Testing static routes in compojure - testing

Question

I am trying to write a test for the compojure static content route.
I am testing the routes by examining the ring response directly.
A minimal working example is as follows:
;; src/testing-webapps.core.clj
(ns testing-webapps.core
(:use [compojure.core]
[compojure.route :as route]))
(defroutes web-app
(route/resources "/")
(route/not-found "404"))
;; test/testing-webapps.core_test.clj
(ns testing-webapps.core-test
(:require [clojure.test :refer :all]
[testing-webapps.core :refer :all]))
(defn request [resource web-app & params]
(web-app {:request-method :get :uri resource :params (first params)}))
(deftest test-routes
(is (= 404 (:status (request "/flubber" web-app))))
(is (= "404" (:body (request "/flubber" web-app))))
(is (= 200 (:status (request "/test.txt" web-app)))))
Testing the 404 route works fine but calling (request "/test.txt" web-app) leads to an unexpected NullPointerException in ring.middleware.file-info/not-modified-since?.
Here is the top part of the stacktrace:
ERROR in (test-routes) (file_info.clj:27)
Uncaught exception, not in assertion.
expected: nil
actual: java.lang.NullPointerException: null
at ring.middleware.file_info$not_modified_since_QMARK_.invoke (file_info.clj:27)
ring.middleware.file_info$file_info_response.doInvoke (file_info.clj:44)
clojure.lang.RestFn.invoke (RestFn.java:442)
ring.middleware.file_info$wrap_file_info$fn__917.invoke (file_info.clj:64)
[...]
The static route works fine in the browser but not when called through my request function.
Is there an easier way to test a static route in compojure and why do I get a NullPointerException when calling the static route with my own request map?

Answer 1

Looking at the source for not-modified-since?, I think the issue is you have no headers in your request map, so it throws a NPE on this expr: (headers "if-modified-since"). Try changing your request method like so:
(defn request [resource web-app & params]
(web-app {:request-method :get
:headers {"content-type" "text/plain"} ; added a header
:uri resource
:params (first params)}))
You might also consider using ring-mock to create requests for testing. It insulates you a little bit from stuff like this.