Missing oneOf sections for polymorphic schema

[wtrocki]

Using swagger core with java structures that have multiple polymorphism use cases.

Current state

Swagger core always require to specify oneOf when discriminator mapping is present

@Schema(
    discriminatorProperty = "type",
    discriminatorMapping = {
         {
            @DiscriminatorMapping(
                value = "Test",
                schema = MyClass1.class)
          },
    }
    oneOf = {
      MyClass1.class
    })

Expected behaviour

Swagger core discovers and provides oneOf values for schemas (especially when discriminator mapping is present)

@Schema(
    discriminatorProperty = "type",
    discriminatorMapping = {
         {
            @DiscriminatorMapping(
                value = "Test",
                schema = MyClass1.class)
          },
    })

[wtrocki]

OpenAPI Spec explaining discriminator and oneOf requirement: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.2.md#discriminator-object

[jochenberger]

See also #3411