Update groupby attrs tests (pydata#6787)

Co-authored-by: Anderson Banihirwe <[email protected]>

xarray/tests/test_groupby.py

@@ -1152,21 +1152,33 @@ def test_groupby_count(self):
         expected = DataArray([1, 1, 2], coords=[("cat", ["a", "b", "c"])])
         assert_identical(actual, expected)
 
-    @pytest.mark.skip("needs to be fixed for shortcut=False, keep_attrs=False")
-    def test_groupby_reduce_attrs(self):
+    @pytest.mark.parametrize("shortcut", [True, False])
+    @pytest.mark.parametrize("keep_attrs", [None, True, False])
+    def test_groupby_reduce_keep_attrs(self, shortcut, keep_attrs):
+        array = self.da
+        array.attrs["foo"] = "bar"
+
+        actual = array.groupby("abc").reduce(
+            np.mean, keep_attrs=keep_attrs, shortcut=shortcut
+        )
+        with xr.set_options(use_flox=False):
+            expected = array.groupby("abc").mean(keep_attrs=keep_attrs)
+        assert_identical(expected, actual)
+
+    @pytest.mark.parametrize("keep_attrs", [None, True, False])
+    def test_groupby_keep_attrs(self, keep_attrs):
         array = self.da
         array.attrs["foo"] = "bar"
 
-        for shortcut in [True, False]:
-            for keep_attrs in [True, False]:
-                print(f"shortcut={shortcut}, keep_attrs={keep_attrs}")
-                actual = array.groupby("abc").reduce(
-                    np.mean, keep_attrs=keep_attrs, shortcut=shortcut
-                )
-                expected = array.groupby("abc").mean()
-                if keep_attrs:
-                    expected.attrs["foo"] = "bar"
-                assert_identical(expected, actual)
+        with xr.set_options(use_flox=False):
+            expected = array.groupby("abc").mean(keep_attrs=keep_attrs)
+        with xr.set_options(use_flox=True):
+            actual = array.groupby("abc").mean(keep_attrs=keep_attrs)
+
+        # values are tested elsewhere, here we jsut check data
+        # TODO: add check_attrs kwarg to assert_allclose
+        actual.data = expected.data
+        assert_identical(expected, actual)
 
     def test_groupby_map_center(self):
         def center(x):