[core] feat: Add support for built-in queries

libs/garf_core/garf_core/query_editor.py

@@ -53,6 +53,10 @@ class GarfResourceError(GarfQueryError):
   """Specifies incorrect resource name in the query."""
 
 
+class GarfBuiltInQueryError(GarfQueryError):
+  """Specifies non-existing builtin query."""
+
+
 @dataclasses.dataclass
 class ProcessedField:
   """Helper class to store fields with its customizers.
@@ -383,19 +387,24 @@ def macros(self) -> dict[str, str]:
     return common_params
 
   def generate(self) -> BaseQueryElements:
-    return (
-      self.remove_comments()
-      .expand()
-      .extract_resource_name()
-      .remove_trailing_comma()
+    self.remove_comments().expand().extract_resource_name()
+    if self.query.resource_name.startswith('builtin'):
+      return BaseQueryElements(
+        title=self.query.resource_name.replace('builtin.', ''),
+        text=self.query.text,
+        resource_name=self.query.resource_name,
+        is_builtin_query=True,
+      )
+    (
+      self.remove_trailing_comma()
       .extract_fields()
       .extract_filters()
       .extract_sorts()
       .extract_column_names()
       .extract_virtual_columns()
       .extract_customizers()
-      .query
     )
+    return self.query
 
   def expand(self) -> Self:
     """Applies necessary transformations to query."""

libs/garf_core/garf_core/report_fetcher.py

@@ -11,17 +11,19 @@
 # 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.
+
+# pylint: disable=C0330, g-bad-import-order, g-multiple-import
+
 """Module for getting data from API based on a query.
 
 ApiReportFetcher performs fetching data from API, parsing it
   and returning GarfReport.
 """
-# pylint: disable=C0330, g-bad-import-order, g-multiple-import
 
 from __future__ import annotations
 
 import logging
-from typing import Any
+from typing import Any, Callable
 
 from garf_core import (
   api_clients,
@@ -49,6 +51,8 @@ def __init__(
     query_specification_builder: query_editor.QuerySpecification = (
       query_editor.QuerySpecification
     ),
+    builtin_queries: dict[str, Callable[[ApiReportFetcher], report.GarfReport]]
+    | None = None,
     **kwargs: str,
   ) -> None:
     """Instantiates ApiReportFetcher based on provided api client.
@@ -57,11 +61,21 @@ def __init__(
       api_client: Instantiated api client.
       parser: Type of parser to convert API response.
       query_specification_builder: Class to perform query parsing.
+      builtin_queries:
+        Mapping between query name and function for generating GarfReport.
     """
     self.api_client = api_client
     self.parser = parser()
     self.query_specification_builder = query_specification_builder
     self.query_args = kwargs
+    self.builtin_queries = builtin_queries or {}
+
+  def add_builtin_queries(
+    self,
+    builtin_queries: dict[str, Callable[[ApiReportFetcher], report.GarfReport]],
+  ) -> None:
+    """Adds new built-in queries to the fetcher."""
+    self.builtin_queries.update(builtin_queries)
 
   async def afetch(
     self,
@@ -107,6 +121,13 @@ def fetch(
         args=args,
       )
     query = query_specification.generate()
+    if query.is_builtin_query:
+      if not (builtin_report := self.builtin_queries.get(query.title)):
+        raise query_editor.GarfBuiltInQueryError(
+          f'Cannot find the built-in query "{query.title}"'
+        )
+      return builtin_report(self, **kwargs)
+
     response = self.api_client.get_response(query, **kwargs)
     parsed_response = self.parser.parse_response(response, query)
     return report.GarfReport(

libs/garf_core/tests/unit/test_query_editor.py

@@ -90,3 +90,16 @@ def test_generate_returns_correct(self, query):
     )
 
     assert test_query_spec.query == expected_query_elements
+
+  def test_generate_returns_builtin_query(self):
+    query = 'SELECT test FROM builtin.test'
+    test_query_spec = query_editor.QuerySpecification(text=query, title='test')
+    test_query_spec.generate()
+    expected_query_elements = query_editor.BaseQueryElements(
+      title='test',
+      text=query,
+      resource_name='builtin.test',
+      is_builtin_query=True,
+    )
+
+    assert test_query_spec.query == expected_query_elements

libs/garf_core/tests/unit/test_report_fetcher.py

@@ -68,3 +68,18 @@ def test_fetch_returns_correct_report_for_dict_parser(
     )
 
     assert test_report == expected_report
+
+  def test_fetch_builtin_query_returns_correct_builtin_report(
+    self, test_dict_report_fetcher
+  ):
+    test_report = report.GarfReport(results=[[1]], column_names=['test'])
+
+    def test_builtin_query(report_fetcher):
+      return test_report
+
+    test_dict_report_fetcher.add_builtin_queries({'test': test_builtin_query})
+
+    query = 'SELECT test FROM builtin.test'
+    fetched_report = test_dict_report_fetcher.fetch(query, None)
+
+    assert fetched_report == test_report