class Rack::MockRequest

def self.env_for(uri = "", opts = {})
  uri = parse_uri_rfc2396(uri)
  uri.path = "/#{uri.path}" unless uri.path[0] == ?/
  env = {}
  env[REQUEST_METHOD]  = (opts[:method] ? opts[:method].to_s.upcase : GET).b
  env[SERVER_NAME]     = (uri.host || "example.org").b
  env[SERVER_PORT]     = (uri.port ? uri.port.to_s : "80").b
  env[SERVER_PROTOCOL] = opts[:http_version] || 'HTTP/1.1'
  env[QUERY_STRING]    = (uri.query.to_s).b
  env[PATH_INFO]       = (uri.path).b
  env[RACK_URL_SCHEME] = (uri.scheme || "http").b
  env[HTTPS]           = (env[RACK_URL_SCHEME] == "https" ? "on" : "off").b
  env[SCRIPT_NAME] = opts[:script_name] || ""
  if opts[:fatal]
    env[RACK_ERRORS] = FatalWarner.new
  else
    env[RACK_ERRORS] = StringIO.new
  end
  if params = opts[:params]
    if env[REQUEST_METHOD] == GET
      params = Utils.parse_nested_query(params) if params.is_a?(String)
      params.update(Utils.parse_nested_query(env[QUERY_STRING]))
      env[QUERY_STRING] = Utils.build_nested_query(params)
    elsif !opts.has_key?(:input)
      opts["CONTENT_TYPE"] = "application/x-www-form-urlencoded"
      if params.is_a?(Hash)
        if data = Rack::Multipart.build_multipart(params)
          opts[:input] = data
          opts["CONTENT_LENGTH"] ||= data.length.to_s
          opts["CONTENT_TYPE"] = "multipart/form-data; boundary=#{Rack::Multipart::MULTIPART_BOUNDARY}"
        else
          opts[:input] = Utils.build_nested_query(params)
        end
      else
        opts[:input] = params
      end
    end
  end
  rack_input = opts[:input]
  if String === rack_input
    rack_input = StringIO.new(rack_input)
  end
  if rack_input
    rack_input.set_encoding(Encoding::BINARY) if rack_input.respond_to?(:set_encoding)
    env[RACK_INPUT] = rack_input
    env["CONTENT_LENGTH"] ||= env[RACK_INPUT].size.to_s if env[RACK_INPUT].respond_to?(:size)
  end
  opts.each { |field, value|
    env[field] = value if String === field
  }
  env
end