From c78e6bac0355ae4f7a90f0c694b8fc31ef574ce2 Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 09:54:22 -0400
Subject: [PATCH 1/6] debug: add server+client logging to trace Windows
 disconnect

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/client/index.ts     |  8 +++++++-
 src/pty/bun.ts          | 13 ++++++++++++-
 src/server/websocket.ts | 22 +++++++++++++++++++---
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/src/client/index.ts b/src/client/index.ts
index b5d7649..36c607f 100644
--- a/src/client/index.ts
+++ b/src/client/index.ts
@@ -99,6 +99,7 @@ let ws: WebSocket;
 
 function connect(): void {
   const wsUrl = `${protocol}//${window.location.host}/ws/${sessionId}?cols=${term.cols}&rows=${term.rows}`;
+  console.log(`[webtty] connecting to ${wsUrl}`);
   ws = new WebSocket(wsUrl);
 
   const DIM = '\x1b[2m',
@@ -109,15 +110,19 @@ function connect(): void {
   const msg = (text: string): string => `\r\n${tag} ${DIM}${ITALIC}${text}${RESET}\r\n`;
 
   ws.onopen = () => {
+    console.log(`[webtty] ws open cols=${term.cols} rows=${term.rows}`);
     ws.send(JSON.stringify({ type: 'resize', cols: term.cols, rows: term.rows }));
   };
 
+  let msgCount = 0;
   ws.onmessage = (event: MessageEvent<string>) => {
+    if (msgCount++ < 5) console.log(`[webtty] ws message #${msgCount} ${event.data.length}B`);
     applyDecscusr(term, event.data);
     term.write(event.data);
   };
 
   ws.onclose = (event: CloseEvent) => {
+    console.log(`[webtty] ws close code=${event.code} reason="${event.reason}" wasClean=${event.wasClean}`);
     if (event.code === 4001) {
       term.write(msg('Session removed.'));
       setTimeout(() => window.close(), 500);
@@ -132,7 +137,8 @@ function connect(): void {
     setTimeout(connect, 2000);
   };
 
-  ws.onerror = () => {
+  ws.onerror = (event: Event) => {
+    console.log(`[webtty] ws error`, event);
     term.write(msg('WebSocket error.'));
   };
 }
diff --git a/src/pty/bun.ts b/src/pty/bun.ts
index cf5ced7..81cc711 100644
--- a/src/pty/bun.ts
+++ b/src/pty/bun.ts
@@ -20,20 +20,28 @@ export function spawn(
 ): PtyProcess {
   let onDataCb: ((data: string) => void) | undefined;
   let onExitCb: ((e: { exitCode: number }) => void) | undefined;
+  let dataCount = 0;
+
+  console.log(`[pty:bun] spawn shell=${shell} cols=${cols} rows=${rows} cwd=${homedir()}`);
 
   const proc = Bun.spawn([shell], {
     terminal: {
       cols,
       rows,
       data(_term: unknown, data: Uint8Array) {
-        onDataCb?.(Buffer.from(data).toString('utf8'));
+        const str = Buffer.from(data).toString('utf8');
+        if (dataCount++ < 5) console.log(`[pty:bun] data #${dataCount} ${str.length}B`);
+        onDataCb?.(str);
       },
     },
     cwd: homedir(),
     env: { ...process.env, TERM: term, COLORTERM: colorTerm },
   });
 
+  console.log(`[pty:bun] spawned pid=${proc.pid} terminal=${proc.terminal != null ? 'ok' : 'NULL'}`);
+
   proc.exited.then((exitCode) => {
+    console.log(`[pty:bun] pid=${proc.pid} exited exitCode=${exitCode}`);
     onExitCb?.({ exitCode: exitCode ?? 0 });
   });
 
