System.Text.Json work planned for .NET 8

[layomia]

This issue captures the planned work for .NET 8. This list is expected to change throughout the release cycle according to ongoing planning and discussions, with possible additions and subtractions to the scope.

Summary

For .NET 8 we are prioritizing System.Text.Json work according to the following high-level themes:

1. Developers should be able to use System.Text.Json in NativeAOT seamlessly
2. Source generator improvements: improve performance, close functionality gaps with reflection-based implementation, fixing known bugs.
3. Reliability: developers should have a consistent experience when using System.Text.Json; minimize the number of high-impact bugs in the codebase.
4. Extend contract customization capabilities: provide more extensibility points to help users achieve more
5. Extend custom converter capabiliies: provide more capability for users to directly control reading and writing

Planned for .NET 8

• Developers should be able to use System.Text.Json in Native AOT seamlessly #79122
• System.Text.Json Source generator improvements for .NET 8.0 #77019
• Planned System.Text.Json contract customization improvements #71967
• Performance (Enhancements, new perf-focused APIs)
  • Add an analyzer that warns on single-use JsonSerializerOptions instances #65396
  • Implement a heuristic for using fast-path serialization in streaming JsonSerializer methods. #78646
  • [API Proposal]: Add ReadOnlySequence overload for WriteRawValue #68223
  • [API Proposal]: Add a JsonEncodedText.Value property #69716
• Misc (New APIs etc.)
  • Add support for MissingMemberHandling to System.Text.Json #37483
  • [API Proposal]: Add new overloads to ReadFromJsonAsync method in HttpContentJsonExtensions #72103
  • Provide a public api to "lock" a JsonSerializerOptions #54482
  • Add snake_case support for System.Text.Json #782

Not Planned for .NET 8

• Developers should have a more consistent experience when using System.Text.Json #63918
• System.Text.Json converter infrastructure improvements for .NET 8 #77018
• Add JsonElement.ValueSpan #77666

Work done in previous releases

• .NET 7
• .NET 6
• .NET 5

[stefan-schweiger]

Just to clarify, #31068 is not going to happen for .NET 8? The issue is currently tagged for 8.0.0 milestone

[layomia]

The issue is currently tagged for 8.0.0 milestone

@stefan-schweiger the issue is labeled as "future" (Did you mean to link to that issue?)

The latest thought is that the spec is not finished (the latest Internet-Draft appears to be expired) and we should wait for that to settle first.

[gregsdennis]

Hello. Just making myself available for support for JSON Schema and JSON Path. I'm co-author on both specs, and I support both in my json-everything suite of libraries (backed by STJ).

JSON Schema is on a path toward a stable spec (i.e. one that doesn't have draft in the version), and JSON Path is nearing completion with the features in place and only language to tidy up.

[eiriktsarpalis]

Closing as completed. The outstanding issue is an analyzer that will be implemented after RC is done.