From a3d9f1371b12844e39751d61f3d4692dd8516a97 Mon Sep 17 00:00:00 2001
From: Abhishek Mehandiratta <36722596+abhi12299@users.noreply.github.com>
Date: Tue, 27 Feb 2024 09:27:06 +0530
Subject: [PATCH] fix(sse): Handler stuck when awaiting aborted SSE stream
 (#2273)

* cancel internal stream reader on responseReadable abort

* run denoify
---
 deno_dist/utils/stream.ts | 7 +++++++
 src/utils/stream.ts       | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/deno_dist/utils/stream.ts b/deno_dist/utils/stream.ts
index 7dfd4e4e5..52a8a5d89 100644
--- a/deno_dist/utils/stream.ts
+++ b/deno_dist/utils/stream.ts
@@ -12,6 +12,13 @@ export class StreamingApi {
 
     const reader = _readable.getReader()
 
+    // in case the user disconnects, let the reader know to cancel
+    // this in-turn results in responseReadable being closed
+    // and writeSSE method no longer blocks indefinitely
+    this.abortSubscribers.push(async () => {
+      await reader.cancel()
+    })
+
     this.responseReadable = new ReadableStream({
       async pull(controller) {
         const { done, value } = await reader.read()
diff --git a/src/utils/stream.ts b/src/utils/stream.ts
index 7dfd4e4e5..52a8a5d89 100644
--- a/src/utils/stream.ts
+++ b/src/utils/stream.ts
@@ -12,6 +12,13 @@ export class StreamingApi {
 
     const reader = _readable.getReader()
 
+    // in case the user disconnects, let the reader know to cancel
+    // this in-turn results in responseReadable being closed
+    // and writeSSE method no longer blocks indefinitely
+    this.abortSubscribers.push(async () => {
+      await reader.cancel()
+    })
+
     this.responseReadable = new ReadableStream({
       async pull(controller) {
         const { done, value } = await reader.read()