Fix stack overflow in diff() for large element counts

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", () => {

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;