Abstractions

(ns darkleaf.di.tutorial.m-abstractions-test
  (:require
   [clojure.test :as t]
   [darkleaf.di.core :as di]))

For some reasons, we may want to not depend on specific vars. In this case, use keywords instead of symbols to define dependencies. Later in the main function you will be able to bind all parts of your application.

(defn get-user [{ds ::datasource} id]
  (ds id))

(defn get-current-user [{session  ::session
                         get-user `get-user}]
  (-> session :user-id get-user))

(defn ring-handler [{get-current-user `get-current-user} -req]
  {:status 200 :body (str "Hi, " (get-current-user) "!")})

(t/deftest handler-test
  (with-open [root (di/start `ring-handler
                             {::datasource {1 "John"}
                              ::session    {:user-id 1}})]
    (t/is (= {:status 200 :body "Hi, John!"}
             (root {})))))