René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Invalid code generated for nullable discriminated union","articleBody":"**Describe the bug**\r\n\r\nGiven the schema below, using the generated code like:\r\n\r\n```python\r\nfrom test_client.models.demo import Demo\r\nfrom test_client.models.a import A\r\n\r\nDemo(example_union=A()).to_dict()\r\n```\r\n\r\nfails with:\r\n\r\n```\r\nTraceback (most recent call last):\r\n  File \"/Users/eric/Desktop/test/test.py\", line 4, in \u003cmodule\u003e\r\n    Demo(example_union=A()).to_dict()\r\n  File \"/Users/eric/Desktop/test/test_client/models/demo.py\", line 32, in to_dict\r\n    elif isinstance(self.example_union, Union[\"A\", \"B\"]):\r\n         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/Users/eric/.pyenv/versions/3.12.1/lib/python3.12/typing.py\", line 1564, in __instancecheck__\r\n    return self.__subclasscheck__(type(obj))\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/Users/eric/.pyenv/versions/3.12.1/lib/python3.12/typing.py\", line 1568, in __subclasscheck__\r\n    if issubclass(cls, arg):\r\n       ^^^^^^^^^^^^^^^^^^^^\r\nTypeError: issubclass() arg 2 must be a class, a tuple of classes, or a union\r\n```\r\n\r\n**OpenAPI Spec File**\r\n\r\n```yaml\r\nopenapi: 3.0.3\r\ninfo:\r\n  title: Test\r\n  version: 0.0.0\r\n  description: test\r\npaths: {}\r\ncomponents:\r\n  schemas:\r\n    Demo:\r\n      type: object\r\n      properties:\r\n        example_union:\r\n          allOf:\r\n            - $ref: '#/components/schemas/ExampleUnion'\r\n          nullable: true # \u003c-- bug does not happen if this line is removed\r\n    A:\r\n      type: object\r\n      properties:\r\n        type:\r\n          type: string\r\n    B:\r\n      type: object\r\n      properties:\r\n        type:\r\n          type: string\r\n    ExampleUnion:\r\n      oneOf:\r\n      - $ref: '#/components/schemas/A'\r\n      - $ref: '#/components/schemas/B'\r\n      discriminator:\r\n        propertyName: type\r\n        mapping:\r\n          a: '#/components/schemas/A'\r\n          b: '#/components/schemas/B'\r\n```\r\n\r\n\r\n**Desktop**\r\n - OS: macOS 14.3\r\n - Python Version: 3.12.1\r\n - openapi-python-client version: 0.17.2\r\n\r\n**Additional context**\r\n\r\nThe failing generated code is:\r\n\r\n```python\r\nisinstance(self.example_union, Union[\"A\", \"B\"])\r\n```\r\n\r\nUsing `instanceof` on a `Union` with quoted types is not allowed:\r\n\r\n```\r\n\u003e\u003e\u003e class A:\r\n...     pass\r\n...\r\n\u003e\u003e\u003e class B:\r\n...     pass\r\n...\r\n\u003e\u003e\u003e from typing import Union\r\n\u003e\u003e\u003e isinstance(None, Union[A, B])\r\nFalse\r\n\u003e\u003e\u003e isinstance(None, Union[\"A\", \"B\"])\r\nTraceback (most recent call last):\r\n  File \"\u003cstdin\u003e\", line 1, in \u003cmodule\u003e\r\n  File \"/Users/eric/.pyenv/versions/3.12.1/lib/python3.12/typing.py\", line 1564, in __instancecheck__\r\n    return self.__subclasscheck__(type(obj))\r\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\r\n  File \"/Users/eric/.pyenv/versions/3.12.1/lib/python3.12/typing.py\", line 1568, in __subclasscheck__\r\n    if issubclass(cls, arg):\r\n       ^^^^^^^^^^^^^^^^^^^^\r\nTypeError: issubclass() arg 2 must be a class, a tuple of classes, or a union\r\n```","author":{"url":"https://github.com/codebutler","@type":"Person","name":"codebutler"},"datePublished":"2024-02-09T18:53:43.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/958/openapi-python-client/issues/958"}