From 135cd7f3830b2c33a2fac7e33bbd513097f7c90f Mon Sep 17 00:00:00 2001
From: Wonsuk Choi <sukvvon@gmail.com>
Date: Fri, 3 Apr 2026 10:10:15 +0900
Subject: [PATCH 1/2] fix(compat/function/debounce): skip 'maxWait' invocation
 when both 'leading' and 'trailing' are 'false'

---
 src/compat/function/debounce.spec.ts | 24 ++++++++++++++++++++++++
 src/compat/function/debounce.ts      |  5 ++++-
 src/compat/function/throttle.spec.ts | 24 ++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/src/compat/function/debounce.spec.ts b/src/compat/function/debounce.spec.ts
index 0817a55543..2042bd37a8 100644
--- a/src/compat/function/debounce.spec.ts
+++ b/src/compat/function/debounce.spec.ts
@@ -559,6 +559,30 @@ describe('debounce', () => {
     expect(callCount).toBe(0);
   });
 
+  it('should not invoke the function with `maxWait` when both `leading` and `trailing` are `false`', async () => {
+    let callCount = 0;
+
+    const debounced = debounce(
+      () => {
+        callCount++;
+      },
+      64,
+      { leading: false, trailing: false, maxWait: 64 }
+    );
+
+    debounced();
+    debounced();
+
+    await delay(96);
+
+    debounced();
+    debounced();
+
+    await delay(96);
+
+    expect(callCount).toBe(0);
+  });
+
   it('should match the type of lodash', () => {
     expectTypeOf(debounce).toEqualTypeOf<typeof debounceLodash>();
   });
diff --git a/src/compat/function/debounce.ts b/src/compat/function/debounce.ts
index 559985b3be..b8248b5ddf 100644
--- a/src/compat/function/debounce.ts
+++ b/src/compat/function/debounce.ts
@@ -198,7 +198,10 @@ export function debounce<F extends (...args: any[]) => any>(
       }
 
       if (Date.now() - pendingAt >= maxWait) {
-        result = func.apply(this, args);
+        if (leading || trailing) {
+          result = func.apply(this, args);
+        }
+
         pendingAt = Date.now();
 
         _debounced.cancel();
diff --git a/src/compat/function/throttle.spec.ts b/src/compat/function/throttle.spec.ts
index 93d05ceb32..41914e5871 100644
--- a/src/compat/function/throttle.spec.ts
+++ b/src/compat/function/throttle.spec.ts
@@ -353,6 +353,30 @@ describe('throttle', () => {
     expectTypeOf(throttle).toEqualTypeOf<typeof throttleLodash>();
   });
 
+  it('should not invoke the function when both `leading` and `trailing` are `false`', async () => {
+    let callCount = 0;
+
+    const throttled = throttle(
+      () => {
+        callCount++;
+      },
+      64,
+      { leading: false, trailing: false }
+    );
+
+    throttled();
+    throttled();
+
+    await delay(96);
+
+    throttled();
+    throttled();
+
+    await delay(96);
+
+    expect(callCount).toBe(0);
+  });
+
   it('should not invoke the function even after flush is called if timer is going', async () => {
     let callCount = 0;
     const throttled = throttle(() => ++callCount, 32);

From 2d6be6612655db4acf378b6b8d1d9ea4ae9c6b86 Mon Sep 17 00:00:00 2001
From: Sojin Park <raon0211@gmail.com>
Date: Mon, 17 Aug 2026 17:08:31 +0900
Subject: [PATCH 2/2] test: update bundle size snapshots

---
 benchmarks/bundle-size/debounce.spec.ts | 2 +-
 benchmarks/bundle-size/throttle.spec.ts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/benchmarks/bundle-size/debounce.spec.ts b/benchmarks/bundle-size/debounce.spec.ts
index ac3dcbbf95..f731126385 100644
--- a/benchmarks/bundle-size/debounce.spec.ts
+++ b/benchmarks/bundle-size/debounce.spec.ts
@@ -14,6 +14,6 @@ describe('debounce bundle size', () => {
 
   it('es-toolkit/compat', async () => {
     const bundleSize = await getBundleSize('es-toolkit/compat', 'debounce');
-    expect(bundleSize).toMatchInlineSnapshot(`961`);
+    expect(bundleSize).toMatchInlineSnapshot(`971`);
   });
 });
diff --git a/benchmarks/bundle-size/throttle.spec.ts b/benchmarks/bundle-size/throttle.spec.ts
index b7e81b7c43..0ea3c5cb24 100644
--- a/benchmarks/bundle-size/throttle.spec.ts
+++ b/benchmarks/bundle-size/throttle.spec.ts
@@ -14,6 +14,6 @@ describe('throttle bundle size', () => {
 
   it('es-toolkit/compat', async () => {
     const bundleSize = await getBundleSize('es-toolkit/compat', 'throttle');
-    expect(bundleSize).toMatchInlineSnapshot(`1065`);
+    expect(bundleSize).toMatchInlineSnapshot(`1075`);
   });
 });