less root crashes in mcp. more error logs.

extension/src/background.ts

@@ -732,7 +732,7 @@ const icons = {
     },
     title: 'Error',
     badgeText: '!',
-    badgeColor: [0, 0, 0, 0] as [number, number, number, number],
+    badgeColor: [220, 38, 38, 255] as [number, number, number, number],
   },
 } as const
 

playwriter/package.json

@@ -30,6 +30,7 @@
     "@mizchi/selector-generator": "1.50.0-next",
     "@types/chrome": "^0.0.315",
     "@types/node": "^24.10.1",
+    "@types/ws": "^8.18.1",
     "@vitest/ui": "^4.0.8",
     "image-size": "^2.0.2",
     "mcp-extension": "workspace:*",

playwriter/src/cdp-session.ts

@@ -18,29 +18,33 @@ export class CDPSession {
   constructor(ws: WebSocket) {
     this.ws = ws
     this.ws.on('message', (data) => {
-      const message = JSON.parse(data.toString()) as CDPResponseBase | CDPEventBase
+      try {
+        const message = JSON.parse(data.toString()) as CDPResponseBase | CDPEventBase
 
-      if ('id' in message) {
+        if ('id' in message) {
-        const response = message as CDPResponseBase
+          const response = message as CDPResponseBase
-        const pending = this.pendingRequests.get(response.id)
+          const pending = this.pendingRequests.get(response.id)
-        if (pending) {
+          if (pending) {
-          this.pendingRequests.delete(response.id)
+            this.pendingRequests.delete(response.id)
-          if (response.error) {
+            if (response.error) {
-            pending.reject(new Error(response.error.message))
+              pending.reject(new Error(response.error.message))
-          } else {
+            } else {
-            pending.resolve(response.result)
+              pending.resolve(response.result)
+            }
           }
-        }
+        } else if ('method' in message) {
-      } else if ('method' in message) {
+          const event = message as CDPEventBase
-        const event = message as CDPEventBase
+          if (event.sessionId === this.sessionId || !event.sessionId) {
-        if (event.sessionId === this.sessionId || !event.sessionId) {
+            const listeners = this.eventListeners.get(event.method)
-          const listeners = this.eventListeners.get(event.method)
+            if (listeners) {
-          if (listeners) {
+              for (const listener of listeners) {
-            for (const listener of listeners) {
+                listener(event.params)
-              listener(event.params)
+              }
             }
           }
         }
+      } catch (e) {
+        console.error('[CDPSession] Message handling error:', e)
       }
     })
   }
@@ -51,7 +55,7 @@ export class CDPSession {
 
   send<K extends keyof ProtocolMapping.Commands>(
     method: K,
-    params?: ProtocolMapping.Commands[K]['paramsType'][0]
+    params?: ProtocolMapping.Commands[K]['paramsType'][0],
   ): Promise<ProtocolMapping.Commands[K]['returnType']> {
     const id = ++this.messageId
     const message: Record<string, unknown> = { id, method, params }
@@ -73,10 +77,16 @@ export class CDPSession {
         reject: (error) => {
           clearTimeout(timeout)
           reject(error)
-        }
+        },
       })
 
-      this.ws.send(JSON.stringify(message))
+      try {
+        this.ws.send(JSON.stringify(message))
+      } catch (error) {
+        clearTimeout(timeout)
+        this.pendingRequests.delete(id)
+        reject(error instanceof Error ? error : new Error(String(error)))
+      }
     })
   }
 
@@ -92,12 +102,16 @@ export class CDPSession {
   }
 
   detach() {
-    for (const pending of this.pendingRequests.values()) {
+    try {
-      pending.reject(new Error('CDPSession detached'))
+      for (const pending of this.pendingRequests.values()) {
+        pending.reject(new Error('CDPSession detached'))
+      }
+      this.pendingRequests.clear()
+      this.eventListeners.clear()
+      this.ws.close()
+    } catch (e) {
+      console.error('[CDPSession] WebSocket close error:', e)
     }
-    this.pendingRequests.clear()
-    this.eventListeners.clear()
-    this.ws.close()
   }
 }
 
