module GraphQL::Types::Relay::HasNodesField

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

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

def field_options
  {
    name: "nodes",
    type: [GraphQL::Types::Relay::Node, null: true],
    null: false,
    description: "Fetches a list of objects given a list of IDs.",
    relay_nodes_field: true,
  }
end

def resolve(obj, args, ctx)
  args[:ids].map { |id| ctx.schema.object_from_id(id, ctx) }
end

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