@@ -46,12 +54,15 @@ export function spawn(
       onExitCb = cb;
     },
     write(data) {
+      console.log(`[pty:bun] write ${JSON.stringify(data.slice(0, 40))}`);
       proc.terminal?.write(data);
     },
     resize(cols, rows) {
+      console.log(`[pty:bun] resize cols=${cols} rows=${rows}`);
       proc.terminal?.resize(cols, rows);
     },
     kill() {
+      console.log(`[pty:bun] kill pid=${proc.pid}`);
       proc.kill();
     },
   };
diff --git a/src/server/websocket.ts b/src/server/websocket.ts
index b787c25..ee06dd4 100644
--- a/src/server/websocket.ts
+++ b/src/server/websocket.ts
@@ -99,17 +99,21 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
 
   httpServer.on('upgrade', (req, socket, head) => {
     const url = new URL(req.url ?? '/', `http://${req.headers.host ?? '127.0.0.1'}`);
+    console.log(`[ws] upgrade request: ${req.url}`);
     if (url.pathname.match(/^\/ws\/([^/]+)$/)) {
       wss.handleUpgrade(req, socket, head, (ws) => wss.emit('connection', ws, req));
     } else {
+      console.log(`[ws] upgrade rejected (bad path): ${url.pathname}`);
       socket.destroy();
     }
   });
 
   wss.on('connection', (ws: WS, req: http.IncomingMessage) => {
     const url = new URL(req.url ?? '/', `http://${req.headers.host ?? '127.0.0.1'}`);
+    console.log(`[ws] connection: ${req.url}`);
     const wsMatch = url.pathname.match(/^\/ws\/([^/]+)$/);
     if (!wsMatch) {
+      console.log(`[ws] closing: no path match`);
       ws.close();
       return;
     }
@@ -118,6 +122,7 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
     try {
       id = decodeURIComponent(wsMatch[1]);
     } catch {
+      console.log(`[ws] closing: bad session id`);
       ws.close(WS_CLOSE.BAD_REQUEST, 'Bad Request');
       return;
     }
@@ -130,22 +135,28 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
       Math.min(500, Number.parseInt(url.searchParams.get('rows') ?? '24', 10) || 24),
     );
 
+    console.log(`[ws] session id="${id}" cols=${cols} rows=${rows} registry_has=${sessionRegistry.has(id)}`);
     if (!sessionRegistry.has(id)) {
+      console.log(`[ws] closing 4001: session not in registry`);
       ws.close(WS_CLOSE.SESSION_GONE, 'session deleted');
       return;
     }
 
     const session = sessionRegistry.get(id);
     if (!session) {
+      console.log(`[ws] closing 4001: session get returned undefined`);
       ws.close(WS_CLOSE.SESSION_GONE, 'session deleted');
       return;
     }
     session.clients.add(ws);
     setLastUsedId(id);
+    console.log(`[ws] session found hasPty=${session.pty != null} clients=${session.clients.size}`);
 
     if (!session.pty) {
       const config = loadConfig();
+      console.log(`[ws] spawning PTY shell=${config.shell}`);
       session.pty = spawnForSession(cols, rows, config.shell, config.term, config.colorTerm);
+      console.log(`[ws] PTY spawned pid=${session.pty.pid}`);
 
       session.pty.onData((data: string) => {
         session.scrollback = (session.scrollback + data).slice(-config.scrollback);
@@ -156,10 +167,12 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
         }
       });
 
-      session.pty.onExit(() => {
+      session.pty.onExit(({ exitCode }) => {
+        console.log(`[ws] PTY exited exitCode=${exitCode} session="${session.id}" clients=${session.clients.size}`);
         sessionRegistry.delete(session.id);
         for (const client of session.clients) {
           if (client.readyState === client.OPEN) {
+            console.log(`[ws] closing client 4001 (shell exited)`);
             client.close(WS_CLOSE.SESSION_GONE, 'shell exited');
           }
         }
@@ -196,11 +209,14 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
       session.pty?.write(message);
     });
 
-    ws.on('close', () => {
+    ws.on('close', (code: number, reason: Buffer) => {
+      console.log(`[ws] client disconnected code=${code} reason="${reason.toString()}" session="${id}"`);
       session.clients.delete(ws);
     });
 
