fix(browser): close orphaned browser before relaunch to stop headless_shell leak

src/browser/manager.ts

@@ -15,72 +15,101 @@ let _config: BrowserConfig;
 const MAX_CONSOLE = 500;
 const MAX_NETWORK = 500;
 
-export async function launchBrowser(config: BrowserConfig): Promise<void> {
-  _config = config;
-
+/**
+ * Close whatever browser is currently referenced, swallowing any error.
+ * Used to guarantee we never abandon a live browser process before
+ * (re)launching — otherwise the old `headless_shell` leaks. Best-effort:
+ * a close failure must not block the relaunch.
+ */
+async function discardBrowser(b: Browser | null): Promise<void> {
+  if (!b) return;
   try {
-    const launchOptions: Parameters<typeof chromium.launch>[0] = {
-      headless: config.headless,
-      args: [
-        '--no-first-run',
-        '--no-default-browser-check',
-        `--window-size=${config.viewport.width},${config.viewport.height + 100}`,
-      ],
-    };
-
-    if (config.channel) {
-      launchOptions.channel = config.channel as any;
-    }
+    await b.close();
+  } catch (err) {
+    console.error('[glance] Error closing previous browser (ignored):', err);
+  }
+}
 
-    _browser = await chromium.launch(launchOptions);
+export async function launchBrowser(config: BrowserConfig): Promise<void> {
+  _config = config;
 
-    _browser.on('disconnected', () => {
+  // Never abandon an existing browser process: close it before launching a
+  // new one. ensureBrowser() relaunches when `_browser` is null/disconnected,
+  // and the `disconnected` handler nulls `_browser` while the OS process may
+  // still be alive — so without this guard each relaunch orphaned a live
+  // headless_shell, accumulating until OOM.
+  await discardBrowser(_browser);
+  _browser = null;
+  _context = null;
+  _pages.clear();
+  _activePageId = null;
+
+  const attach = async (browser: Browser, label: string): Promise<void> => {
+    _browser = browser;
+    browser.on('disconnected', () => {
       console.error('[glance] Browser disconnected, will relaunch on next tool call');
-      _browser = null;
-      _context = null;
-      _pages.clear();
-      _activePageId = null;
+      // Fully release the (now-dead) browser; close() is a no-op once the
+      // process is gone but cleans up Playwright-side handles deterministically.
+      void discardBrowser(browser);
+      if (_browser === browser) {
+        _browser = null;
+        _context = null;
+        _pages.clear();
+        _activePageId = null;
+      }
     });
 
-    _context = await _browser.newContext({
+    _context = await browser.newContext({
       viewport: config.viewport,
       ignoreHTTPSErrors: config.securityProfile === 'local-dev',
     });
 
-    // Create initial page
     const page = await _context.newPage();
     const pageId = randomUUID();
     _pages.set(pageId, page);
     _activePageId = pageId;
     _setupPageListeners(page, pageId);
 
     _readyResolve?.();
-    console.error('[glance] Browser launched and ready');
+    console.error(`[glance] Browser launched${label} and ready`);
+  };
+
+  try {
+    const launchOptions: Parameters<typeof chromium.launch>[0] = {
+      headless: config.headless,
+      args: [
+        '--no-first-run',
+        '--no-default-browser-check',
+        `--window-size=${config.viewport.width},${config.viewport.height + 100}`,
+      ],
+    };
+
+    if (config.channel) {
+      launchOptions.channel = config.channel as any;
+    }
+
+    await attach(await chromium.launch(launchOptions), '');
   } catch (err) {
     console.error('[glance] Failed to launch browser:', err);
-    // Try with bundled chromium path detection disabled, fallback to system chrome
+    // A browser may have launched on the first attempt before a later step
+    // (newContext/newPage) threw — discard it so the fallback launch can't
+    // orphan it.
+    await discardBrowser(_browser);
+    _browser = null;
+    // Try the system Chrome channel as a fallback.
     try {
-      _browser = await chromium.launch({
-        headless: config.headless,
-        channel: 'chrome',
-        args: ['--no-first-run', '--no-default-browser-check'],
-      });
-
-      _context = await _browser.newContext({
-        viewport: config.viewport,
-        ignoreHTTPSErrors: config.securityProfile === 'local-dev',
-      });
-
-      const page = await _context.newPage();
-      const pageId = randomUUID();
-      _pages.set(pageId, page);
-      _activePageId = pageId;
-      _setupPageListeners(page, pageId);
-
-      _readyResolve?.();
-      console.error('[glance] Browser launched (system Chrome) and ready');
+      await attach(
+        await chromium.launch({
+          headless: config.headless,
+          channel: 'chrome',
+          args: ['--no-first-run', '--no-default-browser-check'],
+        }),
+        ' (system Chrome)',
+      );
     } catch (err2) {
       console.error('[glance] Failed to launch system Chrome:', err2);
+      await discardBrowser(_browser);
+      _browser = null;
       _readyResolve?.();
     }
   }