From 41eb0a6f8a814b381bd1a6c7b703f3c77f1ca135 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Wed, 3 Sep 2025 10:48:02 +0200
Subject: [PATCH 1/2] test: guard write to proxy client if proxy connection is
 ended

In the testing proxy server for proxy client tests, the proxy
client might have already closed the connection when the upstream
connection fails. In that case, there's no need for the proxy
server to inform the proxy client about the error.
---
 test/common/proxy-server.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/test/common/proxy-server.js b/test/common/proxy-server.js
index 29a4073e13467a..95b638ebe9eac0 100644
--- a/test/common/proxy-server.js
+++ b/test/common/proxy-server.js
@@ -91,8 +91,12 @@ exports.createProxyServer = function(options = {}) {
 
     proxyReq.on('error', (err) => {
       logs.push({ error: err, source: 'proxy request' });
-      res.write('HTTP/1.1 500 Connection Error\r\n\r\n');
-      res.end('Proxy error: ' + err.message);
+      // The proxy client might have already closed the connection
+      // when the upstream connection fails.
+      if (!res.writableEnded) {
+        res.write('HTTP/1.1 500 Connection Error\r\n\r\n');
+        res.end('Proxy error: ' + err.message);
+      }
     });
   });
 

From 096f459aa8b3d4ba354d2a18d4f2df742f9e5ec1 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Sat, 13 Sep 2025 12:31:12 +0200
Subject: [PATCH 2/2] fixup! test: guard write to proxy client if proxy
 connection is ended

---
 ...ttps-proxy-request-invalid-char-in-url.mjs | 26 ++++++++++++-------
 test/common/proxy-server.js                   |  6 ++---
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/test/client-proxy/test-https-proxy-request-invalid-char-in-url.mjs b/test/client-proxy/test-https-proxy-request-invalid-char-in-url.mjs
index 268c43cd2009fb..10b308c3406829 100644
--- a/test/client-proxy/test-https-proxy-request-invalid-char-in-url.mjs
+++ b/test/client-proxy/test-https-proxy-request-invalid-char-in-url.mjs
@@ -21,9 +21,10 @@ const server = https.createServer({
   cert: fixtures.readKey('agent8-cert.pem'),
   key: fixtures.readKey('agent8-key.pem'),
 }, (req, res) => {
+  console.log(`[Upstream server] responding to request for ${inspect(req.url)}`);
   requests.add(`https://localhost:${server.address().port}${req.url}`);
   res.writeHead(200, { 'Content-Type': 'text/plain' });
-  res.end(`Response for ${req.url}`);
+  res.end(`Response for ${inspect(req.url)}`);
 });
 
 server.listen(0);
@@ -54,7 +55,7 @@ https.globalAgent = new https.Agent({
 
 const severHost = `localhost:${server.address().port}`;
 
-let counter = testCases.length;
+let counter = 0;
 const expectedUrls = new Set();
 const expectedProxyLogs = new Set();
 for (const testCase of testCases) {
@@ -69,15 +70,20 @@ for (const testCase of testCases) {
   https.request(url, (res) => {
     res.on('error', common.mustNotCall());
     res.setEncoding('utf8');
-    res.on('data', () => {});
-    res.on('end', common.mustCall(() => {
-      console.log(`#${counter--} eneded response for: ${inspect(url)}`);
+    res.on('data', (data) => {
+      console.log(`[Proxy client] Received response from server for ${inspect(url)}: ${data.toString()}`);
+    });
+    res.on('close', common.mustCall(() => {
+      console.log(`[Proxy client] #${++counter} closed request for: ${inspect(url)}`);
       // Finished all test cases.
-      if (counter === 0) {
-        proxy.close();
-        server.close();
-        assert.deepStrictEqual(requests, expectedUrls);
-        assert.deepStrictEqual(new Set(logs), expectedProxyLogs);
+      if (counter === testCases.length) {
+        setImmediate(() => {
+          console.log('All requests completed, shutting down.');
+          proxy.close();
+          server.close();
+          assert.deepStrictEqual(requests, expectedUrls);
+          assert.deepStrictEqual(new Set(logs), expectedProxyLogs);
+        });
       }
     }));
   }).on('error', common.mustNotCall()).end();
diff --git a/test/common/proxy-server.js b/test/common/proxy-server.js
index 95b638ebe9eac0..5e042decdbc74b 100644
--- a/test/common/proxy-server.js
+++ b/test/common/proxy-server.js
@@ -63,7 +63,7 @@ exports.createProxyServer = function(options = {}) {
     });
 
     res.on('error', (err) => {
-      logs.push({ error: err, source: 'proxy response' });
+      logs.push({ error: err, source: 'client response for request' });
     });
 
     req.pipe(proxyReq, { end: true });
@@ -75,7 +75,7 @@ exports.createProxyServer = function(options = {}) {
     const [hostname, port] = req.url.split(':');
 
     res.on('error', (err) => {
-      logs.push({ error: err, source: 'proxy response' });
+      logs.push({ error: err, source: 'client response for connect' });
     });
 
     const proxyReq = net.connect(port, hostname, () => {
@@ -90,7 +90,7 @@ exports.createProxyServer = function(options = {}) {
     });
 
     proxyReq.on('error', (err) => {
-      logs.push({ error: err, source: 'proxy request' });
+      logs.push({ error: err, source: 'proxy connect' });
       // The proxy client might have already closed the connection
       // when the upstream connection fails.
       if (!res.writableEnded) {