doc: add note about clientError writable handling

ShogunPanda · codebytere · commit 318fcf818869 · 2020-06-07T10:15:10.000-07:00
PR-URL: #33308 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
diff --git a/doc/api/http.md b/doc/api/http.md
@@ -1003,6 +1003,21 @@ ensure the response is a properly formatted HTTP response message.
   correctly;
 * `rawPacket`: the raw packet of current request.
 
+In some cases, the client has already received the response and/or the socket
+has already been destroyed, like in case of `ECONNRESET` errors. Before
+trying to send data to the socket, it is better to check that it is still
+writable.
+
+```js
+server.on('clientError', (err, socket) => {
+  if (err.code === 'ECONNRESET' || !socket.writable) {
+    return;
+  }
+
+  socket.end('HTTP/1.1 400 Bad Request\r\n\r\n');
+});
+```
+
 ### Event: `'close'`
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