From 7e4171a5c3f7520d916d5666a15539749c9c5acf Mon Sep 17 00:00:00 2001
From: Dongda Li <dongdongbhbh@gmail.com>
Date: Fri, 7 Aug 2026 22:05:58 -0400
Subject: [PATCH] fix(ios): make unmount assert message bounds-safe

---
 .../Mounting/ComponentViews/View/RCTViewComponentView.mm | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
index 223670890e9..39746243264 100644
--- a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
+++ b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
@@ -255,15 +255,16 @@ - (void)unmountChildComponentView:(UIView<RCTComponentViewProtocol> *)childCompo
         childComponentView,
         @(index),
         @([childComponentView.superview tag]));
+    NSArray<UIView *> *containerSubviews = self.currentContainerView.subviews;
+    BOOL isIndexInBounds = index >= 0 && (NSUInteger)index < containerSubviews.count;
     RCTAssert(
-        (self.currentContainerView.subviews.count > index) &&
-            [self.currentContainerView.subviews objectAtIndex:index] == childComponentView,
+        isIndexInBounds && [containerSubviews objectAtIndex:index] == childComponentView,
         @"Attempt to unmount a view which has a different index. (parent: %@, child: %@, index: %@, actual index: %@, tag at index: %@)",
         self,
         childComponentView,
         @(index),
-        @([self.currentContainerView.subviews indexOfObject:childComponentView]),
-        @([[self.currentContainerView.subviews objectAtIndex:index] tag]));
+        @([containerSubviews indexOfObject:childComponentView]),
+        isIndexInBounds ? @([[containerSubviews objectAtIndex:index] tag]) : @"out of bounds");
   }
 
   [childComponentView removeFromSuperview];