Developers should have a more consistent experience when using System.Text.Json

[eiriktsarpalis]

User story tracking known semantic divergences/reliability bugs in System.Text.Json that we consider to be impactful and should be fixed in .NET 8.

.NET 8 plan

Property visibility and attribute handling

• System.Text.Json should handle attributes in virtual or shadowed properties consistently #73255
• Serialization of properties from inherited interfaces vs abstract base classes  #41749

General

• [System.Text.Json] Allow TimeOnly as Dictionary key #77566
• .NET 7 Preview 7 - Polymorphic Deserialization ignores PropertyNameCaseInsensitive setting #75269
• [JsonSerializer] Relax restrictions on ctor param type to immutable property type matching where reasonable #44428
• Fix JSON issue (InvalidCastException) with ctor nullable enum ctor params having default values #68647

Addressed in .NET 7

Click to view

JsonSerializer issues

Enhancements

• JsonObject does not respect JsonIgnoreCondition.WhenWritingNull #54184
• Remove use of pool and buffer copy in Deserialize(ref Utf8JsonReader reader, ...) #70902
• Consider caching Utf8JsonWriter and PooledByteBufferWriter on a thread static in JsonSerializer.Serialize #69889

Bugs

• System.Text.Json.JsonSerializer does not work with Dictionary<string, object> #67588
• ArgumentNullException in System.Text.Json.Serialization.Metadata.JsonTypeInfo #58690
• JsonSerializer throw an InvalidCastException when serializing an array of item with a custom converter #46522
• System.Text.Json: JsonStringEnumConverter ignores its JsonNamingPolicy during deserialization. #31619

Error message improvements

• STJ failing ungracefully when attempting to serialize attributes #58947

Source generation Issues

Enhancements

• System.Text.Json source generator crashes when processing unresolved symbols #68072
• Use of JsonSerializerContext Can Cause CS1591 #61379

Bugs

• NullableConverter does not flow serialization state #65522
• Sync stream serialization not handling IAsyncEnumerable correctly #66687
• JSON source gen doesn't detect [JsonNumberHandling] when applied to POCO #58638 (moved to .NET 8)

Misc Reliability Enhancements

• System.Text.Json: Using JsonStringEnumConverter, after changing CurrentCulture to "sv-SE", enums with unknown negative values serialize strangely, and cannot be deserialized. #68600
• Test failed at double initialization assert in System.Text.Json.Serialization.Metadata.JsonTypeInfo.InitializePropCache() #60962
• System.Text.Json ObjectConverter does not handle reference metadata correctly on deserialization #67171
• [System.Text.Json] DeserializeAsyncEnumerable is delayed emitting objects when writing asynchronously to stream #70107
• Examine JsonSerializer behavior for ref structs & pointers #34779
• ArgumentNullException in System.Text.Json.Serialization.Metadata.JsonTypeInfo #58690

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

Issue Details

---

User story tracking known semantic divergences/reliability bugs in System.Text.Json that we consider to be impactful and should be fixed in .NET 7.

Contract Model Consistency Issues

• Serialization of properties from inherited interfaces vs abstract base classes  #41749
• JsonIgnore attribute is not inherited in overridden properties #50078
• The 'new' modifier doesn't always work with [JsonIgnore] #59675
• [JsonSerializer] Relax restrictions on ctor param type to immutable property type matching where reasonable #44428
• JsonObject does not respect JsonIgnoreCondition.WhenWritingNull #54184
• Default value for optional ctor params should be used when matching prop is ignored #60082
• JsonPropertyName inheritance perserve the parent member #51165
• System.Text.Json custom converter for Dictionary<string, object> collides with JsonExtensionData #60560
• JsonConverter inconsistency when deserializing into property without public getter #56212
• Internal json converters cannot function independently of their original options #50205

High-Impact Bugs

• NullReferenceException when composing a custom converter with a default converter #57280
• STJ failing ungracefully when attempting to serialize attributes #58947
• System.Text.Json constructor deserializing with covariant return type read-only properties sets values to null #56999
• JsonSerializer throw an InvalidCastException when serializing an array of item with a custom converter #46522
• System.Text.Json not properly disposing enumerators on exceptions #50851
• Examine JsonSerializer behavior for ref structs & pointers #34779
• Guard against invalid TypeToConvert args to read methods of object and collection converter #36605
• System.Text.Json does not support constructors with byref parameters. #46088
• System.Text.Json: JsonStringEnumConverter ignores its JsonNamingPolicy during deserialization. #31619
• JsonStringEnumConverter ignores 'allowIntegerValues' when deserializing quoted numeric values #58247
• Discrepancies in Utf8JsonReader between single- and multi-segment modes for invalid JSON #30706
• System.Text.Json object cycle error message could be better #38786

Author:	eiriktsarpalis
Assignees:	eiriktsarpalis
Labels:	area-System.Text.Json, User Story, Priority:2, Cost:L, Team:Libraries
Milestone:	7.0.0