Describe the bug
When generating msgspec.Struct models from an OpenAPI discriminated union, a variant whose discriminator field is a single-value enum is generated with tag=None.
For example:
class StartedEvent(Struct, tag_field='type', tag=None):
I would expect the generated tag to use the discriminator enum value instead.
To Reproduce
openapi.yaml:
openapi: 3.1.0
info: {title: Repro, version: 0.0.1}
paths: {}
components:
schemas:
Event:
discriminator: {propertyName: type}
oneOf:
- $ref: '#/components/schemas/StartedEvent'
- $ref: '#/components/schemas/StoppedEvent'
StartedEvent:
type: object
properties:
type: {type: string, enum: [started]}
required: [type]
StoppedEvent:
type: object
properties:
type: {type: string, enum: [stopped]}
required: [type]Run:
datamodel-codegen \
--input openapi.yaml \
--input-file-type openapi \
--output-model-type msgspec.Struct \
--output model.py \
--target-python-version 3.10 \
--enum-field-as-literal all \
--use-one-literal-as-default \
--disable-timestamp \
--disable-warnings
Actual generated output:
class StartedEvent(Struct, tag_field='type', tag=None):
pass
class StoppedEvent(Struct, tag_field='type', tag=None):
passExpected generated output:
class StartedEvent(Struct, tag_field='type', tag='started'):
pass
class StoppedEvent(Struct, tag_field='type', tag='stopped'):
passVersion
- OS: Linux
- Python version: 3.10.20
- datamodel-code-generator version: 0.57.0
- msgspec version: 0.21.1
Additional context
--use-one-literal-as-default does not fix this for msgspec.Struct.
This may be related to #2002, but the behavior here is specific to msgspec.Struct tag generation: the class kwarg is written as tag=None instead of the single discriminator enum value.
Describe the bug
When generating
msgspec.Structmodels from an OpenAPI discriminated union, a variant whose discriminator field is a single-valueenumis generated withtag=None.For example:
I would expect the generated tag to use the discriminator enum value instead.
To Reproduce
openapi.yaml:Run:
Actual generated output:
Expected generated output:
Version
Additional context
--use-one-literal-as-defaultdoes not fix this formsgspec.Struct.This may be related to #2002, but the behavior here is specific to
msgspec.Structtag generation: the class kwarg is written astag=Noneinstead of the single discriminator enum value.