Incorrect schema generated for PATCH requests when using Microsoft.AspNetCore.JsonPatch library

[Geetika Paul]

Describe the issue
Incorrect schema generated for PATCH requests when using Microsoft.AspNetCore.JsonPatch library

Steps to reproduce the behavior:

1. Create a PATCH endpoint with request body type as JsonPatchDocument
2. Run the application and open Swagger UI
3. Go to PATCH endpoint
4. The expected schema is
   [
   {
   "op": "string",
   "value": {},
   "path": "string"
   }
   ]
   but generated is
   {
   "operations": [
   {
   "op": "string",
   "value": {},
   "path": "string"
   }
   ]
   }

If we send request with the generated schema the JsonPatch libaray throws the following error: "The JSON patch document was malformed and could not be parsed."

test from jsonpatch library stating "operations" property is unexpected : https://github.com/dotnet/aspnetcore/blob/13a7e9d7223e2041fa4efa0aebf1a7c375a5670f/src/Features/JsonPatch/test/JsonPatchDocumentTest.cs#L129

This issue has been reported in https://michael-mckenna.com/swagger-with-asp-net-core-3-1-json-patch/ and a workaround is suggested.