rdkit_phys_chem: raise when an empty descriptor list is provided (#160)

Author: JochenSiegWork

molpipeline/mol2any/mol2rdkit_phys_chem.py

@@ -105,10 +105,16 @@ def descriptor_list(self, descriptor_list: list[str] | None) -> None:
         ------
         ValueError
             If an unknown descriptor name is used.
+        ValueError
+            If an empty descriptor_list is used.
         """
         if descriptor_list is None or descriptor_list is DEFAULT_DESCRIPTORS:
             # if None or DEFAULT_DESCRIPTORS are used, set the default descriptors
             self._descriptor_list = DEFAULT_DESCRIPTORS
+        elif len(descriptor_list) == 0:
+            raise ValueError(
+                "Empty descriptor_list is not allowed. Use None for default descriptors."
+            )
         else:
             # check all user defined descriptors are valid
             for descriptor_name in descriptor_list:

tests/test_elements/test_mol2any/test_mol2rdkit_phys_chem.py

@@ -403,6 +403,14 @@ def test_exception_handling(self) -> None:
         output = pipeline.fit_transform(["[HH]"])
         self.assertTrue(output.shape == (1, len(DEFAULT_DESCRIPTORS)))
 
+    def test_empty_descriptor_list(self) -> None:
+        """Test that an empty descriptor list raises ValueError."""
+        with self.assertRaises(ValueError) as context:
+            MolToRDKitPhysChem(descriptor_list=[])
+        self.assertTrue(
+            str(context.exception).startswith("Empty descriptor_list is not allowed")
+        )
+
 
 if __name__ == "__main__":
     unittest.main()