fix unmount bug

core/src/refx/hooks.cljs

@@ -28,7 +28,7 @@
  (react/useMemo
  (fn []
  [(fn [callback]
- (let [key {:index (swap! use-sub-counter inc)}]
+ (let [key {::subs/index (swap! use-sub-counter inc)}]
  (subs/-add-listener sub key callback)
  #(subs/-remove-listener sub key)))
  (fn []

core/src/refx/subs.cljc

@@ -5,6 +5,13 @@
 
 (def kind :sub)
 
+(defn ui-sub?
+ "UI subscriptions are batched together and invoked after all subs
+ finish computing their new values. This is done to reduce renders and
+ prevent consumers from having an inconsistent view of the DB."
+ [sub-key]
+ (some? (::index sub-key)))
+
 ;; --- signals ----------------------------------------------------------------
 
 (defprotocol ISignal
@@ -78,7 +85,7 @@
 
 (defonce ^:private listeners-state
  (letfn [(comparator [a b]
- (compare (:index a) (:index b)))]
+ (compare (::index a) (::index b)))]
  (atom {:counter 0 :pending (sorted-map-by comparator)})))
 
 (defn- invoke-listener
@@ -103,16 +110,20 @@
 
  (interop/next-tick
  (fn []
- (let [listener-fns (atom nil)]
- (swap! listeners-state (fn [state]
- (let [{:keys [counter pending] :as new-state}
- (update state :counter dec)]
- (if (zero? counter)
- (do (reset! listener-fns pending)
- (update new-state :pending empty))
- new-state))))
- (doseq [[_ f] @listener-fns]
- (f)))))))
+ (let [{:keys [counter pending]}
+ (swap! listeners-state update :counter dec)]
+
+ (when (zero? counter)
+ (doseq [[listener-key _] pending]
+ ;; Triggering a listener-fn can result in a subsequent sub's
+ ;; remove-listener to be called (which will remove it from pending).
+ ;; This check ensure it's still pending.
+ (let [listener-fn (atom nil)]
+ (swap! listeners-state (fn [state]
+ (reset! listener-fn (get-in state [:pending listener-key]))
+ (update state :pending dissoc listener-key)))
+ (when-let [f @listener-fn]
+ (f))))))))))
 
 (deftype Listeners [^:mutable listeners]
  Object
@@ -160,6 +171,8 @@
  (-add-listener [_ k f]
  (.add listeners k f))
  (-remove-listener [this k]
+ (when (ui-sub? k)
+ (swap! listeners-state update :pending dissoc k))
  (.remove listeners k)
  (when (.empty? listeners)
  (sub-orphaned this)))
@@ -238,6 +251,8 @@
  (-add-listener [_ k f]
  (.add listeners k f))
  (-remove-listener [this k]
+ (when (ui-sub? k)
+ (swap! listeners-state update :pending dissoc k))
  (.remove listeners k)
  (when (.empty? listeners)
  (sub-orphaned this)))

core/test/refx/subs_test.cljs

@@ -119,7 +119,7 @@
  listener-calls (atom [])
  remove-listener-fns (atom '())
  add-listener! (fn [sub]
- (let [key {:index (swap! listener-count inc)}]
+ (let [key {::subs/index (swap! listener-count inc)}]
  (subs/-add-listener sub key #(swap! listener-calls conj key))
  (swap! remove-listener-fns conj #(subs/-remove-listener sub key))))
  remove-listeners! (fn []
@@ -130,13 +130,13 @@
  (add-listener! sub-c)
  (add-listener! sub-d)
  (reset! source 1)
- (remove-listeners!)
  (async done
  (js/setTimeout (fn []
+ (remove-listeners!)
  (is (= @listener-calls
- [{:index 1}
- {:index 2}
- {:index 3}
- {:index 4}]))
+ [{::subs/index 1}
+ {::subs/index 2}
+ {::subs/index 3}
+ {::subs/index 4}]))
  (done))
  10)))))