http: set default timeout in agent keepSocketAlive

Previous location of setting the timeout would override behaviour of custom HttpAgents' keepSocketAlive. Moving it into the default keepSocketAlive allows it to interoperate with custom agents.

Fixes: nodejs/node#33111

lib/_http_agent.js

@@ -138,11 +138,6 @@ function Agent(options) {
     socket._httpMessage = null;
     this.removeSocket(socket, options);
 
-    const agentTimeout = this.options.timeout || 0;
-    if (socket.timeout !== agentTimeout) {
-      socket.setTimeout(agentTimeout);
-    }
-
     socket.once('error', freeSocketErrorListener);
     freeSockets.push(socket);
   });
@@ -402,6 +397,11 @@ Agent.prototype.keepSocketAlive = function keepSocketAlive(socket) {
   socket.setKeepAlive(true, this.keepAliveMsecs);
   socket.unref();
 
+  const agentTimeout = this.options.timeout || 0;
+  if (socket.timeout !== agentTimeout) {
+    socket.setTimeout(agentTimeout);
+  }
+
   return true;
 };
 

test/parallel/test-http-agent-timeout.js

@@ -92,3 +92,43 @@ const http = require('http');
       }));
   }));
 }
+
+{
+  // Ensure custom keepSocketAlive timeout is respected
+
+  const CUSTOM_TIMEOUT = 60;
+  const AGENT_TIMEOUT = 50;
+
+  class CustomAgent extends http.Agent {
+    keepSocketAlive(socket) {
+      if (!super.keepSocketAlive(socket)) {
+        return false;
+      }
+
+      socket.setTimeout(CUSTOM_TIMEOUT);
+      return true;
+    }
+  }
+
+  const agent = new CustomAgent({ keepAlive: true, timeout: AGENT_TIMEOUT });
+
+  const server = http.createServer((req, res) => {
+    res.end();
+  });
+
+  server.listen(0, common.mustCall(() => {
+    http.get({ port: server.address().port, agent })
+      .on('response', common.mustCall((res) => {
+        const socket = res.socket;
+        assert(socket);
+        res.resume();
+        socket.on('free', common.mustCall(() => {
+          socket.on('timeout', common.mustCall(() => {
+            assert.strictEqual(socket.timeout, CUSTOM_TIMEOUT);
+            agent.destroy();
+            server.close();
+          }));
+        }));
+      }));
+  }));
+}