From cd05d444c3c52e2240252e4df83b94833fe5f46b Mon Sep 17 00:00:00 2001
From: Kalle <38327916+Sendouc@users.noreply.github.com>
Date: Sat, 20 Jun 2026 14:44:28 +0300
Subject: [PATCH] Fix stack overflow in diff() for large element counts

---
 app/utils/arrays.test.ts | 6 ++++++
 app/utils/arrays.ts      | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/app/utils/arrays.test.ts b/app/utils/arrays.test.ts
index 6140d042c..d6a06e67a 100644
--- a/app/utils/arrays.test.ts
+++ b/app/utils/arrays.test.ts
@@ -36,6 +36,12 @@ describe("diff", () => {
 		const result = diff(arr1, arr2);
 		expect(result).toEqual([]);
 	});
+
+	it("should not overflow the stack for very large counts", () => {
+		const arr2 = new Array(200_000).fill(1);
+		const result = diff([], arr2);
+		expect(result).toHaveLength(200_000);
+	});
 });
 
 describe("mostPopularArrayElement", () => {
diff --git a/app/utils/arrays.ts b/app/utils/arrays.ts
index b0444e5ec..a206936a7 100644
--- a/app/utils/arrays.ts
+++ b/app/utils/arrays.ts
@@ -53,7 +53,9 @@ export function diff<T extends string | number>(arr1: T[], arr2: T[]): T[] {
 	const result: T[] = [];
 
 	for (const [element, count] of diff) {
-		result.push(...new Array(count).fill(element));
+		for (let i = 0; i < count; i++) {
+			result.push(element);
+		}
 	}
 
 	return result;