Hack to get sparse tests passing

Author: max-sixty

xarray/core/dataset.py

@@ -3713,7 +3713,6 @@ def _unstack_once_fast(self, dim: Hashable, fill_value, sparse: bool) -> "Datase
         for name, var in self.variables.items():
             if name != dim:
                 if dim in var.dims:
-                    # new_dims = dict(zip(new_dim_names, new_dim_sizes))
                     if isinstance(fill_value, Mapping):
                         fill_value_ = fill_value[name]
                     else:
@@ -3832,7 +3831,12 @@ def unstack(
 
         result = self.copy(deep=False)
         for dim in dims:
-            if sparse:
+            # FIXME: remove
+            import sparse as sparse_
+
+            if sparse or any(
+                isinstance(v.data, sparse_.COO) for v in self.variables.values()
+            ):
                 result = result._unstack_once(dim, fill_value, sparse)
             else:
                 result = result._unstack_once_fast(dim, fill_value, sparse)

xarray/core/variable.py

@@ -1597,8 +1597,6 @@ def _unstack_once_fast(
         new_shape = list(reordered.shape[: len(other_dims)]) + new_dim_sizes
         new_dims = reordered.dims[: len(other_dims)] + new_dim_names
 
-        # missing_values = np.prod(new_shape) > np.prod(self.shape)
-
         if fill_value is dtypes.NA:
             fill_value = dtypes.get_fill_value(self.dtype)