Property with type array in Schema mentioned in allOf not properly casted to struct

[dkln]

First of all: thanks for the hard work on this Hex package. I love it ❤️

It seems there is a small bug when casting an Object mentioned in allOf that contains a property that is an array and mentions another Schema with items.

An example. Given the following schemas:

defmodule Hobby do
  require OpenApiSpex

  alias OpenApiSpex.Schema

  OpenApiSpex.schema(%{
    type: :object,
    properties: %{
      name: %Schema{type: :string, minLength: 1, maxLength: 30}
    }
  })
end

defmodule Person do
  require OpenApiSpex

  alias OpenApiSpex.Schema

  OpenApiSpex.schema(%{
    type: :object,
    properties: %{
      hobbies: %Schema{type: :array, items: Hobby}
    }
  })
end

defmodule Employee do
  require OpenApiSpex

  alias OpenApiSpex.Schema

  OpenApiSpex.schema(%{
    type: :object,
    allOf: [
      Person,
      %Schema{
        type: :object,
        properties: %{
          employee_number: %Schema{type: :string}
        }
      }
    ]
  })
end

When using the Person schema, the casting of hobbies works as expected:

  params = %{hobbies: [%{name: "Programming"}, %{name: "Walking"}]}

  OpenApiSpex.Cast.cast("Person", params, specs)

  %Person{
    hobbies: [%Hobby{name: "Programming"}, %Hobby{name: "Walking"}]
  }

However, when using the Employee schema, the casting of hobbies doesn't work as expected (notice that hobbies now contain a list of maps instead of Hobby structs):

  params = %{hobbies: [%{name: "Programming"}, %{name: "Walking"}], employee_number: "123"}

  OpenApiSpex.Cast.cast("Employee", params, specs)

  %Employee{
    hobbies: [%{name: "Programming"}, %{name: "Walking"}],
    employee_number: "123"
  }

But, if I would change the Employee schema to:

defmodule Employee do
  require OpenApiSpex

  OpenApiSpex.schema(%{
    type: :object,
    allOf: [
      Person,
      %Schema{
        type: :object,
        properties: %{
          employee_number: %Schema{type: :string},
          hobbies: %Schema{type: :array, items: Hobby}
        }
      }
    ]
  })
end

It works:

params = %{hobbies: [%{name: "Programming"}, %{name: "Walking"}], employee_number: "123"}

OpenApiSpex.Cast.cast("Employee", params, specs)

%Employee{
  hobbies: [%Hobby{name: "Programming"}, %Hobby{name: "Walking"}],
  employee_number: "123"
}

So it seems that using allOf doesn't comply to the mentioned items schema. Hope these examples clarify the problem a bit. If you need any help or more information, please let me know! I am happy to help you out.