How to extend the payload output macro in absinthe_relay 1.5?

Questions / Help
,
1

Since I migrated from absinthe_relay version 1.4 to 1.5, my code does not compile anymore.

Indeed, I was using a custom macro to extend the payload output/1 macro:

defmodule MyApp.Schema.Notation do
  @moduledoc false

  defmacro mutation({:output, _, _}, do: block) do
    do_output(__CALLER__, block)
  end

  defmacro mutation({:output, _, _}) do
    do_output(__CALLER__, nil)
  end

  defp do_output(_env, block) do
    record_output(block)
  end

  defp record_output(block) do
    body = mutation_output_body()

    quote do
      output do
        unquote(body)
        unquote(block)
      end
    end
  end

  # success and error fields are automatically added
  defp mutation_output_body do
    quote do
      @desc "Indicates if the command succeeded."
      field(:success, non_null(:boolean))
      @desc "Error details."
      field(:error, :error)
    end
  end
end

The custom macro was used this way to add the 2 fields :success and :error on my mutations outputs:

payload field(:register_user) do
  input do
    field(:username, non_null(:string))
    field(:display_name, non_null(:string))
    field(:password, non_null(:string))
    field(:role, non_null(:user_role))
    field(:blocked, non_null(:boolean))
  end

  mutation output do
    field(:user, :user)
  end

  resolve(&Accounts.RegisterUser.resolve/3)
end

payload field(:change_user_username) do
  input do
    field(:user_id, non_null(:id))
    field(:username, non_null(:string))
  end

  mutation(output)

  middleware(Absinthe.Relay.Node.ParseIDs, user_id: :user)
  resolve(&Accounts.ChangeUserUsername.resolve/3)
end

Since absinthe_relay 1.5, output/1 was replaced by output/2 and my code does not compile anymore:

$ mix compile 
Compiling 6 files (.ex)

== Compilation error in file lib/myapp_web/schema/accounts.ex ==
** (CompileError) lib/myapp_web/schema/accounts.ex:28: undefined function output/1
    expanding macro: MyAppWeb.Schema.Notation.mutation/2
    lib/myapp_web/schema/accounts.ex:28: MyAppWeb.Schema.Accounts (module)
    expanding macro: Absinthe.Schema.Notation.field/3
    lib/myapp_web/schema/accounts.ex:12: MyAppWeb.Schema.Accounts (module)
    expanding macro: Absinthe.Relay.Mutation.Notation.Modern.payload/2
    lib/myapp_web/schema/accounts.ex:12: MyAppWeb.Schema.Accounts (module)
    expanding macro: Absinthe.Schema.Notation.object/2
    lib/myapp_web/schema/accounts.ex:10: MyAppWeb.Schema.Accounts (module)
    (elixir 1.10.4) lib/kernel/parallel_compiler.ex:304: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/7

I understand the compilation error: my custom macro is expanded after the new Absinthe.Relay.Mutation.Notation.Modern.payload/2 which rewrites the input and output blocks to add an identifier.

Is there a way to customize/extend the payload output macro to add generic fields with absinthe_relay 1.5?

2

@benwilson512: any idea?