_or_series):
-        obj = frame_or_series(np.arange(20), index=_mklbl("A", 20))
+    def test_slice_with_zero_step_raises(self, index, indexer_sl, frame_or_series):
+        obj = frame_or_series(np.arange(len(index)), index=index)
         with pytest.raises(ValueError, match="slice step cannot be zero"):
             indexer_sl(obj)[::0]
 

pandas/tests/series/indexing/test_indexing.py

@@ -262,48 +262,6 @@ def test_preserve_refs(datetime_series):
     assert not np.isnan(datetime_series[10])
 
 
-def test_cast_on_putmask():
-    # GH 2746
-
-    # need to upcast
-    s = Series([1, 2], index=[1, 2], dtype="int64")
-    s[[True, False]] = Series([0], index=[1], dtype="int64")
-    expected = Series([0, 2], index=[1, 2], dtype="int64")
-
-    tm.assert_series_equal(s, expected)
-
-
-def test_type_promote_putmask():
-    # GH8387: test that changing types does not break alignment
-    ts = Series(np.random.randn(100), index=np.arange(100, 0, -1)).round(5)
-    left, mask = ts.copy(), ts > 0
-    right = ts[mask].copy().map(str)
-    left[mask] = right
-    tm.assert_series_equal(left, ts.map(lambda t: str(t) if t > 0 else t))
-
-
-def test_setitem_mask_promote_strs():
-
-    ser = Series([0, 1, 2, 0])
-    mask = ser > 0
-    ser2 = ser[mask].map(str)
-    ser[mask] = ser2
-
-    expected = Series([0, "1", "2", 0])
-    tm.assert_series_equal(ser, expected)
-
-
-def test_setitem_mask_promote():
-
-    ser = Series([0, "foo", "bar", 0])
-    mask = Series([False, True, True, False])
-    ser2 = ser[mask]
-    ser[mask] = ser2
-
-    expected = Series([0, "foo", "bar", 0])
-    tm.assert_series_equal(ser, expected)
-
-
 def test_multilevel_preserve_name(lexsorted_two_level_string_multiindex, indexer_sl):
     index = lexsorted_two_level_string_multiindex
     ser = Series(np.random.randn(len(index)), index=index, name="sth")
@@ -317,13 +275,6 @@ def test_multilevel_preserve_name(lexsorted_two_level_string_multiindex, indexer
 """
 
 
-def test_slice_with_zero_step_raises(index, frame_or_series, indexer_sli):
-    ts = frame_or_series(np.arange(len(index)), index=index)
-
-    with pytest.raises(ValueError, match="slice step cannot be zero"):
-        indexer_sli(ts)[::0]
-
-
 @pytest.mark.parametrize(
     "index",
     [

pandas/tests/series/indexing/test_mask.py

@@ -37,15 +37,19 @@ def test_mask():
     with pytest.raises(ValueError, match=msg):
         s.mask(cond[:3].values, -s)
 
+
+def test_mask_casts():
     # dtype changes
-    s = Series([1, 2, 3, 4])
-    result = s.mask(s > 2, np.nan)
+    ser = Series([1, 2, 3, 4])
+    result = ser.mask(ser > 2, np.nan)
     expected = Series([1, 2, np.nan, np.nan])
     tm.assert_series_equal(result, expected)
 
+
+def test_mask_casts2():
     # see gh-21891
-    s = Series([1, 2])
-    res = s.mask([True, False])
+    ser = Series([1, 2])
+    res = ser.mask([True, False])
 
     exp = Series([np.nan, 2])
     tm.assert_series_equal(res, exp)

pandas/tests/series/indexing/test_setitem.py

@@ -234,6 +234,43 @@ def test_setitem_multiindex_slice(self, indexer_sli):
 
 
 class TestSetitemBooleanMask:
+    def test_setitem_mask_cast(self):
+        # GH#2746
+        # need to upcast
+        ser = Series([1, 2], index=[1, 2], dtype="int64")
+        ser[[True, False]] = Series([0], index=[1], dtype="int64")
+        expected = Series([0, 2], index=[1, 2], dtype="int64")
+
+        tm.assert_series_equal(ser, expected)
+
+    def test_setitem_mask_align_and_promote(self):
+        # GH#8387: test that changing types does not break alignment
+        ts = Series(np.random.randn(100), index=np.arange(100, 0, -1)).round(5)
+        mask = ts > 0
+        left = ts.copy()
+        right = ts[mask].copy().map(str)
+        left[mask] = right
+        expected = ts.map(lambda t: str(t) if t > 0 else t)
+        tm.assert_series_equal(left, expected)
+
+    def test_setitem_mask_promote_strs(self):
+        ser = Series([0, 1, 2, 0])
+        mask = ser > 0
+        ser2 = ser[mask].map(str)
+        ser[mask] = ser2
+
+        expected = Series([0, "1", "2", 0])
+        tm.assert_series_equal(ser, expected)
+
+    def test_setitem_mask_promote(self):
+        ser = Series([0, "foo", "bar", 0])
+        mask = Series([False, True, True, False])
+        ser2 = ser[mask]
+        ser[mask] = ser2
+
+        expected = Series([0, "foo", "bar", 0])
+        tm.assert_series_equal(ser, expected)
+
     def test_setitem_boolean(self, string_series):
         mask = string_series > string_series.median()