Restore slow warning for _apply_everywhere and _cube_on_cube_operation

spectral_cube/tests/test_spectral_cube.py

@@ -109,10 +109,12 @@ def test_arithmetic_warning(data_vda_jybeam_lower, recwarn, use_dask):
 
     assert not cube._is_huge
 
-    if not use_dask:
-        # make sure the small cube raises a warning about loading into memory
-        with pytest.warns(UserWarning, match='requires loading the entire'):
-            cube + 5*cube.unit
+    # make sure the small cube raises a warning about loading into memory
+    with pytest.warns(UserWarning, match='requires loading the entire'):
+        cube + 5*cube.unit
+
+    with pytest.warns(UserWarning, match='requires loading the entire'):
+        cube + cube
 
 
 def test_huge_disallowed(data_vda_jybeam_lower, use_dask):

spectral_cube/utils.py

@@ -38,7 +38,12 @@ def wrapper(self, *args, **kwargs):
         accepts_how_keyword = 'how' in argspec.args or argspec.varkw == 'how'
 
         warn_how = accepts_how_keyword and ((kwargs.get('how') == 'cube') or 'how' not in kwargs)
-
+
+        # This restores showing the "loading the entire cube into memory" warning for
+        # _apply_everywhere and _cube_on_cube_operation
+        if function.__name__ in ['_apply_everywhere', '_cube_on_cube_operation']:
+            warn_how = True
+
         if self._is_huge and not self.allow_huge_operations:
             warn_message = ("This function ({0}) requires loading the entire "
                             "cube into memory, and the cube is large ({1} "
@@ -50,7 +55,7 @@ def wrapper(self, *args, **kwargs):
                 warn_message += ("Alternatively, you may want to consider using an "
                                  "approach that does not load the whole cube into "
                                  "memory by specifying how='slice' or how='ray'.  ")
-            
+
             warn_message += ("See {bigdataurl} for details.".format(bigdataurl=bigdataurl))
 
             raise ValueError(warn_message)