From 6b68815f246d900e1b1f593487779f3ecef64767 Mon Sep 17 00:00:00 2001
From: Juho Teperi <juho.teperi@iki.fi>
Date: Fri, 28 Feb 2020 16:58:33 +0200
Subject: [PATCH] Ensure render sees the up-to-date props

---
 src/reagent/impl/component.cljs   | 20 ++++++++++++--------
 src/reagent/ratom.cljs            |  3 +--
 test/reagenttest/testreagent.cljs |  7 +++----
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/src/reagent/impl/component.cljs b/src/reagent/impl/component.cljs
index 1f3b49e..be310f6 100644
--- a/src/reagent/impl/component.cljs
+++ b/src/reagent/impl/component.cljs
@@ -399,8 +399,6 @@
     comp
     (as-class comp)))
 
-(defonce fun-component-state #js {})
-
 (defn functional-wrap-render
   [^clj c argv]
   (let [f (.-reagentRender c)
@@ -416,19 +414,21 @@
                    (recur c argv))
       :else res)))
 
-(defn functional-do-render [c argv]
+(defn functional-do-render [c]
   (binding [*current-component* c]
     (if (dev?)
       ;; Log errors, without using try/catch (and mess up call stack)
       (let [ok (array false)]
         (try
-          (let [res (functional-wrap-render c argv)]
+          (let [res (functional-wrap-render c (.-argv c))]
             (aset ok 0 true)
             res)
           (finally
             (when-not (aget ok 0)
               (error (str "Error rendering component" (comp-name)))))))
-      (functional-wrap-render c argv))))
+      (functional-wrap-render c (.-argv c)))))
+
+(def fun-component-state #js {})
 
 (defn functional-render [jsprops]
   (let [argv (.-argv jsprops)
@@ -465,7 +465,10 @@
                                              ;; constructor refers to the original fn.
                                              :reagentRender tag
                                              :constructor tag
-                                             :cljsIsDirty false}]
+                                             :cljsIsDirty false
+                                             ;; Argv is also stored in the state,
+                                             ;; so reaction fn will always see the latest value.
+                                             :argv argv}]
                                 (gobj/set fun-component-state id obj)
                                 obj))]
 
@@ -479,19 +482,20 @@
 
         (assert-callable tag)
         (batch/mark-rendered reagent-state)
+        (set! (.-argv reagent-state) argv)
 
         ;; static-fns :render
         (if-let [rat (gobj/get reagent-state "cljsRatom")]
           (._run rat false)
           (ratom/run-in-reaction
             ;; Mock Class component API
-            #(functional-do-render reagent-state argv)
+            #(functional-do-render reagent-state)
             reagent-state
             "cljsRatom"
             batch/queue-render
             rat-opts))))))
 
-(defonce fun-components #js {})
+(def fun-components #js {})
 
 (defn funtional-render-fn
   "Create copy of functional-render with displayName set to name of the
diff --git a/src/reagent/ratom.cljs b/src/reagent/ratom.cljs
index fe396d2..c9129b9 100644
--- a/src/reagent/ratom.cljs
+++ b/src/reagent/ratom.cljs
@@ -338,8 +338,7 @@
 
 (defn with-let-values [key]
   (if-some [c *ratom-context*]
-    (cached-reaction array c key
-                     nil with-let-destroy)
+    (cached-reaction array c key nil with-let-destroy)
     (array)))
 
 
diff --git a/test/reagenttest/testreagent.cljs b/test/reagenttest/testreagent.cljs
index 25a758d..a5df8fe 100644
--- a/test/reagenttest/testreagent.cljs
+++ b/test/reagenttest/testreagent.cljs
@@ -145,8 +145,7 @@
           v2 (r/atom 0)
           c2 (fn [{val :val}]
                (swap! ran inc)
-               ;; FIXME:
-               ; (is (= val @v1))
+               (is (= val @v1))
                [:div @v2])
           c1 (fn []
                (swap! ran inc)
@@ -663,9 +662,9 @@
              [:div "" (reset! spy @(r/track t1))])]
     (with-mounted-component [c2]
       (fn [c div]
-        ;; FIXME:
-        ; (is (= {:v1 1 :v2 1} @v))
+        (is (= {:v1 1 :v2 1} @v))
 
+        ;; FIXME:
         ; (r/force-update (:c2 @comps))
         ; (is (= {:v1 1 :v2 2} @v))