diff --git a/src/main/frontend/async_util.cljc b/src/main/frontend/async_util.cljc
index db363dbba8..eedd2dedb3 100644
--- a/src/main/frontend/async_util.cljc
+++ b/src/main/frontend/async_util.cljc
@@ -1,4 +1,6 @@
-(ns frontend.async-util)
+(ns frontend.async-util
+  "Some cljs.core.async relate macros and fns.
+  see also: https://gist.github.com/vvvvalvalval/f1250cec76d3719a8343")
 
 (defmacro go-try
   [& body]
diff --git a/src/main/frontend/db/rtc/const.cljs b/src/main/frontend/db/rtc/const.cljs
index f08fddf13b..343dc9221a 100644
--- a/src/main/frontend/db/rtc/const.cljs
+++ b/src/main/frontend/db/rtc/const.cljs
@@ -113,7 +113,7 @@
         [:block-uuid :uuid]]]]]]
    [:ex-data {:optional true} [:map [:type :keyword]]]
    [:ex-message {:optional true} :any]])
-(def data-from-ws-decoder (m/decoder data-from-ws-schema mt/string-transformer))
+
 (def data-from-ws-coercer (m/coercer data-from-ws-schema mt/string-transformer))
 (def data-from-ws-validator (m/validator data-from-ws-schema))
 
diff --git a/src/main/frontend/db/rtc/core.cljs b/src/main/frontend/db/rtc/core.cljs
index 63210c0f4c..f750ae3d05 100644
--- a/src/main/frontend/db/rtc/core.cljs
+++ b/src/main/frontend/db/rtc/core.cljs
@@ -17,7 +17,7 @@
             [frontend.modules.outliner.transaction :as outliner-tx]
             [frontend.state :as state]
             [frontend.util :as util]
-            [frontend.async-util :include-macros true :refer [<? go-try]]
+            [frontend.async-util :include-macros true :refer [<?]]
             [malli.core :as m]
             [malli.util :as mu]))
 
diff --git a/src/main/frontend/db/rtc/op_mem_layer.cljs b/src/main/frontend/db/rtc/op_mem_layer.cljs
index 94539d4032..fe4251f4d4 100644
--- a/src/main/frontend/db/rtc/op_mem_layer.cljs
+++ b/src/main/frontend/db/rtc/op_mem_layer.cljs
@@ -278,7 +278,7 @@
   use `rollback` to replace current-branch with old-branch.
   use `commit` to remove old-branch."
   [repo]
-  (let [{:keys [current-branch old-branch]} (get @*ops-store repo)]
+  (let [{:keys [current-branch]} (get @*ops-store repo)]
     (assert (some? current-branch) repo)
     (swap! *ops-store assoc-in [repo :old-branch] current-branch)))
 
diff --git a/src/main/frontend/db/rtc/ws.cljs b/src/main/frontend/db/rtc/ws.cljs
index 72c14487aa..69fafecba8 100644
--- a/src/main/frontend/db/rtc/ws.cljs
+++ b/src/main/frontend/db/rtc/ws.cljs
@@ -3,12 +3,12 @@
   (:require-macros
    [frontend.db.rtc.macro :refer [with-sub-data-from-ws get-req-id get-result-ch]])
   (:require [cljs-http.client :as http]
-            [cljs.core.async :as async :refer [<! chan go offer!]]
+            [cljs.core.async :as async :refer [<! chan offer!]]
+            [frontend.async-util :include-macros true :refer [<? go-try]]
             [frontend.config :as config]
             [frontend.db.rtc.const :as rtc-const]
             [frontend.state :as state]
-            [frontend.util :as util]
-            [frontend.async-util :include-macros true :refer [go-try <?]]))
+            [frontend.util :as util]))
 
 (def WebSocketOPEN (if (= *target* "nodejs")
                      1