[core] feat: add support for parsing resource_index and nested_field customizers

Author: AndreyMarkinPPC

libs/core/garf_core/parsers.py

@@ -130,12 +130,43 @@ def process_customizer(
   ) -> api_clients.ApiRowElement:
     if customizer.type == 'slice':
       return self._process_customizer_slice(row, customizer, field)
+    if customizer.type == 'nested_field':
+      return self._process_nested_field(row, customizer, field)
+    if customizer.type == 'resource_index':
+      return self._process_resource_index(row, customizer, field)
     return row
 
   def _process_customizer_slice(self, row, customizer, field):
     slice_object = customizer.value.slice_literal
     return [r.get(customizer.value.value) for r in row.get(field)[slice_object]]
 
+  def _process_nested_field(self, row, customizer, field):
+    nested_field = row.get(field)
+    try:
+      return operator.attrgetter(customizer.value)(nested_field)
+    except AttributeError as e:
+      raise query_parser.GarfCustomizerError(
+        f'nested field {customizer.value} is missing in row {row}'
+      ) from e
+
+  def _process_resource_index(self, row, customizer, field):
+    resource = row.get(field, '/')
+    _, *elements = row.get(field, '/').split('/')
+    if not elements:
+      raise query_parser.GarfCustomizerError(
+        f'Not a valid resource: {resource}'
+      )
+    resource_elements = elements[-1].split('~')
+    try:
+      try:
+        return int(resource_elements[customizer.value])
+      except ValueError:
+        return resource_elements[customizer.value]
+    except IndexError as e:
+      raise query_parser.GarfCustomizerError(
+        'Not a valid position in resource: %s, %d', resource, customizer.value
+      ) from e
+
   def parse_row(
     self,
     row: api_clients.ApiResponseRow,

libs/core/garf_core/query_parser.py

@@ -58,7 +58,7 @@ class Customizer(pydantic.BaseModel):
 
   def __bool__(self) -> bool:
     """Evaluates whether all fields are not empty."""
-    return bool(self.type and self.value)
+    return bool(self.type and self.value is not None)
 
 
 class SliceField(pydantic.BaseModel):

libs/core/tests/unit/test_parsers.py

@@ -12,14 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pydantic
 import pytest
-from garf_core import api_clients, parsers, query_editor
+from garf_core import api_clients, parsers, query_editor, query_parser
 
 test_specification = query_editor.QuerySpecification(
   'SELECT test_column_1 FROM test'
 ).generate()
 
 
+class NestedResource(pydantic.BaseModel):
+  nested_element: int
+
+
 class TestDictParser:
   @pytest.fixture
   def test_parser(self):
@@ -117,6 +122,90 @@ def test_parse_response_returns_correct_result_for_arrays(
 
     assert parsed_row == expected_row
 
+  @pytest.mark.parametrize(
+    ('index', 'expected'),
+    [
+      ('0', [[0], [1]]),
+      ('1', [['TEXT'], ['IMAGE']]),
+      ('2', [[54321], [12345]]),
+    ],
+  )
+  def test_parse_response_returns_correct_resource_index(self, index, expected):
+    spec = query_editor.QuerySpecification(
+      text=f'SELECT resource~{index} AS column FROM test'
+    ).generate()
+    test_parser = parsers.DictParser(spec)
+    test_response = api_clients.GarfApiResponse(
+      results=[
+        {'resource': 'resource/1/test/0~TEXT~54321'},
+        {'resource': 'resource/1/test/1~IMAGE~12345'},
+      ]
+    )
+    parsed_row = test_parser.parse_response(test_response)
+    assert parsed_row == expected
+
+  def test_parse_response_raises_customizer_error_on_invalid_position(self):
+    spec = query_editor.QuerySpecification(
+      text='SELECT resource~4 AS column FROM test'
+    ).generate()
+    test_parser = parsers.DictParser(spec)
+    test_response = api_clients.GarfApiResponse(
+      results=[
+        {'resource': 'resource/1/test/0~TEXT~54321'},
+      ]
+    )
+    with pytest.raises(
+      query_parser.GarfCustomizerError, match='Not a valid position in resource'
+    ):
+      test_parser.parse_response(test_response)
+
+  def test_parse_response_raises_customizer_error_on_invalid_resource(self):
+    spec = query_editor.QuerySpecification(
+      text='SELECT resource~0 AS column FROM test'
+    ).generate()
+    test_parser = parsers.DictParser(spec)
+    test_response = api_clients.GarfApiResponse(
+      results=[
+        {'resource': 'resource'},
+      ]
+    )
+    with pytest.raises(
+      query_parser.GarfCustomizerError, match='Not a valid resource'
+    ):
+      test_parser.parse_response(test_response)
+
+  def test_parse_response_returns_correct_nested_attribute(self):
+    spec = query_editor.QuerySpecification(
+      text='SELECT resource:nested_element AS column FROM test'
+    ).generate()
+    test_parser = parsers.DictParser(spec)
+    test_response = api_clients.GarfApiResponse(
+      results=[
+        {'resource': NestedResource(nested_element=1)},
+        {'resource': NestedResource(nested_element=2)},
+      ]
+    )
+    parsed_row = test_parser.parse_response(test_response)
+    assert parsed_row == [[1], [2]]
+
+  def test_parse_response_raises_customizer_error_on_missing_nested_attribute(
+    self,
+  ):
+    spec = query_editor.QuerySpecification(
+      text='SELECT resource:missing_element AS column FROM test'
+    ).generate()
+    test_parser = parsers.DictParser(spec)
+    test_response = api_clients.GarfApiResponse(
+      results=[
+        {'resource': NestedResource(nested_element=1)},
+      ]
+    )
+    with pytest.raises(
+      query_parser.GarfCustomizerError,
+      match='nested field missing_element is missing in row',
+    ):
+      test_parser.parse_response(test_response)
+
   def test_parse_response_skips_omitted_columns(self):
     test_specification = query_editor.QuerySpecification(
       'SELECT test_column_1 AS _, test_column_2 FROM test'