From f5bfda9699e24891ea968edf6c89f27c4ece4e3b Mon Sep 17 00:00:00 2001
From: Jarred Sumner <jarred@jarredsumner.com>
Date: Thu, 29 May 2025 17:05:51 -0700
Subject: [PATCH] Fix http socket encoding check (#20031)

Co-authored-by: Jarred-Sumner <709451+Jarred-Sumner@users.noreply.github.com>
---
 src/js/node/_http_server.ts                   |  6 +++++
 .../test-http-socket-encoding-error.js        | 26 +++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 test/js/node/parallel/test-http-socket-encoding-error.js

diff --git a/src/js/node/_http_server.ts b/src/js/node/_http_server.ts
index edd958d037..b2d6c2aab2 100644
--- a/src/js/node/_http_server.ts
+++ b/src/js/node/_http_server.ts
@@ -1408,6 +1408,12 @@ const NodeHTTPServerSocket = class Socket extends Duplex {
     return this;
   }
 
+  setEncoding(_encoding) {
+    const err = new Error("Changing the socket encoding is not allowed per RFC7230 Section 3.");
+    err.code = "ERR_HTTP_SOCKET_ENCODING";
+    throw err;
+  }
+
   unref() {
     return this;
   }
diff --git a/test/js/node/parallel/test-http-socket-encoding-error.js b/test/js/node/parallel/test-http-socket-encoding-error.js
new file mode 100644
index 0000000000..66893e604c
--- /dev/null
+++ b/test/js/node/parallel/test-http-socket-encoding-error.js
@@ -0,0 +1,26 @@
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+const server = http.createServer().listen(0, connectToServer);
+
+server.on('connection', common.mustCall((socket) => {
+  assert.throws(
+    () => {
+      socket.setEncoding('');
+    },
+    {
+      code: 'ERR_HTTP_SOCKET_ENCODING',
+      name: 'Error',
+      message: 'Changing the socket encoding is not allowed per RFC7230 Section 3.'
+    }
+  );
+
+  socket.end();
+}));
+
+function connectToServer() {
+  const client = new http.Agent().createConnection(this.address().port, () => {
+    client.end();
+  }).on('end', () => server.close());
+}