Simplify-oneof-anyof OpenAPI generator bug

generator-config.yaml

generatorName: python
inputSpec: bug-repro/openapi.json
outputDir: bug-repro/python
generateSourceCodeOnly: true
globalProperties:
  modelDocs: false
  apiDocs: false
  modelTests: false
  apiTests: false

openapi.json

{
  "openapi": "3.1.0",
  "info": {
    "title": "simplify-oneof-anyof bug repro",
    "version": "0.1.0"
  },
  "paths": {
    "/items/{item_id}": {
      "put": {
        "operationId": "update_item",
        "summary": "Update Item",
        "parameters": [
          {
            "in": "path",
            "name": "item_id",
            "required": true,
            "schema": {"title": "Item Id", "type": "integer"}
          },
          {
            "in": "query",
            "name": "q",
            "required": false,
            "schema": {
              "title": "Q",
              "anyOf": [{"type": "string"}, {"type": "null"}
              ]
            }
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {"schema": {"$ref": "#/components/schemas/Item"}}
          }
        },
        "responses": {
          "200": {
            "description": "Successful Response",
            "content": {
              "application/json": {"schema": {"$ref": "#/components/schemas/UpdateResponse"}}
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "Item": {
        "title": "Item",
        "type": "object",
        "properties": {
          "is_offer": {
            "title": "Is Offer",
            "anyOf": [{"type": "boolean"}, {"type": "null"}]
          },
          "my_enum": {"anyOf": [{"$ref": "#/components/schemas/MyEnum"}, {"type": "null"}]},
          "name": {"title": "Name", "type": "string"}
        },
        "required": ["name"]
      },
      "MyEnum": {
        "title": "MyEnum",
        "type": "string",
        "enum": ["value-1", "value-2"]
      },
      "UpdateResponse": {
        "properties": {
          "id": {"title": "Item Id", "type": "integer"},
          "name": {"title": "Item Name", "type": "string"}
        },
        "required": ["name", "id"],
        "title": "UpdateResponse",
        "type": "object"
      }
    }
  }
}

SIMPLIFY_ONEOF_ANYOF-BUG.md

Setup

Download the files in this gist to a folder called bug-repro.

If you wish to use openapi-generator repository, place bug-repro under the root of the repository.

Expected behavior (v7.2.0)

The Item model should have the following fields defined like so:

class Item(BaseModel):
    is_offer: Optional[StrictBool] = None
    my_enum: Optional[MyEnum] = None
    ...

Actual behavior (v7.3.0, v7.4.0)

OpenAPI normalizer SIMPLIFY_ONEOF_ANYOF does not work (at least for Python).

New models are introduced: ItemMyEnum, IsOffer and Q.

Item's definition looks like:

class Item(BaseModel):
    is_offer: Optional[IsOffer] = None
    my_enum: Optional[ItemMyEnum] = None
    ...

It makes usage very cumbersome:

Item(name='foo',
     my_enum=ItemMyEnum(MyEnum.VALUE_MINUS_1),
     is_offer=IsOffer(True))

Run in openapi-generator repository

From the repository root run:

./run-in-docker.sh generate -c bug-repro/generator-config.yaml

Run in a released docker

From the parent folder of bug-repro run:

OPENAPI_GENERATOR_VERSION=v7.2.0

docker run --rm -w /gen \
  -v ${PWD}:/gen \
  -u "$(id -u):$(id -g)" \
  openapitools/openapi-generator-cli:${OPENAPI_GENERATOR_VERSION} generate \
  -c bug-repro/generator-config.yaml