add concrete schema for discriminated types into 'oneOf' for base type

[EvgeniyZ]

fix for #3166

Details on the issue fix or feature implementation

I am not happy how it looks like in Swagger UI, I open for any suggestions

here's how looks Animal class with subtypes. Having refs to himself can easily lead to such unpleasant view

BaseType with SubSubType link

[martincostello]

The tests seem quite broken - it looks like they've got into a cycle somewhere.

[EvgeniyZ]

StackOverflow exception is caused somewhere inside NJsonSchema.JsonSchema, here's truncated exception

NSwag command line tool for .NET Core Net80, toolchain v14.2.0.0 (NJsonSchema v11.1.0.0 (Newtonsoft.Json v13.0.0.0))
Visit http://NSwag.org for more information.
NSwag bin directory: C:\Users\Evgenii\.nuget\packages\nswag.msbuild\14.2.0\tools\Net80
Swagger JSON/YAML successfully written to E:\development\swashbuckle.aspnetcore\test\WebSites\NswagClientExample\swagger_net9.0.json
dotnet "C:\Users\Evgenii\.nuget\packages\nswag.msbuild\14.2.0\buildTransitive\../tools/Net90/dotnet-nswag.dll" openapi2csclient /input:swagger_net9.0.json /namespace:NSwagClient /output:NSwagClient/Client.cs
NSwag command line tool for .NET Core Net90, toolchain v14.2.0.0 (NJsonSchema v11.1.0.0 (Newtonsoft.Json v13.0.0.0))
Visit http://NSwag.org for more information.
NSwag bin directory: C:\Users\Evgenii\.nuget\packages\nswag.msbuild\14.2.0\tools\Net90
Stack overflow.
   at System.Collections.Generic.List`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].set_Capacity(Int32)
   at System.Collections.Generic.List`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].AddWithResize(System.__Canon)
   at NJsonSchema.JsonSchema.GetActualSchemaReferences(System.Collections.Generic.List`1<NJsonSchema.JsonSchema>)
   at NJsonSchema.JsonSchema.GetActualSchema(System.Collections.Generic.List`1<NJsonSchema.JsonSchema>)
   at NJsonSchema.JsonSchema.get_ActualSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Collections.ObjectModel.ObservableCollection`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at NJsonSchema.JsonSchema.get_ActualTypeSchema()
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema.IsNullable(NJsonSchema.SchemaType)
   at NJsonSchema.JsonSchema+<>c.<get_ActualTypeSchema>b__255_2(NJsonSchema.JsonSchema)
   at NJsonSchema.ObservableCollectionExtensions.FirstOrDefault[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, ...
   ...

I assume it crashes while trying to generate C# client via NSwag, in the NSwagClientExample.csproj

  <Target Name="NSwag" AfterTargets="SwaggerToFile">
    <Exec Command="$(_NSwagTool) openapi2csclient /input:swagger_$(TargetFramework).json /namespace:NSwagClient /output:NSwagClient/Client.cs" />
  </Target>

however, I am not able to trace where to find source code for NJsonSchema.JsonSchema.GetActualSchemaReferences method call (or any of the stacktrace above)

@martincostello I appreciate any tips if you have any

[martincostello]

Looks like its gotten in a self-referential loop (e.g. type A has a property of type A in it) and causing a stack overflow in NSwag. Maybe look at the code there?