Add schema_features property to parsers for version detection

Author: koxudaxi

src/datamodel_code_generator/parser/jsonschema.py

@@ -28,6 +28,7 @@
     AllOfClassHierarchy,
     AllOfMergeMode,
     InvalidClassNameError,
+    JsonSchemaVersion,
     ReadOnlyWriteOnlyModelType,
     SchemaParseError,
     YamlValue,
@@ -87,6 +88,7 @@
 
     from datamodel_code_generator._types import JSONSchemaParserConfigDict
     from datamodel_code_generator.config import JSONSchemaParserConfig
+    from datamodel_code_generator.parser.schema_version import JsonSchemaFeatures
 
 
 def unescape_json_pointer_segment(segment: str) -> str:
@@ -769,6 +771,17 @@ def schema_paths(self) -> list[tuple[str, list[str]]]:
         """Get schema paths for definitions and defs."""
         return [(s, s.lstrip("#/").split("/")) for s in self.SCHEMA_PATHS]
 
+    @cached_property
+    def schema_features(self) -> JsonSchemaFeatures:
+        """Get schema features based on detected version."""
+        from datamodel_code_generator.parser.schema_version import (  # noqa: PLC0415
+            JsonSchemaFeatures,
+            detect_jsonschema_version,
+        )
+
+        version = detect_jsonschema_version(self.raw_obj) if self.raw_obj else JsonSchemaVersion.Auto
+        return JsonSchemaFeatures.from_version(version)
+
     @property
     def root_id(self) -> str | None:
         """Get the root $id from the model resolver."""

src/datamodel_code_generator/parser/openapi.py

@@ -11,6 +11,7 @@
 from collections import defaultdict
 from contextlib import nullcontext
 from enum import Enum
+from functools import cached_property
 from pathlib import Path
 from re import Pattern
 from typing import TYPE_CHECKING, Any, ClassVar, Optional, TypeVar, Union
@@ -26,6 +27,7 @@
     load_data,
     snooper_to_methods,
 )
+from datamodel_code_generator.enums import OpenAPIVersion
 from datamodel_code_generator.parser.base import get_special_path
 from datamodel_code_generator.parser.jsonschema import (
     JsonSchemaObject,
@@ -45,6 +47,7 @@
     from datamodel_code_generator._types import OpenAPIParserConfigDict
     from datamodel_code_generator.config import OpenAPIParserConfig
     from datamodel_code_generator.model import DataModelFieldBase
+    from datamodel_code_generator.parser.schema_version import OpenAPISchemaFeatures
 
 
 RE_APPLICATION_JSON_PATTERN: Pattern[str] = re.compile(r"^application/.*json$")
@@ -167,6 +170,17 @@ class OpenAPIParser(JsonSchemaParser):
 
     SCHEMA_PATHS: ClassVar[list[str]] = ["#/components/schemas"]
 
+    @cached_property
+    def schema_features(self) -> OpenAPISchemaFeatures:
+        """Get schema features based on detected OpenAPI version."""
+        from datamodel_code_generator.parser.schema_version import (  # noqa: PLC0415
+            OpenAPISchemaFeatures,
+            detect_openapi_version,
+        )
+
+        version = detect_openapi_version(self.raw_obj) if self.raw_obj else OpenAPIVersion.Auto
+        return OpenAPISchemaFeatures.from_openapi_version(version)
+
     @classmethod
     def _create_default_config(cls, options: OpenAPIParserConfigDict) -> OpenAPIParserConfig:
         """Create an OpenAPIParserConfig from options."""

tests/parser/test_schema_version.py

@@ -399,3 +399,25 @@ def test_get_data_formats_openapi() -> None:
         "null": {"default": Types.null},
         "array": {"default": Types.array},
     })
+
+
+def test_jsonschema_parser_schema_features_detection() -> None:
+    """Test that JsonSchemaParser detects schema version from $schema."""
+    from datamodel_code_generator.parser.jsonschema import JsonSchemaParser
+
+    parser = JsonSchemaParser("")
+    parser.raw_obj = {"$schema": "http://json-schema.org/draft-07/schema#"}
+    features = parser.schema_features
+    assert features.boolean_schemas == snapshot(True)
+    assert features.definitions_key == snapshot("definitions")
+
+
+def test_openapi_parser_schema_features_detection() -> None:
+    """Test that OpenAPIParser detects OpenAPI version from openapi field."""
+    from datamodel_code_generator.parser.openapi import OpenAPIParser
+
+    parser = OpenAPIParser("")
+    parser.raw_obj = {"openapi": "3.1.0"}
+    features = parser.schema_features
+    assert features.nullable_keyword == snapshot(False)
+    assert features.null_in_type_array == snapshot(True)