Revert media type change for Newtonsoft JsonPatch package

[halter73]

This reverts the media type change from #62988 from the Newtonsoft.Json-based Microsoft.AspNetCore.JsonPatch package because in addition to enhancing the OpenAPI metadata, it had the unintended consequence of requiring all JSON Patch requests use exactly the normative Content-Type: application/json-patch+json header. This caused requests using the previously allowed Content-Type: application/json header to fail with a 415 Unsupported Media type response. This regression was reported by multiple people.

This leaves the Microsoft.AspNetCore.JsonPatch.SystemTextJson package unchanged, since it was a NuGet package introduce for .NET 10 and therefore has no regression making us more comfortable with the stricter behavior.

An additional benefit of reverting the Newtonsoft.Json-based Microsoft.AspNetCore.JsonPatch changes is that the package should once again become usable from Blazor WASM since we're removing the newly-added <Reference Include="Microsoft.AspNetCore.Http.Abstractions" Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp'" />. The inability to reference the package in a Blazor WASM app was also a regression in .NET 10 reported by multiple people.

This adds new tests to verify PatchContentTypes_AreHandledAsExpected. The OpenApi tests were also updated to verify that the request media type inferred from the JsonPatchDocument parameter can be completely overridden.

Fixes #65325
Fixes #64330

I plan to backport this to .NET 10 for servicing once this is approved.

[Copilot]

Pull request overview

Reverts the stricter AcceptsMetadata/endpoint metadata behavior added for Microsoft.AspNetCore.JsonPatch (Newtonsoft.Json) so PATCH requests can again use Content-Type: application/json, while keeping Microsoft.AspNetCore.JsonPatch.SystemTextJson’s stricter behavior unchanged.

Changes:

• Remove IEndpointParameterMetadataProvider/AcceptsMetadata population from Newtonsoft JsonPatchDocument types and drop the extra framework reference that made the package unusable for Blazor WASM.
• Add end-to-end tests validating which Content-Type values are accepted for both Newtonsoft and System.Text.Json JsonPatch packages.
• Update OpenAPI tests to verify Accepts(...)/[Consumes] can fully override the inferred JsonPatch request media type.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/OpenApi/test/Microsoft.AspNetCore.OpenApi.Tests/Services/OpenApiDocumentService/OpenApiDocumentServiceTests.RequestBody.cs	Tightens assertions to ensure inferred JsonPatch media types are fully overridden by explicit Accepts/Consumes.
src/Features/JsonPatch/test/Microsoft.AspNetCore.JsonPatch.Tests.csproj	Adds required ASP.NET Core references for new end-to-end tests on .NET Core targets.
src/Features/JsonPatch/test/JsonPatchContentTypeEndToEndTest.cs	New end-to-end coverage for accepted/rejected PATCH content types (Newtonsoft package).
src/Features/JsonPatch/src/Microsoft.AspNetCore.JsonPatch.csproj	Removes framework reference that was introduced for endpoint metadata support (improves Blazor WASM compatibility).
src/Features/JsonPatch/src/JsonPatchDocumentOfT.cs	Removes endpoint-parameter metadata provider implementation that enforced application/json-patch+json.
src/Features/JsonPatch/src/JsonPatchDocument.cs	Removes endpoint-parameter metadata provider implementation that enforced application/json-patch+json.
src/Features/JsonPatch.SystemTextJson/test/Microsoft.AspNetCore.JsonPatch.SystemTextJson.Tests.csproj	Adds required references for new end-to-end tests.
src/Features/JsonPatch.SystemTextJson/test/JsonPatchContentTypeEndToEndTest.cs	New end-to-end coverage confirming stricter content-type behavior remains for SystemTextJson package.

[BrennanConroy]

I assume some sort of breaking change announcement is going to be made for this area?

Is there going to be a follow up discussion for blazor-wasm getting a non-newtonsoft json version?

[halter73]

I assume some sort of breaking change announcement is going to be made for this area?

Maybe. I'm not sure how necessary it is given that we're reverting to the pre-.NET 10 behavior. It might just create more confusion. #65325 and #64330 should serve as notice of the unintentional breaking change until the next patch.

Is there going to be a follow up discussion for blazor-wasm getting a non-newtonsoft json version?

As far as I know, you simply cannot reference Microsoft.AspNetCore.Http.Abstractions from blazor-wasm either directly or indirectly (you wouldn't want Blazor WASM code referencing HttpContext after all). We may be able to #ifdef and multitarget for net11.0-browser though. I didn't want to do that for the patch since we had multiple reasons to revert the changes in the Newtonsoft JsonPatch package, but it could make sense to do that for the STJ package going forward in .NET 11. Assuming that's possible. Otherwise, it might be better to rip off the band aid and remove the Microsoft.AspNetCore.Http.Abstractions reference from the STJ package as well. I'm curious if @javiercn has any thoughts on this scenario.