chore: check extension version on connect (#907)

extension/src/background.ts

@@ -19,6 +19,7 @@ import { RelayConnection, debugLog } from './relayConnection.js';
 type PageMessage = {
   type: 'connectToMCPRelay';
   mcpRelayUrl: string;
+  pwMcpVersion: string | null;
 } | {
   type: 'getTabs';
 } | {
@@ -49,7 +50,7 @@ class TabShareExtension {
   private _onMessage(message: PageMessage, sender: chrome.runtime.MessageSender, sendResponse: (response: any) => void) {
     switch (message.type) {
       case 'connectToMCPRelay':
-        this._connectToRelay(sender.tab!.id!, message.mcpRelayUrl!).then(
+        this._connectToRelay(sender.tab!.id!, message.mcpRelayUrl, message.pwMcpVersion).then(
             () => sendResponse({ success: true }),
             (error: any) => sendResponse({ success: false, error: error.message }));
         return true;
@@ -77,7 +78,11 @@ class TabShareExtension {
     return false;
   }
 
-  private async _connectToRelay(selectorTabId: number, mcpRelayUrl: string): Promise<void> {
+  private async _connectToRelay(selectorTabId: number, mcpRelayUrl: string, pwMcpVersion: string | null): Promise<void> {
+    const version = chrome.runtime.getManifest().version;
+    if (pwMcpVersion !== version)
+      throw new Error(`Incompatible Playwright MCP version: ${pwMcpVersion} (extension version: ${version}). Please install the latest version of the extension.`);
+
     try {
       debugLog(`Connecting to relay at ${mcpRelayUrl}`);
       const socket = new WebSocket(mcpRelayUrl);
@@ -96,8 +101,9 @@ class TabShareExtension {
       this._pendingTabSelection.set(selectorTabId, { connection });
       debugLog(`Connected to MCP relay`);
     } catch (error: any) {
-      debugLog(`Failed to connect to MCP relay:`, error.message);
+      const message = `Failed to connect to MCP relay: ${error.message}`;
-      throw error;
+      debugLog(message);
+      throw new Error(message);
     }
   }
 

extension/src/ui/connect.tsx

@@ -54,16 +54,22 @@ const ConnectApp: React.FC = () => {
       return;
     }
 
-    void connectToMCPRelay(relayUrl);
+    void connectToMCPRelay(relayUrl, params.get('pwMcpVersion'));
     void loadTabs();
   }, []);
 
-  const connectToMCPRelay = useCallback(async (mcpRelayUrl: string) => {
+  const handleReject = useCallback((message: string) => {
-    const response = await chrome.runtime.sendMessage({ type: 'connectToMCPRelay', mcpRelayUrl });
+    setShowButtons(false);
-    if (!response.success)
+    setShowTabList(false);
-      setStatus({ type: 'error', message: 'Failed to connect to MCP relay: ' + response.error });
+    setStatus({ type: 'error', message });
   }, []);
 
+  const connectToMCPRelay = useCallback(async (mcpRelayUrl: string, pwMcpVersion: string | null) => {
+    const response = await chrome.runtime.sendMessage({ type: 'connectToMCPRelay', mcpRelayUrl, pwMcpVersion  });
+    if (!response.success)
+      handleReject(response.error);
+  }, [handleReject]);
+
   const loadTabs = useCallback(async () => {
     const response = await chrome.runtime.sendMessage({ type: 'getTabs' });
     if (response.success)
@@ -100,22 +106,16 @@ const ConnectApp: React.FC = () => {
     }
   }, [clientInfo, mcpRelayUrl]);
 
-  const handleReject = useCallback(() => {
-    setShowButtons(false);
-    setShowTabList(false);
-    setStatus({ type: 'error', message: 'Connection rejected. This tab can be closed.' });
-  }, []);
-
   useEffect(() => {
     const listener = (message: any) => {
       if (message.type === 'connectionTimeout')
-        handleReject();
+        handleReject('Connection timed out.');
     };
     chrome.runtime.onMessage.addListener(listener);
     return () => {
       chrome.runtime.onMessage.removeListener(listener);
     };
-  }, []);
+  }, [handleReject]);
 
   return (
     <div className='app-container'>
@@ -124,7 +124,7 @@ const ConnectApp: React.FC = () => {
           <div className='status-container'>
             <StatusBanner type={status.type} message={status.message} />
             {showButtons && (
-              <Button variant='reject' onClick={handleReject}>
+              <Button variant='reject' onClick={() => handleReject('Connection rejected. This tab can be closed.')}>
                 Reject
               </Button>
             )}

extension/tests/extension.spec.ts

@@ -14,12 +14,15 @@
  * limitations under the License.
  */
 
+import fs from 'fs';
+import path from 'path';
 import { fileURLToPath } from 'url';
 import { chromium } from 'playwright';
+import packageJSON from '../../package.json' assert { type: 'json' };
 import { test as base, expect } from '../../tests/fixtures.js';
 
-import type { BrowserContext } from 'playwright';
 import type { Client } from '@modelcontextprotocol/sdk/client/index.js';
+import type { BrowserContext } from 'playwright';
 import type { StartClient } from '../../tests/fixtures.js';
 
 type BrowserWithExtension = {
@@ -27,14 +30,22 @@ type BrowserWithExtension = {
   launch: (mode?: 'disable-extension') => Promise<BrowserContext>;
 };
 
