module GraphQL::Types::Relay::HasNodeField

def self.included(child_class)
  child_class.field(**field_options, &field_block)
end

def field_block
  Proc.new {
    argument :id, "ID!",
      description: "ID of the object."
    def resolve(obj, args, ctx)
      ctx.schema.object_from_id(args[:id], ctx)
    end
    def resolve_field(obj, args, ctx)
      resolve(obj, args, ctx)
    end
  }
end

def field_options
  {
    name: "node",
    type: GraphQL::Types::Relay::Node,
    null: true,
    description: "Fetches an object given its ID.",
    relay_node_field: true,
  }
end

def resolve(obj, args, ctx)
  ctx.schema.object_from_id(args[:id], ctx)
end

def resolve_field(obj, args, ctx)
  resolve(obj, args, ctx)
end