name : content_length.rb # frozen_string_literal: true module Rack # Sets the Content-Length header on responses that do not specify # a Content-Length or Transfer-Encoding header. Note that this # does not fix responses that have an invalid Content-Length # header specified. class ContentLength include Rack::Utils def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) headers = HeaderHash[headers] if !STATUS_WITH_NO_ENTITY_BODY.key?(status.to_i) && !headers[CONTENT_LENGTH] && !headers[TRANSFER_ENCODING] obody = body body, length = [], 0 obody.each { |part| body << part; length += part.bytesize } body = BodyProxy.new(body) do obody.close if obody.respond_to?(:close) end headers[CONTENT_LENGTH] = length.to_s end [status, headers, body] end end end