allow multiple versions of the schema

tests/test_schema_compat_pydantic_v2.py

@@ -1,4 +1,5 @@
 import pytest
+from dirty_equals import IsOneOf
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
 from inline_snapshot import snapshot
@@ -63,7 +64,9 @@ def test_openapi_schema(client: TestClient):
                 }
             },
             "components": {
-                "schemas": {
+                "schemas": IsOneOf(
+                    # Newer Pydantic: no top-level OtherRole
+                    {
                         "PlatformRole": {
                             "type": "string",
                             "enum": ["admin", "user"],
@@ -84,7 +87,35 @@ def test_openapi_schema(client: TestClient):
                             "required": ["username", "role"],
                             "title": "User",
                         },
-                }
+                    },
+                    # Older Pydantic: adds a top-level OtherRole schema
+                    {
+                        "OtherRole": {
+                            "enum": [],
+                            "title": "OtherRole",
+                        },
+                        "PlatformRole": {
+                            "type": "string",
+                            "enum": ["admin", "user"],
+                            "title": "PlatformRole",
+                        },
+                        "User": {
+                            "properties": {
+                                "username": {"type": "string", "title": "Username"},
+                                "role": {
+                                    "anyOf": [
+                                        {"$ref": "#/components/schemas/PlatformRole"},
+                                        {"enum": [], "title": "OtherRole"},
+                                    ],
+                                    "title": "Role",
+                                },
+                            },
+                            "type": "object",
+                            "required": ["username", "role"],
+                            "title": "User",
+                        },
+                    },
+                )
             },
         }
     )

tests/test_union_body_discriminator.py

@@ -1,5 +1,6 @@
 from typing import Annotated, Any, Literal
 
+from dirty_equals import IsOneOf
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
 from inline_snapshot import snapshot
@@ -88,11 +89,19 @@ def test_discriminator_pydantic_v2() -> None:
                                 "description": "Successful Response",
                                 "content": {
                                     "application/json": {
-                                        "schema": {
+                                        "schema": IsOneOf(
+                                            # Pydantic < 2.11: no additionalProperties
+                                            {
+                                                "type": "object",
+                                                "title": "Response Save Union Body Discriminator Items  Post",
+                                            },
+                                            # Pydantic >= 2.11: has additionalProperties
+                                            {
                                                 "type": "object",
                                                 "additionalProperties": True,
                                                 "title": "Response Save Union Body Discriminator Items  Post",
-                                        }
+                                            },
+                                        )
                                     }
                                 },
                             },