-const test = base.extend<{ browserWithExtension: BrowserWithExtension }>({
+type TestFixtures = {
-  browserWithExtension: async ({ mcpBrowser }, use, testInfo) => {
+  browserWithExtension: BrowserWithExtension,
+  pathToExtension: string,
+  useShortConnectionTimeout: (timeoutMs: number) => void
+};
+
+const test = base.extend<TestFixtures>({
+  pathToExtension: async ({}, use) => {
+    await use(fileURLToPath(new URL('../dist', import.meta.url)));
+  },
+
+  browserWithExtension: async ({ mcpBrowser, pathToExtension }, use, testInfo) => {
     // The flags no longer work in Chrome since
     // https://chromium.googlesource.com/chromium/src/+/290ed8046692651ce76088914750cb659b65fb17%5E%21/chrome/browser/extensions/extension_service.cc?pli=1#
     test.skip('chromium' !== mcpBrowser, '--load-extension is not supported for official builds of Chromium');
 
-    const pathToExtension = fileURLToPath(new URL('../dist', import.meta.url));
-
     let browserContext: BrowserContext | undefined;
     const userDataDir = testInfo.outputPath('extension-user-data-dir');
     await use({
@@ -60,9 +71,16 @@ const test = base.extend<{ browserWithExtension: BrowserWithExtension }>({
         return browserContext;
       }
     });
-
     await browserContext?.close();
   },
+
+  useShortConnectionTimeout: async ({}, use) => {
+    await use((timeoutMs: number) => {
+      process.env.PWMCP_TEST_CONNECTION_TIMEOUT = timeoutMs.toString();
+    });
+    process.env.PWMCP_TEST_CONNECTION_TIMEOUT = undefined;
+  },
+
 });
 
 async function startAndCallConnectTool(browserWithExtension: BrowserWithExtension, startClient: StartClient): Promise<Client> {
@@ -99,6 +117,21 @@ async function startWithExtensionFlag(browserWithExtension: BrowserWithExtension
   return client;
 }
 
+const testWithOldVersion = test.extend({
+  pathToExtension: async ({}, use, testInfo) => {
+    const extensionDir = testInfo.outputPath('extension');
+    const oldPath = fileURLToPath(new URL('../dist', import.meta.url));
+
+    await fs.promises.cp(oldPath, extensionDir, { recursive: true });
+    const manifestPath = path.join(extensionDir, 'manifest.json');
+    const manifest = JSON.parse(await fs.promises.readFile(manifestPath, 'utf8'));
+    manifest.version = '0.0.1';
+    await fs.promises.writeFile(manifestPath, JSON.stringify(manifest, null, 2) + '\n');
+
+    await use(extensionDir);
+  },
+});
+
 for (const [mode, startClientMethod] of [
   ['connect-tool', startAndCallConnectTool],
   ['extension-flag', startWithExtensionFlag],
@@ -160,8 +193,8 @@ for (const [mode, startClientMethod] of [
     expect(browserContext.pages()).toHaveLength(4);
   });
 
-  test(`extension not installed timeout (${mode})`, async ({ browserWithExtension, startClient, server }) => {
+  test(`extension not installed timeout (${mode})`, async ({ browserWithExtension, startClient, server, useShortConnectionTimeout }) => {
-    process.env.PWMCP_TEST_CONNECTION_TIMEOUT = '100';
+    useShortConnectionTimeout(100);
 
     const browserContext = await browserWithExtension.launch();
 
@@ -180,8 +213,32 @@ for (const [mode, startClientMethod] of [
     });
 
     await confirmationPagePromise;
+  });
 
-    process.env.PWMCP_TEST_CONNECTION_TIMEOUT = undefined;
+  testWithOldVersion(`extension version mismatch (${mode})`, async ({ browserWithExtension, startClient, server, useShortConnectionTimeout }) => {
+    useShortConnectionTimeout(500);
+
+    // Prelaunch the browser, so that it is properly closed after the test.
+    const browserContext = await browserWithExtension.launch();
+
+    const client = await startClientMethod(browserWithExtension, startClient);
+
+    const confirmationPagePromise = browserContext.waitForEvent('page', page => {
+      return page.url().startsWith('chrome-extension://jakfalbnbhgkpmoaakfflhflbfpkailf/connect.html');
+    });
+
+    const navigateResponse = client.callTool({
+      name: 'browser_navigate',
+      arguments: { url: server.HELLO_WORLD },
+    });
+
+    const confirmationPage = await confirmationPagePromise;
+    await expect(confirmationPage.locator('.status-banner')).toHaveText(`Incompatible Playwright MCP version: ${packageJSON.version} (extension version: 0.0.1). Please install the latest version of the extension.`);
+
+    expect(await navigateResponse).toHaveResponse({
+      result: expect.stringContaining('Extension connection timeout.'),
+      isError: true,
+    });
   });
 
 }

src/extension/cdpRelay.ts

@@ -29,6 +29,8 @@ import { WebSocket, WebSocketServer } from 'ws';
 import { httpAddressToString } from '../mcp/http.js';
 import { logUnhandledError } from '../utils/log.js';
 import { ManualPromise } from '../utils/manualPromise.js';
+import { packageJSON } from '../utils/package.js';
+
 import type websocket from 'ws';
 import type { ClientInfo } from '../browserContextFactory.js';
 
@@ -113,7 +115,12 @@ export class CDPRelayServer {
     // Need to specify "key" in the manifest.json to make the id stable when loading from file.
     const url = new URL('chrome-extension://jakfalbnbhgkpmoaakfflhflbfpkailf/connect.html');
     url.searchParams.set('mcpRelayUrl', mcpRelayEndpoint);
-    url.searchParams.set('client', JSON.stringify(clientInfo));
+    const client = {
+      name: clientInfo.name,
+      version: clientInfo.version,
+    };
+    url.searchParams.set('client', JSON.stringify(client));
+    url.searchParams.set('pwMcpVersion', packageJSON.version);
     const href = url.toString();
     const executableInfo = registry.findExecutable(this._browserChannel);
     if (!executableInfo)