Fix electron bug

Author: Sg312

apps/desktop/src/main/browser-agent/session.test.ts

@@ -15,6 +15,7 @@ interface MockView {
     }
     setWindowOpenHandler: ReturnType<typeof vi.fn>
     loadURL: ReturnType<typeof vi.fn>
+    isDestroyed: ReturnType<typeof vi.fn>
     setBackgroundThrottling: ReturnType<typeof vi.fn>
     capturePage: ReturnType<typeof vi.fn>
   }
@@ -166,6 +167,67 @@ describe('browser-agent session', () => {
     expect(removeChildView).toHaveBeenCalledWith(tab.view)
   })
 
+  it('clears a stale attachment without touching a destroyed host window', () => {
+    const tab = session.ensureTab()
+    session.setPanelBounds({ x: 100, y: 50, width: 800, height: 600 })
+    const staleContent = (
+      win as unknown as {
+        contentView: {
+          removeChildView: ReturnType<typeof vi.fn>
+        }
+      }
+    ).contentView
+    staleContent.removeChildView.mockClear()
+    staleContent.removeChildView.mockImplementation(() => {
+      throw new Error('Object has been destroyed')
+    })
+    vi.mocked(win.isDestroyed).mockReturnValue(true)
+
+    const replacement = mainWindowMock()
+    session.initSession(
+      {
+        onSessionClosed: vi.fn(),
+        onTabCreated: vi.fn(),
+        onActiveTabChanged: vi.fn(),
+        onTabsChanged: vi.fn(),
+        onTabThemeChanged: vi.fn(),
+        onDownloadBlocked: vi.fn(),
+      },
+      () => replacement
+    )
+
+    expect(() => session.setPanelBounds(null)).not.toThrow()
+    expect(staleContent.removeChildView).not.toHaveBeenCalled()
+
+    session.setPanelBounds({ x: 100, y: 50, width: 800, height: 600 })
+    const replacementContent = (
+      replacement as unknown as {
+        contentView: {
+          addChildView: ReturnType<typeof vi.fn>
+        }
+      }
+    ).contentView
+    expect(replacementContent.addChildView).toHaveBeenCalledWith(tab.view)
+  })
+
+  it('clears a stale attachment without touching a destroyed child view', () => {
+    const tab = session.ensureTab()
+    const view = tab.view as unknown as MockView
+    session.setPanelBounds({ x: 100, y: 50, width: 800, height: 600 })
+    const content = (
+      win as unknown as {
+        contentView: {
+          removeChildView: ReturnType<typeof vi.fn>
+        }
+      }
+    ).contentView
+    content.removeChildView.mockClear()
+    view.webContents.isDestroyed.mockReturnValue(true)
+
+    expect(() => session.setPanelBounds(null)).not.toThrow()
+    expect(content.removeChildView).not.toHaveBeenCalled()
+  })
+
   it('scales panel bounds by the main window zoom factor', () => {
     const winZoomed = mainWindowMock()
     ;(

apps/desktop/src/main/browser-agent/session.ts

@@ -7,6 +7,7 @@ import {
   MAX_BROWSER_TABS,
 } from '@sim/browser-protocol'
 import { createLogger } from '@sim/logger'
+import { getErrorMessage } from '@sim/utils/errors'
 import type { BrowserWindow, Session, WebContents } from 'electron'
 import { nativeTheme, WebContentsView } from 'electron'
 import { registerAgentWebContents } from '@/main/browser-agent/registry'
@@ -206,6 +207,29 @@ let attachedView: WebContentsView | null = null
 let lastAppliedBounds = ''
 let lastAppliedVisibility: boolean | null = null
 
+/**
+ * Clears the tracked attachment before touching Electron objects so a stale
+ * host or child view cannot leave layout permanently wedged after teardown.
+ */
+function detachAttachedView(): void {
+  const view = attachedView
+  const win = hostedWindow
+  attachedView = null
+  hostedWindow = null
+  lastAppliedBounds = ''
+  lastAppliedVisibility = null
+
+  if (!view || !win) return
+  try {
+    if (win.isDestroyed() || view.webContents.isDestroyed()) return
+    win.contentView.removeChildView(view)
+  } catch (error) {
+    logger.warn('Could not detach embedded browser view', {
+      error: getErrorMessage(error, 'unknown'),
+    })
+  }
+}
+
 /**
  * Captures the current browser frame for the renderer to display while the
  * native view is hidden beneath an overlay. Captures stay hidden so Chromium
@@ -246,10 +270,7 @@ function layout(): void {
 
   if (!showing || hostedWindow !== win || attachedView !== active?.view) {
     if (attachedView) {
-      hostedWindow?.contentView.removeChildView(attachedView)
-      attachedView = null
-      lastAppliedBounds = ''
-      lastAppliedVisibility = null
+      detachAttachedView()
     }
   }
   if (!showing || !active || !win || panelBounds === null) {
@@ -369,10 +390,7 @@ export function closeTab(tabId: string): void {
   if (index < 0) throw new SessionError(`No tab with id ${tabId} — call browser_list_tabs.`)
   const [tab] = tabs.splice(index, 1)
   if (attachedView === tab.view) {
-    hostedWindow?.contentView.removeChildView(tab.view)
-    attachedView = null
-    lastAppliedBounds = ''
-    lastAppliedVisibility = null
+    detachAttachedView()
   }
   tab.view.webContents.close()
   if (activeTabId === tab.id) {