From b053c449c0c62766394a74ac91424754b94d7dce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=9D=A4MrPork=E2=9D=A4?=
 <5321067+MrPorky@users.noreply.github.com>
Date: Mon, 30 Mar 2026 16:09:15 +0200
Subject: [PATCH 1/2] fix: correct maybeExecuteCount increment and add test for
 AbortSignal cancellation

---
 .changeset/humble-coats-shop.md              |  5 +++++
 packages/pacer/src/async-debouncer.ts        |  2 +-
 packages/pacer/tests/async-debouncer.test.ts | 19 ++++++++++++++++++-
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/humble-coats-shop.md

diff --git a/.changeset/humble-coats-shop.md b/.changeset/humble-coats-shop.md
new file mode 100644
index 000000000..d41bcaf07
--- /dev/null
+++ b/.changeset/humble-coats-shop.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/pacer': patch
+---
+
+Fixed a bug in AsyncDebouncer where getAbortSignal() incorrectly returned null due to an internal execution ID mismatch. Abort signals can now be properly attached to underlying async tasks.
diff --git a/packages/pacer/src/async-debouncer.ts b/packages/pacer/src/async-debouncer.ts
index d24d721a7..faf13db0b 100644
--- a/packages/pacer/src/async-debouncer.ts
+++ b/packages/pacer/src/async-debouncer.ts
@@ -362,7 +362,7 @@ export class AsyncDebouncer<TFn extends AnyAsyncFunction> {
     ...args: Parameters<TFn>
   ): Promise<ReturnType<TFn> | undefined> => {
     if (!this.#getEnabled()) return undefined
-    const currentMaybeExecuteCount = this.store.state.maybeExecuteCount + 1
+    const currentMaybeExecuteCount = this.store.state.maybeExecuteCount
 
     try {
       this.#setState({ isExecuting: true })
diff --git a/packages/pacer/tests/async-debouncer.test.ts b/packages/pacer/tests/async-debouncer.test.ts
index 66ac0ca99..06fe1f71f 100644
--- a/packages/pacer/tests/async-debouncer.test.ts
+++ b/packages/pacer/tests/async-debouncer.test.ts
@@ -1,4 +1,4 @@
-import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi, } from 'vitest'
 import { AsyncDebouncer, asyncDebounce } from '../src/async-debouncer'
 
 describe('AsyncDebouncer', () => {
@@ -1358,5 +1358,22 @@ describe('asyncDebounce helper function', () => {
       expect(typeof debouncer.getAbortSignal).toBe('function')
       expect(debouncer.getAbortSignal()).toBeNull()
     })
+
+    it('should return an AbortSignal that can be used to cancel execution', async () => {
+      const debouncer = new AsyncDebouncer(
+        async () => {
+          const signal = debouncer.getAbortSignal()
+          expect(signal).toBeInstanceOf(AbortSignal)
+          return 'result'
+        },
+        { wait: 300 },
+      )
+
+      debouncer.maybeExecute()
+      vi.advanceTimersByTime(150)
+      const promise = debouncer.maybeExecute()
+      vi.advanceTimersByTime(300)
+      await promise
+    })
   })
 })

From 3e3b7e152f5412492be4fa91899b979ba61f537a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=9D=A4MrPork=E2=9D=A4?=
 <5321067+MrPorky@users.noreply.github.com>
Date: Tue, 31 Mar 2026 08:41:35 +0200
Subject: [PATCH 2/2] fix: update AbortSignal test to verify aborted state on
 cancel

---
 packages/pacer/tests/async-debouncer.test.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/pacer/tests/async-debouncer.test.ts b/packages/pacer/tests/async-debouncer.test.ts
index 06fe1f71f..a5f6a31c9 100644
--- a/packages/pacer/tests/async-debouncer.test.ts
+++ b/packages/pacer/tests/async-debouncer.test.ts
@@ -1359,20 +1359,25 @@ describe('asyncDebounce helper function', () => {
       expect(debouncer.getAbortSignal()).toBeNull()
     })
 
-    it('should return an AbortSignal that can be used to cancel execution', async () => {
+
+    it('should return an AbortSignal and mark it aborted when abort() is called', async () => {
       const debouncer = new AsyncDebouncer(
         async () => {
           const signal = debouncer.getAbortSignal()
           expect(signal).toBeInstanceOf(AbortSignal)
+          expect(signal?.aborted).toBe(false)
           return 'result'
         },
         { wait: 300 },
       )
 
+
       debouncer.maybeExecute()
       vi.advanceTimersByTime(150)
       const promise = debouncer.maybeExecute()
       vi.advanceTimersByTime(300)
+      debouncer.abort()
+      expect(debouncer.getAbortSignal()?.aborted ?? true).toBe(true)
       await promise
     })
   })