Composed +discriminator models, use dynamic base classes

[spacether]

OpenAPITools/openapi-generator#6797
This above different PR allows composed schemas to return instances of self composed schema None, or int. We enable mixed type returns in composed schemas in python. But it's painful because our endpoint input arguments for ComposedSchema can be None, int, or ComposedSchema. That requires us to traverse ComposedSchema on the client side when we send a ComposedSchema with None or int input, which takes O(n). An easier implementation which would eliminate that O(n) traversal would be to have all instances of ComposedSchema be type ComposedSchema. That requires wrapping all possible results in that type including None, int, Cat etc. in ComposedSchema.

Use Cases That this will address

Dynamic class inheritance it will allow us to generally solve these use cases:

• Discriminator inheritance (2 classes, Animal + chosen class)
• OneOf (2 classes, outer and oneof)
• AnyOf (n classes)
• AllOf + OneOf (2 classes)
• AllOf + AnyOf (n classes)
• AllOf (outer + n allof classes)
• composed in composed in.. (n classes)

@sebastien-rosset do you know of any other use cases that should be covered here?

This could be a useful pattern in dynamic languages like python, Ruby etc.
With this pattern, when creating an Animal, the returned instance (Cat or Dog) will always be an instance of and a subclass of Animal.

Examples in our file

Discriminator

• Animal Cat + Dog mock discriminator

OneOf Example

• Panther

ModelSImple example (inherit from Class that is primitive type with validations)

• IntModel

Inherit from primitive types

• None, True, False (classes that can't be used as base classes in python)
  • We can get those working by returning them as Enum class instances
• float, see 3.14 input to ComposedSchema
• string enum, see 'red' input to ComposedSchema
• list, see [] input to ComposedSchema
• array model, see [0] input to ComposedSchema

[spacether]

Closing this because incorporating this concept is moving forward in OpenAPITools/openapi-generator#8325