chore: prep devtools app by pavelfeldman · Pull Request #39231 · microsoft/playwright

pavelfeldman · 2026-02-11T19:28:10Z

No description provided.

yury-s · 2026-02-11T19:42:50Z

packages/playwright/src/mcp/terminal/commands.ts


-const show = declareCommand({
+const devtoolsShow = declareCommand({
  name: 'show',


Drop this command?

Copilot

Pull request overview

Prepares groundwork for a standalone DevTools “app” flow by introducing a new internal protocol method for setting the dock tile icon, refactoring DevTools start/stop tooling, and removing the old tray daemon implementation/dependency.

Changes:

Add internal Page.setDockTile protocol method and wire it through client/server/dispatcher layers (Chromium implementation; other engines stubbed).
Introduce a new devtoolsApp launcher (replacing the removed tray daemon) and update CLI command routing.
Refactor DevTools MCP tools and update DevTools frontend connection logic to expect a ?ws= URL parameter.

Reviewed changes

Copilot reviewed 22 out of 25 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
packages/protocol/src/protocol.yml	Adds internal `Page.setDockTile` protocol command definition.
packages/protocol/src/channels.d.ts	Adds typed channel method + params for `setDockTile`.
packages/playwright/src/mcp/terminal/trayDaemon.ts	Removes tray daemon implementation.
packages/playwright/src/mcp/terminal/program.ts	Re-routes `show` command to launch `devtoolsApp.js`.
packages/playwright/src/mcp/terminal/devtoolsApp.ts	Adds new DevTools “app” launcher and singleton socket handling.
packages/playwright/src/mcp/terminal/commands.ts	Splits DevTools commands into `show`, `devtools-start`, `devtools-stop`.
packages/playwright/src/mcp/terminal/appIcon.png	Adds app icon used by `devtoolsApp`.
packages/playwright/src/mcp/browser/tools/devtools.ts	Renames tool(s) and adds devtools start/stop MCP tools.
packages/playwright/src/mcp/browser/tools.ts	Switches tool registration from removed `show` tool to new `devtools` tools.
packages/playwright-core/src/utils/isomorphic/protocolMetainfo.ts	Marks `Page.setDockTile` as internal in protocol metainfo.
packages/playwright-core/src/server/webkit/wkPage.ts	Adds required `setDockTile` stub to WebKit delegate.
packages/playwright-core/src/server/trace/viewer/traceViewer.ts	Removes `openUrlInApp` helper.
packages/playwright-core/src/server/page.ts	Extends `PageDelegate` and `Page` with `setDockTile`.
packages/playwright-core/src/server/index.ts	Stops exporting `openUrlInApp` and `ProgressController` from server index.
packages/playwright-core/src/server/firefox/ffPage.ts	Adds required `setDockTile` stub to Firefox delegate.
packages/playwright-core/src/server/dispatchers/pageDispatcher.ts	Exposes `Page.setDockTile` over the wire.
packages/playwright-core/src/server/devtoolsController.ts	Changes DevTools endpoint to return a ws URL and removes static-file routing.
packages/playwright-core/src/server/chromium/crPage.ts	Implements `setDockTile` via CDP `Browser.setDockTile`.
packages/playwright-core/src/server/browserContext.ts	Minor refactor of `devtoolsStart` return.
packages/playwright-core/src/server/bidi/bidiPage.ts	Adds required `setDockTile` stub to BiDi delegate.
packages/playwright-core/src/protocol/validator.ts	Adds validation schema for `PageSetDockTile`.
packages/playwright-core/src/client/page.ts	Adds internal client helper `_setDockTile`.
packages/devtools/src/devtools.tsx	Changes transport initialization to read a full ws URL from `?ws=`.
package.json	Removes `@trayjs/trayjs` dependency.
package-lock.json	Removes `@trayjs/*` packages from lockfile.

Comments suppressed due to low confidence (1)

packages/playwright/src/mcp/browser/tools/devtools.ts:33

The tool schema exposes an optional guid parameter, but the underlying protocol/server BrowserContext.devtoolsStart does not accept/consume it (it will be silently dropped by protocol validation). Either remove guid from the tool schema, or plumb it through to DevToolsController.start() so callers can request a deterministic endpoint path.

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Copilot · 2026-02-11T19:53:11Z

packages/playwright/src/mcp/terminal/devtoolsApp.ts

+        reject(new Error('already running'));
+      });
+      client.on('error', () => {
+        fs.unlinkSync(socketPath);


fs.unlinkSync(socketPath) in the client.on('error') path can throw (e.g. on Windows named pipes, or if the socket path doesn't exist / is already removed). This would prevent recovery from a stale socket. Guard this unlink (platform check + exists + try/catch) before re-listening.

Suggested change

fs.unlinkSync(socketPath);

// Attempt to clean up a stale Unix domain socket; on Windows the path is a named pipe.

if (process.platform !== 'win32') {

try {

if (fs.existsSync(socketPath))

fs.unlinkSync(socketPath);

} catch {

// Ignore cleanup errors and still attempt to re-listen.

}

}

Copilot · 2026-02-11T19:53:11Z

packages/devtools/src/devtools.tsx

-    const wsProtocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
-    const guid = new URLSearchParams(location.search).get('ws');
-    const transport = new DevToolsTransport(wsProtocol + '//' + location.host + '/' + guid);
+    const wsUrl = new URLSearchParams(location.search).get('ws')!;


This code assumes the ws query parameter is always present (get('ws')!). devtoolsApp currently navigates to the UI without that param, and users can also open the page directly, so this will throw at runtime. Handle a missing/invalid ws parameter by showing a clear disconnected/error state instead of crashing (and consider validating that it’s a ws/wss URL).

