Pedestal Routing Question

pedestal-routing-question.clj

; Types of Pedestal Routes 

; Example A - Tabular Routes (adapted from pedestal leiningen template
(def routes #{["/"      :get `home-page]
              ["/about" :get `about-page]})

; Example B - table-routes (adapted from http://pedestal.io/reference/table-syntax#_detailed_reference)             
(ns myapp.service
  (:require [io.pedestal.http.route.definition.table :as table]))

(def application-routes
  (table/table-routes
    [["/"      :get home-page]
     ["/about" :get about-page]]))

; Example C - expand-routes (adapted from http://pedestal.io/reference/table-syntax#_detailed_reference)
(ns myapp.service
  (:require [io.pedestal.http.route :as route]))

(def application-routes
  (route/expand-routes
    #{["/"      :get home-page]
      ["/about" :get about-page]}))

; Questions 
; Q1 - In http://pedestal.io/reference/routing-quick-reference, there is an example with the following code
; Is there a reason this example uses syntax quoting while example C above does not?
 (route/expand-routes
      #{["/user/:id"  :post [,,, `new-user]  :constraints {:user-id #"[0-9]+"}]
        ["/user/:id"  :get  [,,, `view-user] :constraints {:user-id #"[0-9]+"}]})

 
 ; Q2 - When referring to table-syntax, is does that mean example A or example B?

Example C only works for me if I syntax quote the handler symbols or add a :route-name.

Example A is the tabular route syntax.

Also, don't use route/expand-routes if http/default-interceptors is being called. This happens internally if ::http/interceptors is not set on the service map. Your tests using response-for may pass, but the running system will fail with an error like

clojure.lang.ExceptionInfo: Interceptor Exception: You're trying to use something as a route specification that isn't supported by the protocol; Perhaps you need to extend it?

The reason is that route/expand-routes returns a verbose route map and the ExpandableRoutes protocol is extended to maps. When default-interceptors is called, it tries to expand it again.