koxudaxi/datamodel-code-generator 0.53.0 on GitHub

Breaking Changes

Custom Template Update Required

Parser subclass signature change - The Parser base class now requires two generic type parameters: Parser[ParserConfigT, SchemaFeaturesT] instead of just Parser[ParserConfigT]. Custom parser subclasses must be updated to include the second type parameter. (#2929)
```
# Before
class MyCustomParser(Parser["MyParserConfig"]):
    ...
# After
class MyCustomParser(Parser["MyParserConfig", "JsonSchemaFeatures"]):
    ...
```

New abstract schema_features property required - Custom parser subclasses must now implement the schema_features abstract property that returns a JsonSchemaFeatures (or subclass) instance. (#2929)

from functools import cached_property
from datamodel_code_generator.parser.schema_version import JsonSchemaFeatures
from datamodel_code_generator.enums import JsonSchemaVersion
class MyCustomParser(Parser["MyParserConfig", "JsonSchemaFeatures"]):
    @cached_property
    def schema_features(self) -> JsonSchemaFeatures:
        return JsonSchemaFeatures.from_version(JsonSchemaVersion.Draft202012)

Parser _create_default_config refactored to use class variable - Subclasses that override _create_default_config should now set the _config_class_name class variable instead. The base implementation uses this variable to dynamically instantiate the correct config class. (#2929)

# Before
@classmethod
def _create_default_config(cls, options: MyConfigDict) -> MyParserConfig:
    # custom implementation...
# After
_config_class_name: ClassVar[str] = "MyParserConfig"
# No need to override _create_default_config if using standard config creation

Template condition for default values changed - If you use custom Jinja2 templates based on BaseModel_root.jinja2 or RootModel.jinja2, the condition for including default values has changed from field.required to (field.required and not field.has_default). Update your custom templates if you override these files. (#2960)

Code Generation Changes

RootModel default values now included in generated code - Previously, default values defined in JSON Schema or OpenAPI specifications for root models were not being applied to the generated Pydantic code. Now these defaults are correctly included. For example, a schema defining a root model with default: 1 will generate __root__: int = 1 (Pydantic v1) or root: int = 1 (Pydantic v2) instead of just __root__: int or root: int. This may affect code that relied on the previous behavior where RootModel fields had no default values. (#2960)
Required fields with list defaults now use default_factory - Previously, required fields with list-type defaults (like __root__: list[ID] = ['abc', 'efg']) were generated with direct list assignments. Now they correctly use Field(default_factory=lambda: ...) which follows Python best practices for mutable defaults. This changes the structure of generated code for root models and similar patterns with list defaults. (#2958)
Before:
```
class Family(BaseModel):
    __root__: list[ID] = ['abc', 'efg']
```
After:
```
class Family(BaseModel):
    __root__: list[ID] = Field(
        default_factory=lambda: [ID.parse_obj(v) for v in ['abc', 'efg']]
    )
```

What's Changed

Separate pytest-benchmark into dedicated benchmark dependency group by @koxudaxi in #2937
Support ClassVar for Pydantic v2 by @ubaumann in #2920
Add schema version detection and feature flags by @koxudaxi in #2924
Fix MRO ordering for multiple inheritance in GraphQL and JSON Schema/OpenAPI by @koxudaxi in #2941
Add schema_features property to parsers for version detection by @koxudaxi in #2929
Fix $ref handling in request-response mode for readOnly/writeOnly schemas by @koxudaxi in #2942
Ensure codecov upload runs even when coverage check fails by @koxudaxi in #2944
Add FeatureMetadata to schema feature classes for doc generation by @koxudaxi in #2945
Add schema-docs auto-generation with pre-commit and CI by @koxudaxi in #2949
Add comprehensive feature metadata to schema version dataclasses by @koxudaxi in #2946
fix: move UnionMode import outside TYPE_CHECKING for Pydantic runtime… by @phil65 in #2950
Fix IndexError when using --reuse-scope=tree with single file output by @koxudaxi in #2954
Add --use-closed-typed-dict option to control PEP 728 TypedDict generation by @koxudaxi in #2956
Fix RootModel default value not being applied by @koxudaxi in #2960
Fix required list fields ignoring empty default values by @koxudaxi in #2958
Add GenerateConfig lazy import from top-level module by @koxudaxi in #2961
Fix allOf array property merging to preserve child $ref by @koxudaxi in #2962
Fix array RootModel default value handling in parser by @koxudaxi in #2963
Fix bug in handling of graphql empty list defaults by @rpmcginty in #2948

New Contributors

@ubaumann made their first contribution in #2920
@phil65 made their first contribution in #2950

Full Changelog: 0.52.2...0.53.0