Add support for STJ-native C# code gen

[schnerring]

I took another crack at adding the missing System.Text.Json polymorphic serialization features to NSwag's C# client generator (previous PR: #1595).

As per your suggestion I added a C# client generator setting named JsonPolymorphicSerializationStyle that defaults to NSwag (old behavior). Setting it to SystemTextJson will opt into the new behavior:

• Generate JsonPolymorphic and JsonDerivedType attributes
• Don't generate JsonInheritanceConverter and JsonInheritanceAttribute classes

I also added a corresponding (WIP) PR in the NSwag repo that might be missing a couple of things: https://github.com/RicoSuter/NSwag/pull/4782/files

[brrusino]

@schnerring @RicoSuter What's the latest status of this PR?

[schnerring]

@RicoSuter Anything else? It's good to go from my side.

[ryanheath]

@schnerring Would you mind adding a setting to support JsonUnknownDerivedTypeHandling ?

I could do the work if you want me to.

// Ryan

[NikolayTzonev]

@schnerring @RicoSuter What's the latest status of this PR? It is related to issue RicoSuter/NSwag#4375 which is critical because can lead to denial of service on public APIs

[ryanheath]

@schnerring @RicoSuter What's the latest status of this PR? It is related to issue #4375 which is critical because can lead to denial of service on public APIs

Which issue #4375 ?

[NikolayTzonev]

Sorry about that. This issue - RicoSuter/NSwag#4375

[ryanheath]

Yep in christianhelle/refitter/#462 we worked around it using the STJ-native.

[Jozzle]

@schnerring @RicoSuter What's the latest status of this PR? It is related to issue RicoSuter/NSwag#4375 which is critical because can lead to denial of service on public APIs

We're experiencing the same, stackoverflow exceptions on incorrect/missing type discriminator. Any reason why this PR is open for so long?

[RicoSuter]

Thanks for the PR.

Regarding the stackoverflow, I could not really repro this:
22d33c9#diff-181052195a641873f0edadea91a8d21aa00fbd92982bc42bd24431593e9cd04b

[RicoSuter]

Should we make this the new default or is something missing?