From 903dec8cfcfaf247f3413969356c493d264bf3c3 Mon Sep 17 00:00:00 2001
From: abdolrhman-mo <abdelrhmanlearn@gmail.com>
Date: Tue, 24 Mar 2026 13:23:35 +0200
Subject: [PATCH] fix(browse): use detached child_process.spawn on Windows for
 server persistence
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Bun.spawn() with proc.unref() on Windows doesn't truly detach the server
subprocess — it dies when the CLI parent exits. This caused every $B command
to start a fresh Chromium instance at about:blank, making the browse binary
completely non-functional on Windows.

Fix: On Windows, use Node's child_process.spawn with { detached: true,
stdio: 'ignore' } which creates a truly independent process that survives
parent exit.

Tested on Windows 11 with Next.js 16 + Turbopack:
- Server persists between commands (no more "[browse] Starting server..." on every call)
- Pages render with full interactive elements
- goto + url returns the correct URL instead of about:blank

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 browse/src/cli.ts | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/browse/src/cli.ts b/browse/src/cli.ts
index 830b2e7ca..3e9af95dc 100644
--- a/browse/src/cli.ts
+++ b/browse/src/cli.ts
@@ -170,17 +170,31 @@ async function startServer(): Promise<ServerState> {
   // Start server as detached background process.
   // On Windows, Bun can't launch/connect to Playwright's Chromium (oven-sh/bun#4253, #9911).
   // Fall back to running the server under Node.js with Bun API polyfills.
+  // Additionally, Bun.spawn + unref() on Windows doesn't truly detach — the child dies
+  // when the CLI parent exits. Use Node's child_process.spawn with detached:true instead.
   const useNode = IS_WINDOWS && NODE_SERVER_SCRIPT;
   const serverCmd = useNode
     ? ['node', NODE_SERVER_SCRIPT]
     : ['bun', 'run', SERVER_SCRIPT];
-  const proc = Bun.spawn(serverCmd, {
-    stdio: ['ignore', 'pipe', 'pipe'],
-    env: { ...process.env, BROWSE_STATE_FILE: config.stateFile },
-  });
 
-  // Don't hold the CLI open
-  proc.unref();
+  if (IS_WINDOWS) {
+    // On Windows, Bun.spawn's unref() doesn't create a truly detached process.
+    // The server dies when the CLI exits. Use Node's child_process.spawn instead.
+    const { spawn: nodeSpawn } = require('child_process');
+    const child = nodeSpawn(serverCmd[0], serverCmd.slice(1), {
+      detached: true,
+      stdio: 'ignore',
+      env: { ...process.env, BROWSE_STATE_FILE: config.stateFile },
+    });
+    child.unref();
+  } else {
+    const proc = Bun.spawn(serverCmd, {
+      stdio: ['ignore', 'pipe', 'pipe'],
+      env: { ...process.env, BROWSE_STATE_FILE: config.stateFile },
+    });
+    // Don't hold the CLI open
+    proc.unref();
+  }
 
   // Wait for state file to appear
   const start = Date.now();