Absinthe Auth

auth_middleware

defmodule Api.Graphql.AuthMiddleware do
  @behaviour Absinthe.Middleware

  def call(resolution, _config) do
    case resolution.context[:authenticated] do
      true  -> resolution
      _ -> Absinthe.Resolution.put_result(resolution, {:error, "Unauthorized"});
    end
  end
end

schema.ex

defmodule Api.Graphql.Schema do
  use Absinthe.Schema
  use Absinthe.Relay.Schema
  alias Api.Graphql.{Types, AuthMiddleware}

  import_types Types.ViewerType

  # Relay
  node interface do
    resolve_type fn
      %{}, _ -> :viewer
      _, _   -> nil
    end
  end

  def middleware(middleware, _field, %Absinthe.Type.Object{identifier: :user}) do
    [AuthMiddleware | middleware]
  end

  def middleware(middleware, _field, _) do
    middleware
  end
end

user.ex

defmodule Api.Graphql.Types.User do
  use Api.Graphql.Types

  node object :user do
    field :id, :id
    field :name, :string
  end

  connection node_type: :user
end

viewer_type.ex

defmodule Api.Graphql.Types.ViewerType do
  use Api.Graphql.Types
  alias Api.Graphql.Types

  import_types Types.User

  node object :viewer do
    field :id, :id

    # User
    field :user, type: :user do
      arg :id, non_null(:id)
      resolve parsing_node_ids(&Resolver.User.find/2, id: :user)
    end

    connection field :users, node_type: :user do
      resolve &Resolver.User.all/2
    end
  end
end