From 2ac649cc4d85056161f06549514bf06655692061 Mon Sep 17 00:00:00 2001
From: Damian Kocjan <DamianoKPL@wp.pl>
Date: Mon, 9 Nov 2026 21:31:52 +0100
Subject: [PATCH] perf: improve useSet operations performance

Instead of converting set objects to array and using array methods (O(n)), we utilize direct set methods (O(1))
---
 src/useSet.ts        | 43 +++++++++++++++++++++++++++++++++++--------
 tests/useSet.test.ts |  4 ++++
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/src/useSet.ts b/src/useSet.ts
index 9c88306cc9..c0c86c3b36 100644
--- a/src/useSet.ts
+++ b/src/useSet.ts
@@ -16,17 +16,44 @@ const useSet = <K>(initialSet = new Set<K>()): [Set<K>, Actions<K>] => {
   const [set, setSet] = useState(initialSet);
 
   const stableActions = useMemo<StableActions<K>>(() => {
-    const add = (item: K) => setSet((prevSet) => new Set([...Array.from(prevSet), item]));
+    const add = (item: K) =>
+      setSet((prevSet) => {
+        if (prevSet.has(item)) return prevSet;
+
+        const newSet = new Set(prevSet);
+        newSet.add(item);
+        return newSet;
+      });
+
     const remove = (item: K) =>
-      setSet((prevSet) => new Set(Array.from(prevSet).filter((i) => i !== item)));
+      setSet((prevSet) => {
+        if (!prevSet.has(item)) return prevSet;
+
+        const newSet = new Set(prevSet);
+        newSet.delete(item);
+        return newSet;
+      });
+
     const toggle = (item: K) =>
-      setSet((prevSet) =>
-        prevSet.has(item)
-          ? new Set(Array.from(prevSet).filter((i) => i !== item))
-          : new Set([...Array.from(prevSet), item])
-      );
+      setSet((prevSet) => {
+        const newSet = new Set(prevSet);
+        if (newSet.has(item)) {
+          newSet.delete(item);
+        } else {
+          newSet.add(item);
+        }
+        return newSet;
+      });
+
+    const reset = () => setSet(initialSet);
+
+    const clear = () =>
+      setSet((prevSet) => {
+        if (prevSet.size === 0) return prevSet;
+        return new Set();
+      });
 
-    return { add, remove, toggle, reset: () => setSet(initialSet), clear: () => setSet(new Set()) };
+    return { add, remove, toggle, reset, clear };
   }, [setSet]);
 
   const utils = {
diff --git a/tests/useSet.test.ts b/tests/useSet.test.ts
index b4daa70d3e..8967fbc575 100644
--- a/tests/useSet.test.ts
+++ b/tests/useSet.test.ts
@@ -76,6 +76,7 @@ it('should add a new key', () => {
 
 it('should work if setting existing key', () => {
   const { result } = setUp(new Set(['oldKey']));
+  const initialSet = result.current[0];
   const [, utils] = result.current;
 
   act(() => {
@@ -83,6 +84,7 @@ it('should work if setting existing key', () => {
   });
 
   expect(result.current[0]).toEqual(new Set(['oldKey']));
+  expect(result.current[0]).toBe(initialSet);
 });
 
 it('should remove existing key', () => {
@@ -120,6 +122,7 @@ it('should add a new key on toggle', () => {
 
 it('should do nothing if removing non-existing key', () => {
   const { result } = setUp(new Set(['a', 'b']));
+  const initialSet = result.current[0];
   const [, utils] = result.current;
 
   act(() => {
@@ -127,6 +130,7 @@ it('should do nothing if removing non-existing key', () => {
   });
 
   expect(result.current[0]).toEqual(new Set(['a', 'b']));
+  expect(result.current[0]).toBe(initialSet);
 });
 
 it('should reset to initial set provided', () => {