Add ring session middleware

.gitignore

@@ -6,7 +6,7 @@ pom.xml.asc
 *.jar
 *.class
 /.lein-*
-/.nrepl-port
+.nrepl-port
 /.nrepl-history
 /gh-pages
 /node_modules

modules/reitit-middleware/src/reitit/ring/middleware/session.clj

@@ -0,0 +1,40 @@
+(ns reitit.ring.middleware.session
+ (:require
+ [clojure.spec.alpha :as s]
+ [ring.middleware.session :as session]
+ [ring.middleware.session.store :as session-store]
+ [ring.middleware.session.memory :as memory]))
+
+(s/def ::store #(satisfies? session-store/SessionStore %))
+(s/def ::root string?)
+(s/def ::cookie-name string?)
+(s/def ::cookie-attrs map?)
+(s/def ::session (s/keys :opt-un [::store ::root ::cookie-name ::cookie-attrs]))
+(s/def ::spec (s/keys :opt-un [::session]))
+
+(def ^:private store
+ "The default shared in-memory session store.
+
+ This is used when no `:store` key is provided to the middleware."
+ (memory/memory-store (atom {})))
+
+(def session-middleware
+ "Middleware for session.
+
+ Enter:
+ Add the `:session` key into the request map based on the `:cookies`
+ in the request map.
+
+ Exit:
+ When `:session` key presents in the response map, update the session
+ store with its value. Then remove `:session` from the response map.
+
+ | key | description |
+ | -------------|-------------|
+ | `:session` | A map of options that passes into the [`ring.middleware.session/wrap-session](http://ring-clojure.github.io/ring/ring.middleware.session.html#var-wrap-session) function`, or an empty map for the default options. The absence of this value will disable the middleware."
+ {:name :session
+ :spec ::spec
+ :compile (fn [{session-opts :session} _]
+ (if session-opts
+ (let [session-opts (merge {:store store} session-opts)]
+ {:wrap #(session/wrap-session % session-opts)})))})

test/clj/reitit/ring/middleware/session_test.clj

@@ -0,0 +1,92 @@
+(ns reitit.ring.middleware.session-test
+ (:require [clojure.test :refer [deftest testing is]]
+ [reitit.ring.middleware.session :as session]
+ [ring.middleware.session.memory :as memory]
+ [reitit.spec :as rs]
+ [reitit.ring :as ring]
+ [reitit.ring.spec :as rrs]))
+
+(defn get-session-id
+ "Parse the session-id out of response headers."
+ [request]
+ (let [pattern #"ring-session=([-\w]+);Path=/;HttpOnly"
+ parse-fn (partial re-find pattern)]
+ (some-> request
+ (get-in [:headers "Set-Cookie"])
+ first
+ parse-fn
+ second)))
+
+(defn handler
+ "The handler that increments the counter."
+ [{session :session}]
+ (let [counter (inc (:counter session 0))]
+ {:status 200
+ :body {:counter counter}
+ :session {:counter counter}}))
+
+(deftest session-test
+ (testing "Custom session store"
+ (let [store (atom {})
+ app (ring/ring-handler
+ (ring/router
+ ["/api"
+ {:session {:store (memory/memory-store store)}
+ :middleware [session/session-middleware]}
+ ["/ping" handler]
+ ["/pong" handler]]))
+ first-response (app {:request-method :get
+ :uri "/api/ping"})
+ session-id (get-session-id first-response)
+ second-response (app {:request-method :get
+ :uri "/api/pong"
+ :cookies {"ring-session" {:value session-id}}})]
+ (testing "shared across routes"
+ (is (= (count @store)
+ 1))
+ (is (-> @store first second)
+ {:counter 2})))))
+
+(deftest default-session-test
+ (testing "Default session store"
+ (let [app (ring/ring-handler
+ (ring/router
+ ["/api"
+ {:middleware [session/session-middleware]
+ :session {}}
+ ["/ping" handler]
+ ["/pong" handler]]))
+ first-response (app {:request-method :get
+ :uri "/api/ping"})
+ session-id (get-session-id first-response)
+ second-response (app {:request-method :get
+ :uri "/api/pong"
+ :cookies {"ring-session" {:value session-id}}})]
+ (testing "shared across routes"
+ (is (= (inc (get-in first-response [:body :counter]))
+ (get-in second-response [:body :counter])))))))
+
+(deftest default-session-off-test
+ (testing "Default session middleware"
+ (let [app (ring/ring-handler
+ (ring/router
+ ["/api"
+ {:middleware [session/session-middleware]}
+ ["/ping" handler]]))
+ resp (app {:request-method :get
+ :uri "/api/ping"})]
+ (testing "off by default"
+ (is (nil? (get-session-id resp)))))))
+
+(deftest session-spec-test
+ (testing "Session spec"
+ (testing "with invalid session store type"
+ (is
+ (thrown? Exception
+ (ring/ring-handler
+ (ring/router
+ ["/api"
+ {:session {:store nil}
+ :middleware [session/session-middleware]
+ :handler handler}]
+ {:validate rrs/validate})))))))