class Rack::Test::Session

def env_for(uri, env)
  env = DEFAULT_ENV.merge(@env).merge!(env)
  env['HTTP_HOST'] ||= [uri.host, (uri.port if uri.port != uri.default_port)].compact.join(':')
  env['HTTPS'] = 'on' if URI::HTTPS === uri
  env['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest' if env[:xhr]
  env['REQUEST_METHOD'] ||= env[:method] ? env[:method].to_s.upcase : 'GET'
  params = env.delete(:params)
  query_array = [uri.query]
  if env['REQUEST_METHOD'] == 'GET'
    # Treat params as query params
    if params
      append_query_params(query_array, params)
    end
  elsif !env.key?(:input)
    env['CONTENT_TYPE'] ||= 'application/x-www-form-urlencoded'
    params ||= {}
    multipart = env.has_key?(:multipart) ? env.delete(:multipart) : env['CONTENT_TYPE'].start_with?('multipart/')
    if params.is_a?(Hash)
      if !params.empty? && data = build_multipart(params, false, multipart)
        env[:input] = data
        env['CONTENT_LENGTH'] ||= data.length.to_s
        env['CONTENT_TYPE'] = "#{multipart_content_type(env)}; boundary=#{MULTIPART_BOUNDARY}"
      else
        env[:input] = build_nested_query(params)
      end
    else
      env[:input] = params
    end
  end
  if query_params = env.delete(:query_params)
    append_query_params(query_array, query_params)
  end
  query_array.compact!
  query_array.reject!(&:empty?)
  uri.query = query_array.join('&')
  set_cookie(env.delete(:cookie), uri) if env.key?(:cookie)
  Rack::MockRequest.env_for(uri.to_s, env)
end