Slash appended to request path

Question

I'm working on a SCIM api using https://github.com/elimity-com/scim, which gives me an http.Handler that I have mounted using app.Mount("/api/v1/scim", scimHandler). Requests route to the scim handler, but have a trailing / appended to them which confuses the handler. For instance, if I request /api/v1/scim/Users (a list request), the handler sees /api/v1/scim/Users/ (a get-by-id request with no id). Similarly, if I request /api/v1/scim/Users/${id}, the handler sees /api/v1/scim/Users/${id}/ and fails to parse to the id properly.

I see similar appending of slash to other paths that aren't using Mount, but Buffalo seems to handle routing those ok. My /elb_health_check route gets to the handler as /elb_health_check/, but it does still get routed correctly and the health check doesn't care because it doesn't inspect the path.

Is there an option disable this behavior? Is it a bug I should report as an issue?

Answer 1

I'm not really happy with this workaround, but for now I've added a wrapper that strips the trailing slash.

app.Mount("/api/v1/scim", stripTrailingSlash(scimHandler))

...

func stripTrailingSlash(h http.Handler) http.Handler {
  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    path := r.URL.Path
    path = strings.TrimSuffix(path, "/")

    url, err := url.Parse(path)
    if err != nil {
      // Fall back to serving unmodified URL
      h.ServeHTTP(w, r)
      return
    }

    r.URL = url
    h.ServeHTTP(w, r)
  })
}