I am evaluating ash_graphql 1.8.3 and pretty happy and impressed. but i struggle to get a union as action argument working that includes a “Ash.TypedStruct” member.

given the following “MyUnion” module:

defmodule Todos.MyUnion do
  use Ash.Type.NewType,
    subtype_of: :union,
    constraints: [
      types: [
        member1: [
          type: {:array, :boolean},
          tag: :type,
          tag_value: "member1"
        ],
        member2: [
          type: :string,
          tag: :type,
          tag_value: "member2"
        ],
        # ---- the member3 is causing a compile error
        member3: [
          type: Todos.MyType,
          tag: :type,
          tag_value: "member3"
        ]
      ]
    ]

  use AshGraphql.Type

  def graphql_type(_), do: :my_union
  def graphql_input_type(_), do: :my_union_input
end

Todos.MyType module:

defmodule Todos.MyType do
  use Ash.TypedStruct

  typed_struct do
    field :street, :string, allow_nil?: false
    field :city, :string, allow_nil?: false
    field :state, :string, constraints: [max_length: 2]
    field :zip, :string, constraints: [match: ~r/^\d{5}$/]
  end

  use AshGraphql.Type

  def graphql_type(_), do: :my_type
  def graphql_input_type(_), do: :my_type_input
end

the Todos.Item resource action:

defmodule Todos.Item do
...
    action :union_test do
      argument :union_arg, Todos.MyUnion, allow_nil?: false
      run fn input, context ->
        :ok
      end
    end
...
end

i get the following error on compilation:

** (Absinthe.Schema.Error) Compilation failed:
---------------------------------------
## Locations
/workspace/apps/.../deps/ash_graphql/lib/ash_graphql.ex:313

In field Value, :my_type is not defined in your schema.

Types must exist if referenced.
---------------------------------------
## Locations
/workspace/apps/.../deps/ash_graphql/lib/ash_graphql.ex:313

In argument Member3, :my_type_input is not defined in your schema.

Types must exist if referenced.


    (absinthe 1.7.10) lib/absinthe/schema.ex:414: Absinthe.Schema.__after_compile__/2
    (stdlib 6.2.2) lists.erl:2146: :lists.foldl/3
    (elixir 1.18.4) lib/kernel/parallel_compiler.ex:423: anonymous fn/5 in Kernel.ParallelCompiler.spawn_workers/8

it seems that the union-member type’s are not being registered in the absinthe. i tried to dig into the ash_graphql/absinthe source, but was not able to pin-point where this is happening.

i am not sure if this is a bug or i did something wrong in the code above.

if i comment out “member3”, the union as argument works as expected:

        #member3: [
        #  type: Todos.MyType,
        #  tag: :type,
        #  tag_value: "member3"
        #]

if i use the Todos.MyType, instead of Todos.MyUnion as argument, it also works as expected:

defmodule Hamazon.Todos.Item do
...
    action :union_test do
      argument :union_arg, Todos.MyType, allow_nil?: false
      run fn input, context ->
        :ok
      end
    end
...
end

any help would be really appreciated.