module GraphQL::InternalRepresentation::Visit

def each_node(node, &block)
  yield(node)
  node.typed_children.each do |obj_type, children|
    children.each do |name, node|
      each_node(node, &block)
    end
  end
end

def visit_each_node(operations, handlers)
  return if handlers.empty?
  # Post-validation: make some assertions about the rewritten query tree
  operations.each do |op_name, op_node|
    # Yield each node to listeners which were attached by validators
    op_node.typed_children.each do |obj_type, children|
      children.each do |name, op_child_node|
        each_node(op_child_node) do |node|
          for h in handlers
            h.call(node)
          end
        end
      end
    end
  end
end