-    ws.on('error', () => {});
+    ws.on('error', (err: Error) => {
+      console.log(`[ws] client error: ${err.message}`);
+    });
   });
 
   return wss;

From d66eff1148206049a42808545baa41f49f33d20b Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 15:26:03 -0400
Subject: [PATCH 2/6] fix: spawn server with node on Windows to avoid Bun PTY
 incompatibility

On Windows, two Bun-specific PTY paths fail:
- Bun.spawn({ terminal }) throws "not supported on this platform"
- @lydell/node-pty's ConPTY backend uses net.Socket({ fd }) to wrap named
  pipes, which Bun's net.Socket implementation does not support on Windows,
  causing pid=0 and ERR_SOCKET_CLOSED on the first write

bunx webtty already works because its #!/usr/bin/env node shim runs the
server with Node.js, where node-pty's ConPTY backend works correctly.
Mirror that explicitly in startServer: on Windows under Bun, spawn the
server process with `node` instead of process.execPath.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cli/http.ts         |  9 ++++++++-
 src/client/index.ts     |  8 +-------
 src/pty/bun.ts          | 13 +------------
 src/server/websocket.ts | 22 +++-------------------
 4 files changed, 13 insertions(+), 39 deletions(-)

diff --git a/src/cli/http.ts b/src/cli/http.ts
index 06ae6af..4e796df 100644
--- a/src/cli/http.ts
+++ b/src/cli/http.ts
@@ -56,7 +56,14 @@ export async function startServer(timeoutMs = 10000, _spawn = childProcess.spawn
     stdio = ['ignore', logFd, logFd];
   }
 
-  const child = _spawn(process.execPath, [serverEntry], {
+  // On Windows, Bun's net.Socket doesn't support the fd-based named-pipe
+  // wrapping that node-pty's ConPTY backend requires, so node-pty fails under
+  // Bun on Windows. bunx works because its #!/usr/bin/env node shim runs the
+  // server with Node.js instead. Mirror that here explicitly.
+  const serverExec =
+    process.platform === 'win32' && process.versions.bun ? 'node' : process.execPath;
+
+  const child = _spawn(serverExec, [serverEntry], {
     detached: true,
     stdio,
     env: { ...process.env, PORT: String(PORT) },
diff --git a/src/client/index.ts b/src/client/index.ts
index 36c607f..b5d7649 100644
--- a/src/client/index.ts
+++ b/src/client/index.ts
@@ -99,7 +99,6 @@ let ws: WebSocket;
 
 function connect(): void {
   const wsUrl = `${protocol}//${window.location.host}/ws/${sessionId}?cols=${term.cols}&rows=${term.rows}`;
-  console.log(`[webtty] connecting to ${wsUrl}`);
   ws = new WebSocket(wsUrl);
 
   const DIM = '\x1b[2m',
@@ -110,19 +109,15 @@ function connect(): void {
   const msg = (text: string): string => `\r\n${tag} ${DIM}${ITALIC}${text}${RESET}\r\n`;
 
   ws.onopen = () => {
-    console.log(`[webtty] ws open cols=${term.cols} rows=${term.rows}`);
     ws.send(JSON.stringify({ type: 'resize', cols: term.cols, rows: term.rows }));
   };
 
-  let msgCount = 0;
   ws.onmessage = (event: MessageEvent<string>) => {
-    if (msgCount++ < 5) console.log(`[webtty] ws message #${msgCount} ${event.data.length}B`);
     applyDecscusr(term, event.data);
     term.write(event.data);
   };
 
   ws.onclose = (event: CloseEvent) => {
-    console.log(`[webtty] ws close code=${event.code} reason="${event.reason}" wasClean=${event.wasClean}`);
     if (event.code === 4001) {
       term.write(msg('Session removed.'));
       setTimeout(() => window.close(), 500);
@@ -137,8 +132,7 @@ function connect(): void {
     setTimeout(connect, 2000);
   };
 
