From 9c2f26bdb953c2e8c406771d32ced1a8016abf65 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuel.susla@gmail.com>
Date: Fri, 9 Sep 2022 18:50:53 +0100
Subject: [PATCH] Refactor double invoking logic into single if/else statement

---
 .../src/ReactFiberWorkLoop.new.js             | 26 ++++++++++---------
 .../src/ReactFiberWorkLoop.old.js             | 26 ++++++++++---------
 2 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
index a40b5ac480728..c18575b52bc74 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
@@ -3186,19 +3186,21 @@ function doubleInvokeEffectsInDEV(
   const isStrictModeFiber = fiber.type === REACT_STRICT_MODE_TYPE;
   const isInStrictMode = parentIsInStrictMode || isStrictModeFiber;
 
-  if (fiber.flags & PlacementDEV || fiber.tag === OffscreenComponent) {
+  if (
+    isInStrictMode &&
+    // Check for newly mounted trees
+    (fiber.flags & PlacementDEV ||
+      // Check for trees that are going from hidden -> visible
+      (fiber.tag === OffscreenComponent &&
+        fiber.flags & Visibility &&
+        fiber.memoizedState === null))
+  ) {
+    // Double invoke all the effects in this tree
     setCurrentDebugFiberInDEV(fiber);
-    const isNotOffscreen = fiber.tag !== OffscreenComponent;
-    // Checks if Offscreen is being revealed. For all other components, evaluates to true.
-    const hasOffscreenBecomeVisible =
-      isNotOffscreen ||
-      (fiber.flags & Visibility && fiber.memoizedState === null);
-    if (isInStrictMode && hasOffscreenBecomeVisible) {
-      disappearLayoutEffects(fiber);
-      disconnectPassiveEffect(fiber);
-      reappearLayoutEffects(root, fiber.alternate, fiber, false);
-      reconnectPassiveEffects(root, fiber, NoLanes, null, false);
-    }
+    disappearLayoutEffects(fiber);
+    disconnectPassiveEffect(fiber);
+    reappearLayoutEffects(root, fiber.alternate, fiber, false);
+    reconnectPassiveEffects(root, fiber, NoLanes, null, false);
     resetCurrentDebugFiberInDEV();
   } else {
     recursivelyTraverseAndDoubleInvokeEffectsInDEV(root, fiber, isInStrictMode);
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
index 3db85b0b9b23b..91be9dd4707f2 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
@@ -3186,19 +3186,21 @@ function doubleInvokeEffectsInDEV(
   const isStrictModeFiber = fiber.type === REACT_STRICT_MODE_TYPE;
   const isInStrictMode = parentIsInStrictMode || isStrictModeFiber;
 
-  if (fiber.flags & PlacementDEV || fiber.tag === OffscreenComponent) {
+  if (
+    isInStrictMode &&
+    // Check for newly mounted trees
+    (fiber.flags & PlacementDEV ||
+      // Check for trees that are going from hidden -> visible
+      (fiber.tag === OffscreenComponent &&
+        fiber.flags & Visibility &&
+        fiber.memoizedState === null))
+  ) {
+    // Double invoke all the effects in this tree
     setCurrentDebugFiberInDEV(fiber);
-    const isNotOffscreen = fiber.tag !== OffscreenComponent;
-    // Checks if Offscreen is being revealed. For all other components, evaluates to true.
-    const hasOffscreenBecomeVisible =
-      isNotOffscreen ||
-      (fiber.flags & Visibility && fiber.memoizedState === null);
-    if (isInStrictMode && hasOffscreenBecomeVisible) {
-      disappearLayoutEffects(fiber);
-      disconnectPassiveEffect(fiber);
-      reappearLayoutEffects(root, fiber.alternate, fiber, false);
-      reconnectPassiveEffects(root, fiber, NoLanes, null, false);
-    }
+    disappearLayoutEffects(fiber);
+    disconnectPassiveEffect(fiber);
+    reappearLayoutEffects(root, fiber.alternate, fiber, false);
+    reconnectPassiveEffects(root, fiber, NoLanes, null, false);
     resetCurrentDebugFiberInDEV();
   } else {
     recursivelyTraverseAndDoubleInvokeEffectsInDEV(root, fiber, isInStrictMode);