#42: cleanup states that were removed from ns

dev/clj/dev.clj

@@ -2,7 +2,7 @@
   (:require [clojure.pprint :refer [pprint]]
             [clojure.tools.namespace.repl :as tn]
             [boot.core :refer [load-data-readers!]]
-            [mount.core :as mount]
+            [mount.core :as mount :refer [defstate]]
             [mount.tools.graph :refer [states-with-deps]]
             [app.utils.logging :refer [with-logging-status]]
             [app.www]

src/mount/core.cljc

@@ -188,10 +188,25 @@
           (with-ns ns name))
         v)))
 
+(defn- state-to-sym [state]
+  (->> state (drop 2) (apply str) symbol)) ;; magic 2 is removing "#'" in state name
+
+(defn- was-removed?
+  "checks if a state was removed from a namespace"
+  [state]
+  (-> state state-to-sym resolve not))
+
+(defn cleanup-deleted [state]
+  (when (was-removed? state)
+    (cleanup-if-dirty state)
+    (swap! meta-state dissoc state)))
+
 (defn- bring [states fun order]
   (let [done (atom [])]
     (as-> states $
           (map var-to-str $)
+          #?(:clj                          ;; needs more thking in cljs, since based on sym resolve
+              (remove cleanup-deleted $))
           (select-keys @meta-state $)
           (sort-by (comp :order val) order $)
           (doseq [[k v] $] (fun k v done)))

test/core/mount/test/cleanup_deleted_states.cljc

@@ -0,0 +1,40 @@
+(ns mount.test.cleanup-deleted-states
+  (:require
+    #?@(:cljs [[cljs.test :as t :refer-macros [is are deftest testing use-fixtures]]
+               [mount.core :as mount :refer-macros [defstate]]
+               [tapp.websockets :refer [system-a]]
+               [tapp.conf :refer [config]]
+               [tapp.audit-log :refer [log]]]
+        :clj  [[clojure.test :as t :refer [is are deftest testing use-fixtures]]
+               [mount.core :as mount :refer [defstate]]
+               [tapp.example]])
+   [mount.test.helper :refer [dval helper forty-two]]))
+
+(def status (atom :a-not-started))
+(defstate a :start (reset! status :a-started) 
+            :stop (reset! status :a-stopped))
+
+#?(:clj (alter-meta! *ns* assoc ::load false))
+
+#?(:clj
+    (deftest cleanup-deleted-state
+
+      (testing "should start all and remove/delete state from ns"
+        (let [started (-> (mount/start) :started set)]
+          (is (some #{"#'mount.test.cleanup-deleted-states/a"}
+                    started))
+          (is (= :a-started @status))
+          (ns-unmap 'mount.test.cleanup-deleted-states 'a)
+          (is (nil? (resolve 'mount.test.cleanup-deleted-states/a)))))
+
+      (testing "should cleanup/stop a state after it was deleted from ns"
+          (is (empty? (:started (mount/start)))) ;; on any mount op (not necessarily on "stop")
+          (is (= :a-stopped @status))
+          (is (not (some #{"#'mount.test.cleanup-deleted-states/a"} 
+                         (keys @@#'mount.core/meta-state)))))
+
+      (testing "should not stop it again on stop (should not be there by this point)")
+          (is (not (some #{"#'mount.test.cleanup-deleted-states/a"} 
+                         (-> (mount/stop) :stopped set))))))
+
+;; (t/run-tests)