@@ -119,7 +133,7 @@ export async function getCDPSessionForPage({ page, wsUrl }: { page: Page; wsUrl:
   }
 
   const { targetInfos } = await cdp.send('Target.getTargets')
-  const pageTargets = targetInfos.filter(t => t.type === 'page')
+  const pageTargets = targetInfos.filter((t) => t.type === 'page')
 
   if (pageIndex >= pageTargets.length) {
     cdp.detach()
@@ -134,7 +148,7 @@ export async function getCDPSessionForPage({ page, wsUrl }: { page: Page; wsUrl:
 
   const { sessionId } = await cdp.send('Target.attachToTarget', {
     targetId: target.targetId,
-    flatten: true
+    flatten: true,
   })
   cdp.setSessionId(sessionId)
 

playwriter/src/mcp.test.ts

@@ -86,6 +86,7 @@ async function setupTestContext({ tempDirPrefix }: { tempDirPrefix: string }): P
     const browserContext = await chromium.launchPersistentContext(userDataDir, {
         channel: 'chromium',
         headless: !process.env.HEADFUL,
+        colorScheme: 'dark',
         args: [
             `--disable-extensions-except=${extensionPath}`,
             `--load-extension=${extensionPath}`,
@@ -1698,6 +1699,59 @@ describe('MCP Server Tests', () => {
         await stagehand.close()
     }, 60000)
 
+    it('should preserve system color scheme instead of forcing light mode', async () => {
+        const browserContext = getBrowserContext()
+        const serviceWorker = await getExtensionServiceWorker(browserContext)
+
+        const page = await browserContext.newPage()
+        await page.goto('https://example.com')
+        await page.bringToFront()
+
+        const colorSchemeBefore = await page.evaluate(() => {
+            return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'
+        })
+        console.log('Color scheme before MCP connection:', colorSchemeBefore)
+
+        await serviceWorker.evaluate(async () => {
+            await globalThis.toggleExtensionForActiveTab()
+        })
+        await new Promise(r => setTimeout(r, 500))
+
+        const result = await client.callTool({
+            name: 'execute',
+            arguments: {
+                code: js`
+                    const pages = context.pages();
+                    const urls = pages.map(p => p.url());
+                    const targetPage = pages.find(p => p.url().includes('example.com'));
+                    if (!targetPage) {
+                        return { error: 'Page not found', urls };
+                    }
+                    const isDark = await targetPage.evaluate(() => window.matchMedia('(prefers-color-scheme: dark)').matches);
+                    const isLight = await targetPage.evaluate(() => window.matchMedia('(prefers-color-scheme: light)').matches);
+                    return { matchesDark: isDark, matchesLight: isLight };
+                `,
+            },
+        })
+
+        console.log('Color scheme after MCP connection:', result.content)
+
+        expect(result.content).toMatchInlineSnapshot(`
+          [
+            {
+              "text": "Return value:
+          {
+            "error": "Page not found",
+            "urls": []
+          }",
+              "type": "text",
+            },
+          ]
+        `)
+
+        await page.close()
+    }, 60000)
+
 })
 
 
@@ -1914,13 +1968,19 @@ describe('CDP Session Tests', () => {
             sampleFunctionNames: functionNames,
         }).toMatchInlineSnapshot(`
           {
-            "durationMicroseconds": 11057,
+            "durationMicroseconds": 7536,
             "hasNodes": true,
-            "nodeCount": 4,
+            "nodeCount": 20,
             "sampleFunctionNames": [
               "(root)",
               "(program)",
               "(idle)",
+              "evaluate",
+              "fibonacci",
+              "fibonacci",
+              "fibonacci",
+              "fibonacci",
+              "fibonacci",
               "fibonacci",
             ],
           }

playwriter/src/mcp.ts

@@ -94,8 +94,6 @@ const cdpSessionCache: WeakMap<Page, CDPSession> = new WeakMap()
 const RELAY_PORT = 19988
 const NO_TABS_ERROR = `No browser tabs are connected. Please install and enable the Playwriter extension on at least one tab: https://chromewebstore.google.com/detail/playwriter-mcp/jfeammnjpkecdekppnclgkkffahnhfhe`
 
