module GraphQL::StaticValidation::OperationNamesAreValid

def initialize(*)
  super
  @operation_names = Hash.new { |h, k| h[k] = [] }
end

def on_document(node, parent)
  super
  op_count = @operation_names.values.inject(0) { |m, v| m + v.size }
  @operation_names.each do |name, nodes|
    if name.nil? && op_count > 1
      add_error(GraphQL::StaticValidation::OperationNamesAreValidError.new(
        %|Operation name is required when multiple operations are present|,
        nodes: nodes
      ))
    elsif nodes.length > 1
      add_error(GraphQL::StaticValidation::OperationNamesAreValidError.new(
        %|Operation name "#{name}" must be unique|,
        nodes: nodes,
        name: name
      ))
    end
  end
end

def on_operation_definition(node, parent)
  @operation_names[node.name] << node
  super
end