The GetSchemaTitles functions returns no options when no allOf, anyOf, oneOf children have titles.

[darrelmiller]

See this code:

kiota/src/Kiota.Builder/Extensions/OpenApiSchemaExtensions.cs

Line 34 in b8b3349

else if(schema.AnyOf.Any()) return schema.AnyOf.SelectMany(x => x.GetNonEmptySchemas());

Generation fails with an OpenAPI description like the following,

  '/unionType':
    get:
      responses:
        '200':
          description: A response with two or more distinct types 
          content:
            'application/json':
              schema:
                oneOf:
                - $ref: "#/components/schemas/simpleObject"
                - { type: number }
      x-csharp: Task<GetUnionTypeResponse> GetAsync(...);  

We need to fallback to something like UnionTypeResponse as a classname. When declarationName is empty, the generation fails with an ugly error.

[baywet]

related #835