[core] chore: dipslay virtual column value when raising GarfVirtualColumnError

Author: AndreyMarkinPPC

libs/core/garf_core/query_parser.py

@@ -238,8 +238,8 @@ class ExtractedLineElements(pydantic.BaseModel):
 
   field: str | None
   alias: str | None
-  virtual_column: VirtualColumn | None
-  customizer: Customizer | None
+  virtual_column: VirtualColumn | None = None
+  customizer: Customizer | None = None
 
   @classmethod
   def from_query_line(
@@ -260,7 +260,9 @@ def from_query_line(
     if not (customizer := processed_field.customizer):
       customizer = None
     if virtual_column and not alias:
-      raise GarfVirtualColumnError('Virtual attributes should be aliased')
+      raise GarfVirtualColumnError(
+        f'Virtual attributes should be aliased: {virtual_column.value}'
+      )
     return ExtractedLineElements(
       field=_format_type_field_name(field)
       if not virtual_column and field

libs/core/tests/unit/test_query_parser.py

@@ -0,0 +1,85 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+from garf_core.query_parser import (
+  Customizer,
+  ExtractedLineElements,
+  GarfVirtualColumnError,
+  SliceField,
+  VirtualColumn,
+)
+
+
+class TestExtractedLineElemens:
+  @pytest.mark.parametrize(
+    ('line', 'expected'),
+    [
+      (
+        'field AS column',
+        ExtractedLineElements(field='field', alias='column'),
+      ),
+      (
+        'field',
+        ExtractedLineElements(field='field', alias='field'),
+      ),
+      (
+        '1 + 1 AS column',
+        ExtractedLineElements(
+          field=None,
+          alias='column',
+          virtual_column=VirtualColumn(
+            type='expression',
+            value='1 + 1',
+            fields=[],
+            substitute_expression='1 + 1',
+          ),
+        ),
+      ),
+      (
+        'field + 1 AS column',
+        ExtractedLineElements(
+          field=None,
+          alias='column',
+          virtual_column=VirtualColumn(
+            type='expression',
+            value='field + 1',
+            fields=['field'],
+            substitute_expression='{field} + 1',
+          ),
+        ),
+      ),
+      (
+        'field[0].value AS column',
+        ExtractedLineElements(
+          field='field',
+          alias='column',
+          customizer=Customizer(
+            type='slice',
+            value=SliceField(slice_literal=slice(0, 1, None), value='value'),
+          ),
+        ),
+      ),
+    ],
+  )
+  def test_from_query_line_returns_correct_elements(self, line, expected):
+    elements = ExtractedLineElements.from_query_line(line)
+    assert elements == expected
+
+  def test_from_query_line_raises_error_on_unaliased_virtual_column(self):
+    with pytest.raises(
+      GarfVirtualColumnError,
+      match='Virtual attributes should be aliased: 1',
+    ):
+      ExtractedLineElements.from_query_line('1')