-  ws.onerror = (event: Event) => {
-    console.log(`[webtty] ws error`, event);
+  ws.onerror = () => {
     term.write(msg('WebSocket error.'));
   };
 }
diff --git a/src/pty/bun.ts b/src/pty/bun.ts
index 81cc711..cf5ced7 100644
--- a/src/pty/bun.ts
+++ b/src/pty/bun.ts
@@ -20,28 +20,20 @@ export function spawn(
 ): PtyProcess {
   let onDataCb: ((data: string) => void) | undefined;
   let onExitCb: ((e: { exitCode: number }) => void) | undefined;
-  let dataCount = 0;
-
-  console.log(`[pty:bun] spawn shell=${shell} cols=${cols} rows=${rows} cwd=${homedir()}`);
 
   const proc = Bun.spawn([shell], {
     terminal: {
       cols,
       rows,
       data(_term: unknown, data: Uint8Array) {
-        const str = Buffer.from(data).toString('utf8');
-        if (dataCount++ < 5) console.log(`[pty:bun] data #${dataCount} ${str.length}B`);
-        onDataCb?.(str);
+        onDataCb?.(Buffer.from(data).toString('utf8'));
       },
     },
     cwd: homedir(),
     env: { ...process.env, TERM: term, COLORTERM: colorTerm },
   });
 
-  console.log(`[pty:bun] spawned pid=${proc.pid} terminal=${proc.terminal != null ? 'ok' : 'NULL'}`);
-
   proc.exited.then((exitCode) => {
-    console.log(`[pty:bun] pid=${proc.pid} exited exitCode=${exitCode}`);
     onExitCb?.({ exitCode: exitCode ?? 0 });
   });
 
@@ -54,15 +46,12 @@ export function spawn(
       onExitCb = cb;
     },
     write(data) {
-      console.log(`[pty:bun] write ${JSON.stringify(data.slice(0, 40))}`);
       proc.terminal?.write(data);
     },
     resize(cols, rows) {
-      console.log(`[pty:bun] resize cols=${cols} rows=${rows}`);
       proc.terminal?.resize(cols, rows);
     },
     kill() {
-      console.log(`[pty:bun] kill pid=${proc.pid}`);
       proc.kill();
     },
   };
diff --git a/src/server/websocket.ts b/src/server/websocket.ts
index ee06dd4..b787c25 100644
--- a/src/server/websocket.ts
+++ b/src/server/websocket.ts
@@ -99,21 +99,17 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
 
   httpServer.on('upgrade', (req, socket, head) => {
     const url = new URL(req.url ?? '/', `http://${req.headers.host ?? '127.0.0.1'}`);
-    console.log(`[ws] upgrade request: ${req.url}`);
     if (url.pathname.match(/^\/ws\/([^/]+)$/)) {
       wss.handleUpgrade(req, socket, head, (ws) => wss.emit('connection', ws, req));
     } else {
-      console.log(`[ws] upgrade rejected (bad path): ${url.pathname}`);
       socket.destroy();
     }
   });
 
   wss.on('connection', (ws: WS, req: http.IncomingMessage) => {
     const url = new URL(req.url ?? '/', `http://${req.headers.host ?? '127.0.0.1'}`);
-    console.log(`[ws] connection: ${req.url}`);
     const wsMatch = url.pathname.match(/^\/ws\/([^/]+)$/);
     if (!wsMatch) {
-      console.log(`[ws] closing: no path match`);
       ws.close();
       return;
     }
@@ -122,7 +118,6 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
     try {
       id = decodeURIComponent(wsMatch[1]);
     } catch {
-      console.log(`[ws] closing: bad session id`);
       ws.close(WS_CLOSE.BAD_REQUEST, 'Bad Request');
       return;
     }
@@ -135,28 +130,22 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
       Math.min(500, Number.parseInt(url.searchParams.get('rows') ?? '24', 10) || 24),
     );
 
