Raise Value Error for empty list. (#664)

* Raise Value Error for empty list

* Add check for empty line at begining of xyz

* Add test for empty line in xyz input

---------

Co-authored-by: Adam Grofe <[email protected]>

Author: adam-grofe

azure-quantum/azure/quantum/target/microsoft/elements/dft/target.py

@@ -79,6 +79,9 @@ def submit(self,
 
         if isinstance(input_data, list):
 
+            if len(input_data) < 1:
+                raise ValueError("Input data list has no elements.")
+
             if all(isinstance(task,str) for task in input_data):
                 qcschema_data = self.assemble_qcschema_from_files(input_data, input_params)
 
@@ -257,7 +260,7 @@ def _xyz_to_qcschema_mol(self, file_data: str ) -> Dict[str, Any]:
         """
 
         lines = file_data.split("\n")
-        if len(lines) < 3:
+        if len(lines) < 3 or not lines[0]:
             raise ValueError("Invalid xyz format.")
         n_atoms = int(lines.pop(0))
         comment = lines.pop(0)

azure-quantum/tests/unit/test_microsoft_elements_dft.py

@@ -332,14 +332,22 @@ def test_xyz_parsing_correct_xyz_files(data_regression, xyz_str):
 H   1.00   0.00   0.00
 H  -1.00   1.00   1.00
 H  -1.00   1.00   1.00  -0.6
+""",
+        """
+3
+water
+O   0.00   0.00   0.00
+H   1.00   0.00   0.00
+H  -1.00   1.00   1.00
 """,
     ],
     ids=[
         'atom_missing',
         'atom_on_previous_line',
         'empty_line_in_middle',
         'duplicated_line',
-        'mm_atom_without_dash'
+        'mm_atom_without_dash',
+        'empty_line_at_beginning'
     ]
 )
 def test_xyz_raises_for_bad_input(xyz_str):