From 7e34c4156200dde204703ee51c9cb095fc40e110 Mon Sep 17 00:00:00 2001
From: Khongchai <world1955@hotmail.com>
Date: Thu, 29 Jan 2026 21:59:22 +0700
Subject: [PATCH] Checking signal abort status before doing anything else

---
 src/fetch.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/fetch.ts b/src/fetch.ts
index 162ea45..d3dc106 100644
--- a/src/fetch.ts
+++ b/src/fetch.ts
@@ -64,6 +64,10 @@ export function fetchEventSource(input: RequestInfo, {
     fetch: inputFetch,
     ...rest
 }: FetchEventSourceInit) {
+    // Request leak if input signal aborted before the subscription even started.
+    if (inputSignal?.aborted) {
+        return;
+    }
     return new Promise<void>((resolve, reject) => {
         // make a copy of the input headers since we may modify it below:
         const headers = { ...inputHeaders };