-    console.log(`[ws] session id="${id}" cols=${cols} rows=${rows} registry_has=${sessionRegistry.has(id)}`);
     if (!sessionRegistry.has(id)) {
-      console.log(`[ws] closing 4001: session not in registry`);
       ws.close(WS_CLOSE.SESSION_GONE, 'session deleted');
       return;
     }
 
     const session = sessionRegistry.get(id);
     if (!session) {
-      console.log(`[ws] closing 4001: session get returned undefined`);
       ws.close(WS_CLOSE.SESSION_GONE, 'session deleted');
       return;
     }
     session.clients.add(ws);
     setLastUsedId(id);
-    console.log(`[ws] session found hasPty=${session.pty != null} clients=${session.clients.size}`);
 
     if (!session.pty) {
       const config = loadConfig();
-      console.log(`[ws] spawning PTY shell=${config.shell}`);
       session.pty = spawnForSession(cols, rows, config.shell, config.term, config.colorTerm);
-      console.log(`[ws] PTY spawned pid=${session.pty.pid}`);
 
       session.pty.onData((data: string) => {
         session.scrollback = (session.scrollback + data).slice(-config.scrollback);
@@ -167,12 +156,10 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
         }
       });
 
-      session.pty.onExit(({ exitCode }) => {
-        console.log(`[ws] PTY exited exitCode=${exitCode} session="${session.id}" clients=${session.clients.size}`);
+      session.pty.onExit(() => {
         sessionRegistry.delete(session.id);
         for (const client of session.clients) {
           if (client.readyState === client.OPEN) {
-            console.log(`[ws] closing client 4001 (shell exited)`);
             client.close(WS_CLOSE.SESSION_GONE, 'shell exited');
           }
         }
@@ -209,14 +196,11 @@ export function createWebSocketServer(httpServer: http.Server): WebSocketServer
       session.pty?.write(message);
     });
 
-    ws.on('close', (code: number, reason: Buffer) => {
-      console.log(`[ws] client disconnected code=${code} reason="${reason.toString()}" session="${id}"`);
+    ws.on('close', () => {
       session.clients.delete(ws);
     });
 
-    ws.on('error', (err: Error) => {
-      console.log(`[ws] client error: ${err.message}`);
-    });
+    ws.on('error', () => {});
   });
 
   return wss;

From fdade4717c9edab5c04a0ec8cd9cbd03116ca678 Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 21:59:04 -0400
Subject: [PATCH 3/6] =?UTF-8?q?fix:=20address=20code=20review=20=E2=80=94?=
 =?UTF-8?q?=20.ts=20entry=20guard=20and=20spawn=20error=20handling?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- When serverExec is `node`, always resolve to the compiled `.js` entry
  since Node.js cannot execute `.ts` files directly (unlike Bun)
- Add a spawn `error` event handler so a missing `node` binary on PATH
  surfaces immediately with a clear message rather than timing out

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cli/http.ts | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/cli/http.ts b/src/cli/http.ts
index 4e796df..d63d477 100644
--- a/src/cli/http.ts
+++ b/src/cli/http.ts
@@ -39,7 +39,18 @@ export async function isServerRunning(): Promise<boolean> {
  */
 export async function startServer(timeoutMs = 10000, _spawn = childProcess.spawn): Promise<void> {
   const isBun = typeof (globalThis as Record<string, unknown>).Bun !== 'undefined';
-  const isTs = isBun && __filename.endsWith('.ts');
+
+  // On Windows, Bun's net.Socket doesn't support the fd-based named-pipe
+  // wrapping that node-pty's ConPTY backend requires, so node-pty fails under
+  // Bun on Windows. bunx works because its #!/usr/bin/env node shim runs the
+  // server with Node.js instead. Mirror that here explicitly.
+  const useNode = process.platform === 'win32' && isBun;
+  const serverExec = useNode ? 'node' : process.execPath;
+
+  // When the executor is Node.js it cannot run .ts files directly, so always
+  // resolve to the compiled .js entry regardless of whether the CLI itself is
+  // running from source.
+  const isTs = isBun && !useNode && __filename.endsWith('.ts');
   const serverEntry = path.resolve(__dirname, isTs ? '../server/index.ts' : '../server/index.js');
   if (!fs.existsSync(serverEntry)) {
     console.error(`webtty: server entry not found at ${serverEntry}`);
@@ -56,18 +67,16 @@ export async function startServer(timeoutMs = 10000, _spawn = childProcess.spawn
     stdio = ['ignore', logFd, logFd];
   }
 
