Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

JsonSubTypes

Fixed

• Deserialization with an open generic base type (e.g. Base<>) now closes the generic subtype correctly (e.g. Nested1<int> for Base<int>) instead of failing. #177
• Errors and exceptions raised while deserializing a subtype now carry the fully qualified JSON path (e.g. Property2.Value instead of Value), matching stock Newtonsoft.Json error handling. #182

JsonSubTypes.Text.Json

Changed

• The converter caches the resolved IJsonSubtypes converter list per JsonSerializerOptions (frozen on first use) and resolves single-level hierarchies without per-object allocations.
• Deserialization reads the resolved subtype from the already-parsed JsonElement instead of re-reading the raw bytes through a second materialization.
• The discriminator write path streams the payload as UTF-8 (ArrayBufferWriter + Utf8JsonWriter) instead of round-tripping through a UTF-16 string.

[1.0.0-rc.3] - 2026-08-12

JsonSubTypes.Text.Json

Added

• New JsonSubTypesAotConverterAttribute opting a base type into the JsonSubTypes.Text.Json.Aot source generator.

JsonSubTypes.Text.Json.Aot

Added

• New package JsonSubTypes.Text.Json.Aot (1.0.0-rc.1): a Roslyn source generator emitting compiled subtype converters. Routing (property presence, fallback, enums, nested hierarchies, dynamic registration) is compiled, so it works in Native AOT / trimmed binaries without reflection.

[1.0.0-rc.2] - 2026-08-10

Changed

• Rebuilt with Source Link, deterministic builds and .snupkg symbol packages so symbols validate against the published package.

[1.0.0-rc.1] - 2026-08-10

Added

• New package JsonSubTypes.Text.Json bringing polymorphic subtype serialization to System.Text.Json (.NET 8+).
  • Attribute-based and builder-based subtype registration.
  • Discriminator mapping by property presence (KnownSubTypeWithProperty).
  • Fallback subtype support (FallBackSubType).
  • Opt-in cross-assembly subtype resolution (JsonSubTypesTypeResolution.AddAssembly).
  • Comprehensive unit test suite with 129 test cases.

[2.1.0] - 2026-08-10

Added

• Make JsonSubtypesConverter and JsonSubtypesByDiscriminatorValueConverter public and subclassable: custom subtype converters can now be built with a custom discriminator mapping and control over discriminator serialization, instead of being limited to the fluent builder. #138

Fixed

• Deserializing dates now matches stock Newtonsoft deserialization #166 #167

Changed

• Bump Newtonsoft.Json dependency to 13.0.4
• Deterministic builds, Source Link and .snupkg symbol packages

[2.0.1] - 2022-05-09

Fixed

• Add package description with an included README.md

[2.0.0] - 2022-05-09

Changed

• Discriminator property is placed first by default now #46 #149
• Depends on the latest Newtonsoft.Json #131 #148
• Signature of SetFallbackSubtype has been changed to fix a design bug #152 #147

Added

• Allow to stop searching when a match is found #128 #151

Fixed

• Fix a DateTime issue introduced in release 1.8.0 #120 #128

[1.9.0] - 2022-05-09

Added

• Add version of builder methods with generic types for cleaner syntax. #110
• Support (serializing) sub types with generic type parameters when using JsonSubtypesConverterBuilder #135
• Add cache of type’s attributes #119

Fixed

• Newtonsoft.Json dependency version should be lowest supported, not latest available #101
• Multiple type discriminators in JSON silently passes. #100
• Incorrect handling of datetime field in a sub-type #114
• Too many target framework inside the nuget package #48
• Copy MaxDepth when creating internal JObjectReader #137
• Fix deserialization of hierarchy with multiple levels #118

[1.8.0] - 2020-09-24

Added

• Add version of builder methods with generic types for cleaner syntax. #115

Fixed

• Newtonsoft.Json dependency version should be lowest supported, not latest available #101
• Multiple type discriminators in JSON silently passes. #100
• Incorrect handling of datetime field in a sub-type #114

[1.7.0] - 2020-03-28

Added

• Fallback to JSONPath to allow nested field as a deserialization property. #89
• Bump Newtonsoft.Json from 11.0.2 to 12.0.3 #88
• Implements dynamic registration for subtype detection by property presence. #50

Fixed

• JsonSubtypes does not respect naming strategy for discriminator property value #80
• Fix infinite loop when specifying name of abstract base class as discriminator #83
• Serializing base class with discriminator property results in KeyNotFoundException #79

[1.6.0] - 2019-06-25

Added

• Support for multiple discriminators on single type #66
• Support for per inheritance level discriminators #60
• Support specifying a falback sub type if none matched #63
• Provide NuGet package with strong name #75
• Changelog history and documentation arround versionning

[1.5.2] - 2019-01-19

Security

• Arbitrary constructor invocation #56

[1.5.1] - 2018-10-15

Fixed

• Read.me was imported by the nuget install #51

[1.5.0] - 2018-08-27

Added

• Ability to set the discriminator property order to first (see #46)
• Compatibility with JSON.NET 11.0.2 (see #47)

[1.4.0] - 2018-04-18

Added

• Support for both camel case and non camel case parameters #31
• Explicit support for netstandard2.0 #34

Fixed

• Code refactoring to reduce the number of conditional compilation statements #36

[1.3.1] - 2014-04-12

Fixed

• fixed exception that was returned instead of thrown #32

[1.3.0] - 2018-29-01

Added

• De-/Serialization for sub-types without “type” property #13
• Option for avoiding mapping on the Parent #26

Fixed

• Sonar (Coverage) analysis is broken #23

[1.1.3] - 2017-11-15

Fixed

• fixed support of framework net40 #21

[1.1.2] - 2017-11-20

Fixed

• fix #18 : Deserialisation is not thread safe

[1.1.1] - 2017-09-22

Fixed

• fix #11 Nuget packages doesn’t work for .Net Framework projects

[1.1.0] - 2017-09-19

Added

• Parse string enum values #9.

[1.0.0] - 2017-07-23

Initial release !