Suggested change

const wsUrl = new URLSearchParams(location.search).get('ws')!;

const searchParams = new URLSearchParams(location.search);

const wsUrl = searchParams.get('ws');

const isValidWsUrl = typeof wsUrl === 'string' && /^wss?:\/\//.test(wsUrl);

if (!isValidWsUrl) {

setStatus({ text: 'Disconnected: missing or invalid "ws" query parameter', cls: 'error' });

return;

}

Copilot · 2026-02-11T19:53:11Z

packages/playwright/src/mcp/terminal/devtoolsApp.ts

+  const url = httpServer.urlPrefix('human-readable');
+
+  const { page } = await launchApp('devtools');
+  await page.goto(url);
+  return page;


openDevToolsApp() navigates to the DevTools UI without providing the required ws query parameter, but packages/devtools/src/devtools.tsx now assumes ?ws=<wsUrl> is always present. As a result, the app will fail to connect (or crash) when launched this way. Consider passing the WebSocket endpoint into devtoolsApp (e.g. via argv/env or by discovering/running browser_devtools_start) and navigating to index.html?ws=${encodeURIComponent(wsUrl)}.

Copilot · 2026-02-11T19:53:12Z

packages/playwright/src/mcp/terminal/devtoolsApp.ts

+async function acquireSingleton(): Promise<net.Server> {
+  const socketPath = devtoolsSocketPath();
+
+  return await new Promise((resolve, reject) => {
+    const server = net.createServer();
+    server.listen(socketPath, () => resolve(server));
+    server.on('error', (err: NodeJS.ErrnoException) => {


On Unix, net.Server.listen(socketPath) will fail if the parent directory of the socket file does not exist. devtoolsSocketPath() uses a temp subdirectory but acquireSingleton() does not ensure it exists. Create the sockets directory (e.g. fs.mkdirSync(socketsDirectory(), { recursive: true })) before calling listen() on non-Windows platforms.

github-actions · 2026-02-12T04:44:51Z

Test results for "MCP"

1 failed
❌ [chrome] › mcp/cli-webstorage.spec.ts:20 › localstorage-list shows no items when empty @mcp-macos-15

4791 passed, 135 skipped

Merge workflow run.

github-actions · 2026-02-12T05:27:39Z

Test results for "tests 1"

5 failed
❌ [playwright-test] › expect.spec.ts:582 › should log scale the time @macos-latest-node20
❌ [playwright-test] › global-setup.spec.ts:313 › globalSetup should work for auth @macos-latest-node20
❌ [playwright-test] › playwright.artifacts.spec.ts:127 › should work with screenshot: on @macos-latest-node20
❌ [playwright-test] › reporter.spec.ts:251 › merged › should not have internal error when steps are finished after timeout @macos-latest-node20
❌ [playwright-test] › ui-mode-test-network-tab.spec.ts:301 › should copy network request @macos-latest-node20

2 flaky

⚠️ [playwright-test] › ui-mode-trace.spec.ts:700 › should indicate current test status `@macos-latest-node20`
⚠️ [playwright-test] › ui-mode-trace.spec.ts:700 › should indicate current test status `@windows-latest-node20`

38518 passed, 843 skipped

Merge workflow run.

yury-s approved these changes Feb 11, 2026

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yury-s requested a review from Copilot February 11, 2026 19:46

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pavelfeldman force-pushed the one_frontend branch 2 times, most recently from ad7d672 to a35421b Compare February 12, 2026 01:15

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pavelfeldman force-pushed the one_frontend branch from a35421b to e7bcc7c Compare February 12, 2026 01:22

chore: prep devtools app

7490669

pavelfeldman force-pushed the one_frontend branch from e7bcc7c to 7490669 Compare February 12, 2026 01:32

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pavelfeldman merged commit 6d35c8b into microsoft:main Feb 12, 2026
30 of 34 checks passed

This was referenced Feb 12, 2026

[Ports]: Backport client side changes for 1.59 microsoft/playwright-python#3027

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[Ports]: Backport client side changes for 1.59 microsoft/playwright-java#1884

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[Ports]: Backport client side changes for 1.59 microsoft/playwright-dotnet#3274

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chore: prep devtools app#39231

chore: prep devtools app#39231
pavelfeldman merged 1 commit intomicrosoft:mainfrom
pavelfeldman:one_frontend

pavelfeldman commented Feb 11, 2026

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-        fs.unlinkSync(socketPath);
+        // Attempt to clean up a stale Unix domain socket; on Windows the path is a named pipe.
+        if (process.platform !== 'win32') {
+          try {
+            if (fs.existsSync(socketPath))
+              fs.unlinkSync(socketPath);
+          } catch {
+            // Ignore cleanup errors and still attempt to re-listen.
+          }
+        }

-    const wsUrl = new URLSearchParams(location.search).get('ws')!;
+    const searchParams = new URLSearchParams(location.search);
+    const wsUrl = searchParams.get('ws');
+    const isValidWsUrl = typeof wsUrl === 'string' && /^wss?:\/\//.test(wsUrl);
+    if (!isValidWsUrl) {
+      setStatus({ text: 'Disconnected: missing or invalid "ws" query parameter', cls: 'error' });
+      return;
+    }

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Pull request overview

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github-actions bot commented Feb 12, 2026

Test results for "MCP"

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github-actions bot commented Feb 12, 2026

Test results for "tests 1"

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