-  // On Windows, Bun's net.Socket doesn't support the fd-based named-pipe
-  // wrapping that node-pty's ConPTY backend requires, so node-pty fails under
-  // Bun on Windows. bunx works because its #!/usr/bin/env node shim runs the
-  // server with Node.js instead. Mirror that here explicitly.
-  const serverExec =
-    process.platform === 'win32' && process.versions.bun ? 'node' : process.execPath;
-
   const child = _spawn(serverExec, [serverEntry], {
     detached: true,
     stdio,
     env: { ...process.env, PORT: String(PORT) },
   });
+  child.on('error', (err) => {
+    const hint = useNode ? ' (Node.js must be on PATH when running webtty under Bun on Windows)' : '';
+    console.error(`webtty: failed to start server: ${err.message}${hint}`);
+    process.exit(1);
+  });
   child.unref();
   if (logFd !== undefined) fs.closeSync(logFd);
 

From 70df063dc98d970001096116b4526bfa7c7d46a1 Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 23:05:37 -0400
Subject: [PATCH 4/6] fix: update tests for child.on and address pre-existing
 lint warnings

- Add `on` method to fakeChild mocks in http.test.ts so startServer's
  new spawn error handler doesn't throw in tests
- Cast process.exit to void-return type before the early return so the
  'server entry not found' test path exits cleanly when exit is mocked
- Replace noNonNullAssertion (session!) with optional chaining (session?)
  in websocket.test.ts to clear pre-existing biome lint warnings

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cli/http.test.ts         | 6 +++---
 src/cli/http.ts              | 3 ++-
 src/server/websocket.test.ts | 4 ++--
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/cli/http.test.ts b/src/cli/http.test.ts
index 7d013fc..ed1f765 100644
--- a/src/cli/http.test.ts
+++ b/src/cli/http.test.ts
@@ -101,7 +101,7 @@ describe('startServer', () => {
     const mkdirSpy = spyOn(fs, 'mkdirSync').mockImplementation(() => undefined);
     const openSpy = spyOn(fs, 'openSync').mockReturnValue(99);
     const closeSpy = spyOn(fs, 'closeSync').mockImplementation(() => {});
-    const fakeChild = { unref: mock(() => {}) };
+    const fakeChild = { unref: mock(() => {}), on: mock(() => {}) };
     const spawnMock = mock(() => fakeChild);
 
     globalThis.fetch = mock(
@@ -152,7 +152,7 @@ describe('startServer', () => {
 
   test('spawns server and resolves when it becomes reachable', async () => {
     const existsSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
-    const fakeChild = { unref: mock(() => {}) };
+    const fakeChild = { unref: mock(() => {}), on: mock(() => {}) };
     const spawnMock = mock(() => fakeChild);
 
     let calls = 0;
@@ -173,7 +173,7 @@ describe('startServer', () => {
 
   test('exits with error when server does not start within timeout', async () => {
     const existsSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
-    const spawnMock = mock(() => ({ unref: () => {} }));
+    const spawnMock = mock(() => ({ unref: () => {}, on: () => {} }));
     const exitSpy = spyOn(process, 'exit').mockImplementation((() => {}) as () => never);
     const errorSpy = spyOn(console, 'error').mockImplementation(() => {});
 
diff --git a/src/cli/http.ts b/src/cli/http.ts
index d63d477..1d19da9 100644
--- a/src/cli/http.ts
+++ b/src/cli/http.ts
@@ -54,7 +54,8 @@ export async function startServer(timeoutMs = 10000, _spawn = childProcess.spawn
   const serverEntry = path.resolve(__dirname, isTs ? '../server/index.ts' : '../server/index.js');
   if (!fs.existsSync(serverEntry)) {
     console.error(`webtty: server entry not found at ${serverEntry}`);
-    process.exit(1);
+    (process.exit as (code?: number) => void)(1);
+    return;
   }
 
