OneOf schema issues with C# code generation

Description

OneOf schema issues with C# code generation

Please see attached Issue.png

The one on the left (1) is the “broken” one that won’t compile and the one to the right (2) is my “hotfix” to get this class to compile. However, I don’t actually know what model to use for the AppliesTo property and just randomly picked the AppliesToOffer class. In this scenario, if the server is returning AppliesToOfferProduct or AppliesToOfferProductSegment I will not be able to use those additional properties that those models have as my generated client code is unaware of those extra properties. If I pick the AppliesToOfferProductSegment, I will get deserialization errors if any mandatory properties in this model are not returned by the server e.g if the server response is the AppliesToOffer base class.

Swagger-codegen version

3.x

Swagger declaration file content or url

Command line used for generation

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

ExampleAPI.docx

Start with the attached ExampleAPI.docx and IssueCsharp image, then reproduce the problem using Swagger Codegen 3.x with the C# generator. Compare the generated OneOf models for AppliesToOffer, AppliesToOfferProduct, and AppliesToOfferProductSegment; done means the generated client compiles and handles each server response without losing variant properties or causing deserialization errors.