class Rack::MockRequest

def request(method = GET, uri = "", opts = {})

Options given are passed to MockRequest.env_for.
uri to the rack application and return a MockResponse.
Make a request using the given request method for the given 
def request(method = GET, uri = "", opts = {})
  env = self.class.env_for(uri, opts.merge(method: method))
  if opts[:lint]
    app = Rack::Lint.new(@app)
  else
    app = @app
  end
  errors = env[RACK_ERRORS]
  status, headers, body = app.call(env)
  MockResponse.new(status, headers, body, errors)
ensure
  body.close if body.respond_to?(:close)
end