#lang racket (require tests/eli-tester net/url web-server/lang/stuff-url web-server/stuffers/stuffer web-server/stuffers/serialize) (struct not-serializable ()) (struct serializable (x) #:prefab) (test (stuff-url serialize-stuffer (string->url "http://localhost:8000") (serializable (not-serializable))) => (error 'stuff-url "Cannot stuff '#s(serializable #) into a URL because it contains non-serializable pieces. Convert # to a serializable struct"))