From 38906fb369d060da6ad3150071cd974f5c4cdb54 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuel.susla@gmail.com>
Date: Sun, 11 Sep 2022 12:39:07 +0100
Subject: [PATCH] Add early exit to strict mode

---
 packages/react-reconciler/src/ReactFiberWorkLoop.new.js | 5 +++++
 packages/react-reconciler/src/ReactFiberWorkLoop.old.js | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
index a40b5ac480728..2ec9068408325 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
@@ -3171,6 +3171,11 @@ function recursivelyTraverseAndDoubleInvokeEffectsInDEV(
   parentFiber: Fiber,
   isInStrictMode: boolean,
 ) {
+  if ((parentFiber.subtreeFlags & (PlacementDEV | Visibility)) === NoFlags) {
+    // Parent's descendants have already had effects double invoked.
+    // Early exit to avoid unnecessary tree traversal.
+    return;
+  }
   let child = parentFiber.child;
   while (child !== null) {
     doubleInvokeEffectsInDEV(root, child, isInStrictMode);
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
index 3db85b0b9b23b..a6ce27ff50203 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
@@ -3171,6 +3171,11 @@ function recursivelyTraverseAndDoubleInvokeEffectsInDEV(
   parentFiber: Fiber,
   isInStrictMode: boolean,
 ) {
+  if ((parentFiber.subtreeFlags & (PlacementDEV | Visibility)) === NoFlags) {
+    // Parent's descendants have already had effects double invoked.
+    // Early exit to avoid unnecessary tree traversal.
+    return;
+  }
   let child = parentFiber.child;
   while (child !== null) {
     doubleInvokeEffectsInDEV(root, child, isInStrictMode);