Fix binning by dimension coordinate

Author: dcherian

dask_groupby/xarray.py

@@ -175,9 +175,8 @@ def xarray_reduce(
     ds = ds.drop_vars([var for var in maybe_drop if var in ds.variables])
     if dim is Ellipsis:
         dim = tuple(obj.dims)
-        if by[0].name in ds.dims:
+        if by[0].name in ds.dims and not isbin[0]:
             dim = tuple(d for d in dim if d != by[0].name)
-        dim = tuple(dim)
 
     # TODO: do this for specific reductions only
     bad_dtypes = tuple(
@@ -203,14 +202,16 @@ def xarray_reduce(
         raise ValueError(f"cannot reduce over dimensions {dim}")
 
     dims_not_in_groupers = tuple(d for d in dim if d not in grouper_dims)
-    if dims_not_in_groupers == dim:
+    if dims_not_in_groupers == dim and not any(isbin):
         # reducing along a dimension along which groups do not vary
         # This is really just a normal reduction.
+        # This is not right when binning so we exclude.
         if skipna:
             dsfunc = func[3:]
         else:
             dsfunc = func
-        result = getattr(ds, dsfunc)(dim=dim)
+        # TODO: skipna needs test
+        result = getattr(ds, dsfunc)(dim=dim, skipna=skipna)
         if isinstance(obj, xr.DataArray):
             return obj._from_temp_dataset(result)
         else:

tests/test_xarray.py

@@ -290,8 +290,16 @@ def test_xarray_groupby_bins(chunks):
     )
     xr.testing.assert_equal(actual, expected)
 
-    # TODO: fix this test
-    # expected_xr = array.groupby_bins(labels, bins=[1, 2, 4, 5]).count().fillna(0)
+    # TODO: fix this test?
+    # expected_xr = array.groupby_bins(labels, bins=[1, 2, 4, 5]).count() #.fillna(0)
     # xr.testing.assert_equal(actual, expected_xr)
 
+    da = xr.DataArray(np.random.randn(2, 3, 4))
+    bins = [-1, 0, 1, 2]
+    with xr.set_options(use_numpy_groupies=False):
+        actual = da.groupby_bins("dim_0", bins).mean(...)
+    with xr.set_options(use_numpy_groupies=True):
+        expected = da.groupby_bins("dim_0", bins).mean(...)
+        xr.testing.assert_allclose(actual, expected)
+
     # TODO: test cut_kwargs