Handle client aborts and child signals

Detect and handle child process termination by signal in runQoderRequest (return -1 code and append a signal message to stderr). Update chat and completions routes to track real client aborts with req.on('aborted') and a clientAborted flag, guard onDone/onError callbacks to avoid writing after the client disconnected or response ended, and only kill the child process when appropriate. This prevents premature child termination from req "close" events and avoids sending responses after disconnects.

Author: foxy1402

src/helpers/spawn.js

@@ -156,8 +156,12 @@ const runQoderRequest = ({
     addSystem(text, "error", "qodercli-stderr");
   });
 
-  child.on("close", (code) => {
-    settle(() => onDone(code, stderrOutput.trim()));
+  child.on("close", (code, signal) => {
+    const finalCode = code == null && signal ? -1 : code;
+    const finalStderr = signal
+      ? `${stderrOutput.trim()}${stderrOutput.trim() ? "\n" : ""}Process terminated by signal: ${signal}`
+      : stderrOutput.trim();
+    settle(() => onDone(finalCode, finalStderr));
   });
 
   child.on("error", (err) => {

src/routes/chat.js

@@ -138,6 +138,7 @@ router.post("/", (req, res) => {
     // Accumulate full text so we can detect tool calls at the end
     let fullStreamText = "";
 
+    let clientAborted = false;
     const child = runQoderRequest({
       prompt,
       model,
@@ -173,6 +174,7 @@ router.post("/", (req, res) => {
         }
       },
       onDone: (code, stderr) => {
+        if (clientAborted || res.writableEnded) return;
         if (code !== 0) {
           console.error(
             "[chat/completions] qodercli exit code:",
@@ -213,6 +215,7 @@ router.post("/", (req, res) => {
         res.end();
       },
       onError: (err) => {
+        if (clientAborted || res.writableEnded) return;
         console.error("[chat/completions] error:", err.message);
         res.write(
           `data: ${JSON.stringify({ error: { message: err.message, type: err.code === "TIMEOUT" ? "timeout_error" : "api_error" } })}\n\n`,
@@ -221,19 +224,21 @@ router.post("/", (req, res) => {
       },
     });
 
-    req.on("close", () => {
+    req.on("aborted", () => {
+      clientAborted = true;
       console.log(
         "[Stream] Client disconnected at",
         Date.now() - streamStartTime,
         "ms",
       );
-      child.kill();
+      if (!res.writableEnded) child.kill();
     });
   } else {
     // Non-streaming path
     let fullContent = "";
     let finishReason = "stop";
     let allToolCalls = [];
+    let clientAborted = false;
 
     const child = runQoderRequest({
       prompt,
@@ -251,6 +256,7 @@ router.post("/", (req, res) => {
         if (data.message?.stop_reason) finishReason = data.message.stop_reason;
       },
       onDone: (code, stderr) => {
+        if (clientAborted || res.writableEnded) return;
         if (code !== 0) {
           return res.status(500).json({
             error: {
@@ -287,6 +293,7 @@ router.post("/", (req, res) => {
         }
       },
       onError: (err) => {
+        if (clientAborted || res.writableEnded) return;
         res.status(err.code === "TIMEOUT" ? 504 : 500).json({
           error: {
             message: err.message,
@@ -296,9 +303,11 @@ router.post("/", (req, res) => {
       },
     });
 
-    // Clean up if client disconnects during non-streaming response
-    req.on("close", () => {
-      if (!res.headersSent) child.kill();
+    // Clean up only on real client aborts during non-streaming response.
+    // req "close" can fire after normal request completion and would kill too early.
+    req.on("aborted", () => {
+      clientAborted = true;
+      if (!res.writableEnded) child.kill();
     });
   }
 });

src/routes/completions.js

@@ -52,6 +52,7 @@ router.post('/', (req, res) => {
     };
     res.write(`data: ${JSON.stringify(initialChunk)}\n\n`);
 
+    let clientAborted = false;
     const child = runQoderRequest({
       prompt,
       model,
@@ -64,20 +65,26 @@ router.post('/', (req, res) => {
         }
       },
       onDone: (_code, _stderr) => {
+        if (clientAborted || res.writableEnded) return;
         res.write('data: [DONE]\n\n');
         res.end();
       },
       onError: (err) => {
+        if (clientAborted || res.writableEnded) return;
         console.error('[completions]', err.message);
         res.write(`data: ${JSON.stringify({ error: { message: err.message } })}\n\n`);
         res.end();
       },
     });
 
-    req.on('close', () => child.kill());
+    req.on('aborted', () => {
+      clientAborted = true;
+      if (!res.writableEnded) child.kill();
+    });
   } else {
     let fullText = '';
     let finishReason = 'stop';
+    let clientAborted = false;
 
     const child = runQoderRequest({
       prompt,
@@ -89,6 +96,7 @@ router.post('/', (req, res) => {
         if (data.message?.stop_reason) finishReason = data.message.stop_reason;
       },
       onDone: (code, stderr) => {
+        if (clientAborted || res.writableEnded) return;
         if (code !== 0) {
           return res.status(500).json({
             error: { message: `qodercli exited with code ${code}`, type: 'api_error', details: stderr },
@@ -97,14 +105,17 @@ router.post('/', (req, res) => {
         res.json(buildFullCompletionResponse(fullText, model, finishReason, id));
       },
       onError: (err) => {
+        if (clientAborted || res.writableEnded) return;
         res.status(err.code === 'TIMEOUT' ? 504 : 500).json({
           error: { message: err.message, type: err.code === 'TIMEOUT' ? 'timeout_error' : 'api_error' },
         });
       },
     });
 
-    // For non-streaming, don't kill on client disconnect - let it complete  
-    // req.on('close', () => child.kill());
+    req.on('aborted', () => {
+      clientAborted = true;
+      if (!res.writableEnded) child.kill();
+    });
   }
 });