JsonSerializer support for JsonDocument types in source generation mode

[layomia]

JsonSerializer supports (de)serialization of JsonDocument instances. We should add the same support in source-generation mode by exposing the JsonDocumentConverter via a new JsonMetadataServices API.

[ghost]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

Issue Details

---

JsonSerializer supports (de)serialization of JsonDocument instances. We should add the same support in source-generation mode by exposing the JsonDocumentConverter via a new JsonMetadataServices API.

Author:	layomia
Assignees:	-
Labels:	area-System.Text.Json, up-for-grabs
Milestone:	7.0.0

[strobelt]

I can do this!

[strobelt]

I created PR #60236 to fix this. Let me know if I did it right and if there are any improvements I can do!

[eiriktsarpalis]

Does this need API review before we mark up-for-grabs?

[layomia]

Yes the following API needs to be reviewed and approved before we can merge #60236. My apologies @strobelt.

namespace System.Text.Json.Serialization.Metadata
{
    public static partial class JsonMetadataServices
    {
        public JsonConverter<JsonElement> JsonElementConverter { get; }
+       public JsonConverter<JsonDocument> JsonDocumentConverter { get; }
    }
}

[strobelt]

No problem, @layomia!
Just to be clear: should I make any corrections to the PR I created? Or will there be some workk before we create any code for this? I saw the ocmment you added tomy PR and donn't know if I should keep working on it or abandon it.

Thanks for the help!

[eiriktsarpalis]

I think we can use your existing PR @strobelt. We can look at getting the API approved concurrently.

[terrajobst]

Video

• Looks good as proposed

namespace System.Text.Json.Serialization.Metadata
{
    public static partial class JsonMetadataServices
    {
        // Existing
        // public JsonConverter<JsonElement> JsonElementConverter { get; }
        public JsonConverter<JsonDocument> JsonDocumentConverter { get; }
    }
}