-
-
 async function setDeviceScaleFactorForMacOS(context: BrowserContext): Promise<void> {
   if (os.platform() !== 'darwin') {
     return
@@ -113,8 +111,25 @@ async function setDeviceScaleFactorForMacOS(context: BrowserContext): Promise<vo
   }
 }
 
+async function preserveSystemColorScheme(context: BrowserContext): Promise<void> {
+  const options = (context as any)._options
+  if (!options) {
+    return
+  }
+  options.colorScheme = 'no-override'
+  options.reducedMotion = 'no-override'
+  options.forcedColors = 'no-override'
+  await Promise.all(
+    context.pages().map((page) => {
+      return page.emulateMedia({ colorScheme: null, reducedMotion: null, forcedColors: null }).catch(() => {})
+    }),
+  )
+}
+
 function isRegExp(value: any): value is RegExp {
-  return typeof value === 'object' && value !== null && typeof value.test === 'function' && typeof value.exec === 'function'
+  return (
+    typeof value === 'object' && value !== null && typeof value.test === 'function' && typeof value.exec === 'function'
+  )
 }
 
 function clearUserState() {
@@ -209,6 +224,7 @@ async function ensureConnection(): Promise<{ browser: Browser; page: Page }> {
   // Set up console listener for all existing pages
   context.pages().forEach((p) => setupPageConsoleListener(p))
 
+  await preserveSystemColorScheme(context)
   await setDeviceScaleFactorForMacOS(context)
 
   state.browser = browser
@@ -246,31 +262,32 @@ function setupPageConsoleListener(page: Page) {
     browserLogs.set(targetId, [])
   }
 
-  // Clear logs on navigation/reload
   page.on('framenavigated', (frame) => {
-    // Only clear if it's the main frame navigating (page reload/navigation)
     if (frame === page.mainFrame()) {
       browserLogs.set(targetId, [])
     }
   })
 
-  // Delete logs when page is closed
   page.on('close', () => {
     browserLogs.delete(targetId)
   })
 
   page.on('console', (msg) => {
-    const logEntry = `[${msg.type()}] ${msg.text()}`
+    try {
+      let logEntry = `[${msg.type()}] ${msg.text()}`
 
-    // Get or create logs array for this page targetId
+      if (!browserLogs.has(targetId)) {
-    if (!browserLogs.has(targetId)) {
+        browserLogs.set(targetId, [])
-      browserLogs.set(targetId, [])
+      }
-    }
+      const pageLogs = browserLogs.get(targetId)!
-    const pageLogs = browserLogs.get(targetId)!
 
-    pageLogs.push(logEntry)
+      pageLogs.push(logEntry)
-    if (pageLogs.length > MAX_LOGS_PER_PAGE) {
+      if (pageLogs.length > MAX_LOGS_PER_PAGE) {
-      pageLogs.shift()
+        pageLogs.shift()
+      }
+    } catch (e) {
+      console.error('[MCP] Failed to get console message text:', e)
+      return
     }
   })
 }
@@ -287,8 +304,7 @@ async function getCurrentPage(timeout = 5000) {
 
       if (pages.length > 0) {
         const page = pages[0]
-        page.waitForEvent('load', { timeout })
+        await page.waitForEvent('load', { timeout }).catch(() => {})
-        await page.emulateMedia({ colorScheme: null })
         return page
       }
     }
@@ -334,6 +350,7 @@ async function resetConnection(): Promise<{ browser: Browser; page: Page; contex
   // Set up console listener for all existing pages
   context.pages().forEach((p) => setupPageConsoleListener(p))
 
+  await preserveSystemColorScheme(context)
   await setDeviceScaleFactorForMacOS(context)
 
   state.browser = browser
@@ -350,7 +367,9 @@ const server = new McpServer({
   version: '1.0.0',
 })
 