   const config = loadConfig();
diff --git a/src/server/websocket.test.ts b/src/server/websocket.test.ts
index e6c1202..0d641bc 100644
--- a/src/server/websocket.test.ts
+++ b/src/server/websocket.test.ts
@@ -221,9 +221,9 @@ describe('websocket', () => {
     }>;
     const session = sessions.find((s) => s.id === 'ws-test-pid-route');
     expect(session).toBeDefined();
-    expect(typeof session!.pid).toBe('number');
+    expect(typeof session?.pid).toBe('number');
 
-    const res = await fetch(`${baseUrl}/p/${session!.pid}`, { redirect: 'manual' });
+    const res = await fetch(`${baseUrl}/p/${session?.pid}`, { redirect: 'manual' });
     expect(res.status).toBe(302);
     expect(res.headers.get('location')).toBe('/s/ws-test-pid-route');
   });

From 14479590b723c6f706ea170340d73fe21b7d3496 Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 23:09:43 -0400
Subject: [PATCH 5/6] fix: split long ternary in http.ts to satisfy biome
 100-char line limit

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cli/http.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/cli/http.ts b/src/cli/http.ts
index 1d19da9..2f4d24b 100644
--- a/src/cli/http.ts
+++ b/src/cli/http.ts
@@ -74,7 +74,9 @@ export async function startServer(timeoutMs = 10000, _spawn = childProcess.spawn
     env: { ...process.env, PORT: String(PORT) },
   });
   child.on('error', (err) => {
-    const hint = useNode ? ' (Node.js must be on PATH when running webtty under Bun on Windows)' : '';
+    const hint = useNode
+      ? ' (Node.js must be on PATH when running webtty under Bun on Windows)'
+      : '';
     console.error(`webtty: failed to start server: ${err.message}${hint}`);
     process.exit(1);
   });

From 6c1415a10a9989b0e352ce25d702bea5328048ad Mon Sep 17 00:00:00 2001
From: jesse23 <wenjia.peng@siemens.com>
Date: Tue, 21 Apr 2026 23:13:04 -0400
Subject: [PATCH 6/6] fix: mock loadConfig in startServer tests to avoid real
 fs reads in CI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cli/http.test.ts | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/cli/http.test.ts b/src/cli/http.test.ts
index ed1f765..617e6a0 100644
--- a/src/cli/http.test.ts
+++ b/src/cli/http.test.ts
@@ -162,6 +162,11 @@ describe('startServer', () => {
       return new Response('[]', { status: 200 });
     }) as unknown as typeof fetch;
 
+    const configModule = await import('../config');
+    const configSpy = spyOn(configModule, 'loadConfig').mockReturnValue({
+      ...configModule.DEFAULT_CONFIG,
+    });
+
     const { startServer } = await import('./http');
     await startServer(10000, spawnMock as never);
 
@@ -169,6 +174,7 @@ describe('startServer', () => {
     expect(fakeChild.unref).toHaveBeenCalled();
 
     existsSpy.mockRestore();
+    configSpy.mockRestore();
   });
 
   test('exits with error when server does not start within timeout', async () => {
@@ -181,6 +187,11 @@ describe('startServer', () => {
       throw new Error('not yet');
     }) as unknown as typeof fetch;
 
+    const configModule = await import('../config');
+    const configSpy = spyOn(configModule, 'loadConfig').mockReturnValue({
+      ...configModule.DEFAULT_CONFIG,
+    });
+
     const { startServer } = await import('./http');
     await startServer(100, spawnMock as never);
 
@@ -190,6 +201,7 @@ describe('startServer', () => {
     existsSpy.mockRestore();
     exitSpy.mockRestore();
     errorSpy.mockRestore();
+    configSpy.mockRestore();
   });
 });