koxudaxi/datamodel-code-generator 0.54.0 on GitHub

Breaking Changes

Code Generation Changes

Enum member names from oneOf/anyOf const constructs now use title field when provided - Previously, when creating enums from oneOf/anyOf constructs with const values, the title field was incorrectly ignored and enum member names were generated using the pattern {type}_{value} (e.g., integer_200). Now, when a title is specified, it is correctly used as the enum member name (e.g., OK instead of integer_200). Users who have code depending on the previously generated enum member names will need to update their references. (#2975)
Before:
```
class StatusCode(IntEnum):
    integer_200 = 200
    integer_404 = 404
    integer_500 = 500
```
After:
```
class StatusCode(IntEnum):
    OK = 200
    Not_Found = 404
    Server_Error = 500
```
Field names matching Python builtins are now automatically sanitized - When a field name matches a Python builtin type AND the field's type annotation uses that same builtin (e.g., int: int, list: list[str], dict: dict[str, Any]), the field is now renamed with a trailing underscore (e.g., int_) and an alias is added to preserve the original JSON field name. This prevents Python syntax issues and shadowing of builtin types. Previously, such fields were generated as-is (e.g., int: int | None = None), which could cause code that shadows Python builtins. After this change, the same field becomes int_: int | None = Field(None, alias='int'). This affects fields named: int, float, bool, str, bytes, list, dict, set, frozenset, tuple, and other Python builtins when their type annotation uses the matching builtin type. (#2968)
$ref with non-standard metadata fields no longer triggers schema merging - Previously, when a $ref was combined with non-standard fields like markdownDescription, if, then, else, or other extras not in the whitelist, the generator would merge schemas and potentially create duplicate models (e.g., UserWithExtra alongside User). Now, only whitelisted schema-affecting extras (currently just const) trigger merging. This means:
- Fewer merged/duplicate models will be generated
- References are preserved directly instead of being expanded
- Field types may change from inline merged types to direct references
  Example schema:
```
properties:
  user:
    $ref: "#/definitions/User"
    nullable: true
    markdownDescription: "A user object"
```
Before: Could generate a merged UserWithMarkdownDescription model
After: Directly uses User | None reference (#2993)
Enum member names no longer get underscore suffix with --capitalise-enum-members - Previously, enum values like replace, count, index would generate REPLACE_, COUNT_, INDEX_ when using --capitalise-enum-members. Now they correctly generate REPLACE, COUNT, INDEX. The underscore suffix is only added when --use-subclass-enum is also used AND the lowercase name conflicts with builtin type methods. Users relying on the previous naming (e.g., referencing MyEnum.REPLACE_ in code) will need to update to use the new names without trailing underscores. (#2999)
Fields using $ref with inline keywords now include merged metadata - When a schema property uses $ref alongside additional keywords (e.g., const, enum, readOnly, constraints), the generator now correctly merges metadata (description, title, constraints, defaults, readonly/writeOnly) from the referenced schema into the field definition. Previously, this metadata was lost. For example, a field like type: Type may now become type: Type = Field(..., description='Type of this object.', title='type') when the referenced schema includes those attributes. This also affects additionalProperties and OpenAPI parameter schemas. (#2997)

What's Changed

Refactor ruff check+format to use sequential subprocess calls by @koxudaxi in #2967
Fix title ignored when creating enums from merging allOf's or anyOf's objects by @ilovelinux in #2975
Fix aliased imports not applied to base classes and non-matching fields by @koxudaxi in #2981
Fix handling of falsy default values for enums in set-default-enum-member option by @kkinugasa in #2977
Fix use_union_operator with Python builtin type field names by @koxudaxi in #2968
Support $recursiveRef/$dynamicRef in JSON Schema and OpenAPI by @koxudaxi in #2982
Address review feedback for recursive/dynamic ref support by @koxudaxi in #2985
Fix RecursionError in _merge_ref_with_schema for circular $ref by @koxudaxi in #2983
Fix missing Field import with multiple aliases on required fields by @koxudaxi in #2992
Fix patternProperties/propertyNames key constraints lost with field_constraints by @koxudaxi in #2994
Fix type loss when $ref is used with non-standard metadata fields by @koxudaxi in #2993
Fix missing | None for nullable enum literals in TypedDict by @koxudaxi in #2991
Fix exact imports with module/class name collision by @koxudaxi in #2998
Fix extra underscore on enum members like replace with --capitalise-enum-members by @koxudaxi in #2999
Fix merged result in parse_item not passed back to parse_object_fields by @koxudaxi in #2997
Fix codespeed python version by @koxudaxi in #3000
Fix incorrect relative imports with --use-exact-imports and --collapse-root-models by @koxudaxi in #2996

New Contributors

@kkinugasa made their first contribution in #2977

Full Changelog: 0.53.0...0.54.0