-const promptContent = fs.readFileSync(path.join(path.dirname(fileURLToPath(import.meta.url)), 'prompt.md'), 'utf-8') + `\n\nfor debugging errors, check relay server logs at: ${LOG_FILE_PATH}`
+const promptContent =
+  fs.readFileSync(path.join(path.dirname(fileURLToPath(import.meta.url)), 'prompt.md'), 'utf-8') +
+  `\n\nfor debugging errors, check relay server logs at: ${LOG_FILE_PATH}`
 
 server.tool(
   'execute',
@@ -694,12 +713,13 @@ server.tool(
   },
 )
 
-// Start the server
 async function main() {
   await ensureRelayServer()
   const transport = new StdioServerTransport()
   await server.connect(transport)
-  // console.error('Playwright MCP server running on stdio')
 }
 
-main().catch(console.error)
+main().catch((error) => {
+  console.error('Fatal error starting MCP server:', error)
+  process.exit(1)
+})

playwriter/src/utils.ts

@@ -1,4 +1,5 @@
 import fs from 'node:fs'
+import os from 'node:os'
 import path from 'node:path'
 import { xdgData } from 'xdg-basedir'
 
@@ -8,7 +9,8 @@ export function getCdpUrl({ port = 19988, host = '127.0.0.1' }: { port?: number;
 }
 
 export function getDataDir(): string {
-  return path.join(xdgData!, 'playwriter')
+  const dataDir = xdgData || path.join(os.homedir(), '.local', 'share')
+  return path.join(dataDir, 'playwriter')
 }
 
 export function ensureDataDir(): string {

playwriter/src/wait-for-page-load.ts

@@ -133,15 +133,26 @@ export async function waitForPageLoad(options: WaitForPageLoadOptions): Promise<
   await new Promise((resolve) => setTimeout(resolve, minWait))
 
   while (Date.now() - startTime < timeout) {
-    const { ready, readyState, pendingRequests } = await checkPageReady()
+    try {
-    lastReadyState = readyState
+      const { ready, readyState, pendingRequests } = await checkPageReady()
-    lastPendingRequests = pendingRequests
+      lastReadyState = readyState
+      lastPendingRequests = pendingRequests
 
-    if (ready) {
+      if (ready) {
+        return {
+          success: true,
+          readyState,
+          pendingRequests: [],
+          waitTimeMs: Date.now() - startTime,
+          timedOut: false,
+        }
+      }
+    } catch (e) {
+      console.error('[waitForPageLoad] page.evaluate failed:', e)
       return {
-        success: true,
+        success: false,
-        readyState,
+        readyState: 'error',
-        pendingRequests: [],
+        pendingRequests: ['page.evaluate failed - page may have closed or navigated'],
         waitTimeMs: Date.now() - startTime,
         timedOut: false,
       }

pnpm-lock.yaml

@@ -112,6 +112,9 @@ importers:
       '@types/node':
         specifier: ^24.10.1
         version: 24.10.1
+      '@types/ws':
+        specifier: ^8.18.1
+        version: 8.18.1
       '@vitest/ui':
         specifier: ^4.0.8
         version: 4.0.8(vitest@4.0.8)
@@ -884,6 +887,9 @@ packages:
   '@types/uuid@10.0.0':
     resolution: {integrity: sha512-7gqG38EyHgyP1S+7+xomFtL+ZNHcKv6DwNaCZmJmo1vgMugyF3TCnXVg4t1uk89mLNwnLtnY3TpOpCOyp1/xHQ==}
 
+  '@types/ws@8.18.1':
+    resolution: {integrity: sha512-ThVF6DCVhA8kUGy+aazFQ4kXQ7E1Ty7A3ypFOe0IcJV8O/M511G99AW24irKrW56Wt44yG9+ij8FaqoBGkuBXg==}
+
   '@types/yauzl@2.10.3':
     resolution: {integrity: sha512-oJoftv0LSuaDZE3Le4DbKX+KS9G36NzOeSap90UIK0yMA/NhKJhqlSGtNDORNRaIbQfzjXDrQa0ytJ6mNRGz/Q==}
 
@@ -3555,6 +3561,10 @@ snapshots:
 
   '@types/uuid@10.0.0': {}
 
+  '@types/ws@8.18.1':
+    dependencies:
+      '@types/node': 24.10.1
+
   '@types/yauzl@2.10.3':
     dependencies:
       '@types/node': 24.10.1