Improve error handling and add test

Author: jacob720

src/daq_config_server/models/converters/lookup_tables/_models.py

@@ -69,7 +69,12 @@ def get_value(
         return target_row[target_column_index]
 
     def get_column(self, column_name: ColumnNameT) -> list[int | float]:
-        column_index = self.get_column_names().index(column_name)
+        try:
+            column_index = self.get_column_names().index(column_name)
+        except ValueError as e:
+            raise ValueError(
+                f"'{column_name}' not in column names: {self.get_column_names()}"
+            ) from e
         return self.columns[column_index]
 
     @abstractmethod

tests/unit_tests/converters/test_lookup_tables_converters.py

@@ -205,3 +205,14 @@ def test_get_column(generic_lookup_table: GenericLookupTable):
     assert generic_lookup_table.get_column("detector_distance_mm") == [150, 800]
     assert generic_lookup_table.get_column("beam_centre_x_mm") == [152.2, 152.08]
     assert generic_lookup_table.get_column("beam_centre_y_mm") == [166.26, 160.96]
+
+
+def test_get_column_with_invalid_column_name(generic_lookup_table: GenericLookupTable):
+    with pytest.raises(
+        ValueError,
+        match=re.escape(
+            "'column_name' not in column names: "
+            + "['detector_distance_mm', 'beam_centre_x_mm', 'beam_centre_y_mm']",
+        ),
+    ):
+        assert generic_lookup_table.get_column("column_name") == [150, 800]