diff --git a/src/main/frontend/worker/db/fix.cljs b/src/main/frontend/worker/db/fix.cljs
index 2bbabd3c8..484057a8b 100644
--- a/src/main/frontend/worker/db/fix.cljs
+++ b/src/main/frontend/worker/db/fix.cljs
@@ -9,14 +9,21 @@
             [frontend.worker.util :as worker-util]))
 
 (defn- fix-parent-broken-chain
-  [db parent-id]
+  [db parent-id tx-report]
   (let [parent (d/entity db parent-id)
         parent-id (:db/id parent)
         blocks (:block/_parent parent)]
     (when (seq blocks)
       (let [children-ids (set (map :db/id blocks))
             sorted (ldb/sort-by-left blocks parent)
-            broken-chain? (not= (count sorted) (count blocks))]
+            valid-left-ids (set (cons (:db/id parent) (map :db/id blocks)))
+            broken-chain? (or (not= (count sorted) (count blocks))
+                              ;; :block/left points to other blocks that're not current parent or its children
+                              (not (every? (fn [b] (contains? valid-left-ids (:db/id (:block/left b)))) blocks)))]
+        (when (and (exists? js/process) broken-chain?)
+          (throw (ex-info "outliner broken chain" {:tx-meta (:tx-meta tx-report)
+                                                   :tx-data (:tx-data tx-report)
+                                                   :db-before (:db-before tx-report)})))
         (when broken-chain?
           (let [error-data {:parent {:db/id parent-id
                                      :block/uuid (:block/uuid parent)
@@ -92,9 +99,9 @@
              (apply concat))))))))
 
 (defn- fix-broken-chain
-  [db parent-left->es]
+  [db parent-left->es tx-report]
   (let [parents (distinct (map first (keys parent-left->es)))]
-    (mapcat #(fix-parent-broken-chain db %) parents)))
+    (mapcat #(fix-parent-broken-chain db % tx-report) parents)))
 
 (defn- build-parent-left->es
   [db page-id]
@@ -142,6 +149,8 @@
   [conn page-id transact-opts *fix-tx-data]
   (let [db @conn
         conflicts (get-conflicts db page-id)
+        _ (when (and (exists? js/process) (seq conflicts))
+            (throw (ex-info "outliner core conflicts" {:conflicts conflicts})))
         fix-conflicts-tx (when (seq conflicts)
                            (fix-parent-left-conflicts db conflicts page-id))]
     (when (seq fix-conflicts-tx)
@@ -154,7 +163,7 @@
 
 (defn fix-page-if-broken!
   "Fix the page if it has either parent-left conflicts or broken chains."
-  [conn page-id {:keys [fix-parent-left? fix-broken-chain? replace-tx?]
+  [conn page-id {:keys [fix-parent-left? fix-broken-chain? replace-tx? tx-report]
                  :or {fix-parent-left? true
                       fix-broken-chain? true
                       replace-tx? false}
@@ -170,7 +179,7 @@
         (when fix-broken-chain?
           (let [db' @conn
                 parent-left->es' (build-parent-left->es db page-id)
-                fix-broken-chain-tx (fix-broken-chain db' parent-left->es')]
+                fix-broken-chain-tx (fix-broken-chain db' parent-left->es' tx-report)]
             (when (seq fix-broken-chain-tx)
               (let [tx-data (:tx-data (ldb/transact! conn fix-broken-chain-tx transact-opts))]
                 (swap! *fix-tx-data (fn [old-data] (concat old-data tx-data)))))))
diff --git a/src/main/frontend/worker/pipeline.cljs b/src/main/frontend/worker/pipeline.cljs
index 78c7d8579..e0f478b00 100644
--- a/src/main/frontend/worker/pipeline.cljs
+++ b/src/main/frontend/worker/pipeline.cljs
@@ -49,7 +49,7 @@
        (remove nil?)))))
 
 (defn fix-db!
-  [conn {:keys [db-before db-after tx-data]}]
+  [conn {:keys [db-before db-after tx-data] :as tx-report}]
   (let [changed-pages (->> (filter (fn [d] (contains? #{:block/left :block/parent} (:a d))) tx-data)
                            (map :e)
                            distinct
@@ -61,7 +61,7 @@
                            (remove nil?)
                            (distinct))]
     (doseq [changed-page-id changed-pages]
-      (db-fix/fix-page-if-broken! conn changed-page-id {}))))
+      (db-fix/fix-page-if-broken! conn changed-page-id {:tx-report tx-report}))))
 
 (defn validate-and-fix-db!
   [repo conn tx-report context]
@@ -70,8 +70,8 @@
       (when (and (get-in context [:validate-db-options :fail-invalid?]) (not valid?))
         (worker-util/post-message :notification
                                   [["Invalid DB!"] :error]))))
-  (when (and (:dev? context)
-             (not (:node-test? context)))
+  (when (or (:dev? context)
+            (exists? js/process))
     (fix-db! conn tx-report)))
 
 (defn invoke-hooks
diff --git a/src/test/frontend/worker/fixtures.cljs b/src/test/frontend/worker/fixtures.cljs
index 3be8f5124..69f152446 100644
--- a/src/test/frontend/worker/fixtures.cljs
+++ b/src/test/frontend/worker/fixtures.cljs
@@ -12,7 +12,7 @@
     (assert (some? test-db-conn))
     (worker-undo-redo/clear-undo-redo-stack)
     (worker-db-listener/listen-db-changes! test-helper/test-db-name-db-version test-db-conn
-                                           {:handler-keys [:gen-undo-ops]})
+                                           {:handler-keys [:gen-undo-ops :sync-db-to-main-thread]})
 
     (f)
     (d/unlisten! test-db-conn :frontend.worker.db-listener/listen-db-changes!)))
diff --git a/src/test/frontend/worker/undo_redo_test.cljs b/src/test/frontend/worker/undo_redo_test.cljs
index b6ffd1bf6..a7ee942ae 100644
--- a/src/test/frontend/worker/undo_redo_test.cljs
+++ b/src/test/frontend/worker/undo_redo_test.cljs
@@ -275,7 +275,7 @@
     (catch :default e
       (let [data (ex-data e)]
         (fs-node/writeFileSync "debug.json" (sqlite-util/write-transit-str data))
-        (throw (ex-info "stop now" {}))))))
+        (throw e)))))