From 6d6b1a384bb0f29a6c62a8382b36560da4226f4e Mon Sep 17 00:00:00 2001
From: Pavel Feldman <pavel.feldman@gmail.com>
Date: Wed, 30 Apr 2025 08:41:19 -0700
Subject: [PATCH] chore: fix merge config (#311)

---
 src/config.ts        | 27 ++++++++++++++++--------
 src/program.ts       |  1 +
 tests/fixtures.ts    | 10 ++++-----
 tests/headed.spec.ts | 49 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+), 14 deletions(-)
 create mode 100644 tests/headed.spec.ts

diff --git a/src/config.ts b/src/config.ts
index 4ad8697..0d4ad7a 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -89,7 +89,7 @@ export async function configFromCLIOptions(cliOptions: CLIOptions): Promise<Conf
   const launchOptions: LaunchOptions = {
     channel,
     executablePath: cliOptions.executablePath,
-    headless: cliOptions.headless ?? false,
+    headless: cliOptions.headless,
   };
 
   if (browserName === 'chromium')
@@ -158,24 +158,33 @@ export async function outputFile(config: Config, name: string): Promise<string>
   return path.join(result, fileName);
 }
 
+function pickDefined<T extends object>(obj: T | undefined): Partial<T> {
+  return Object.fromEntries(
+      Object.entries(obj ?? {}).filter(([_, v]) => v !== undefined)
+  ) as Partial<T>;
+}
+
 function mergeConfig(base: Config, overrides: Config): Config {
   const browser: Config['browser'] = {
-    ...base.browser,
-    ...overrides.browser,
+    ...pickDefined(base.browser),
+    ...pickDefined(overrides.browser),
     launchOptions: {
-      ...base.browser?.launchOptions,
-      ...overrides.browser?.launchOptions,
+      ...pickDefined(base.browser?.launchOptions),
+      ...pickDefined(overrides.browser?.launchOptions),
       ...{ assistantMode: true },
     },
     contextOptions: {
-      ...base.browser?.contextOptions,
-      ...overrides.browser?.contextOptions,
+      ...pickDefined(base.browser?.contextOptions),
+      ...pickDefined(overrides.browser?.contextOptions),
     },
   };
 
+  if (browser.browserName !== 'chromium')
+    delete browser.launchOptions.channel;
+
   return {
-    ...base,
-    ...overrides,
+    ...pickDefined(base),
+    ...pickDefined(overrides),
     browser,
   };
 }
diff --git a/src/program.ts b/src/program.ts
index 6a09ced..c97fcfe 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -41,6 +41,7 @@ program
     .option('--config <path>', 'Path to the configuration file.')
     .action(async options => {
       const config = await resolveConfig(options);
+      console.error(config);
       const serverList = new ServerList(() => createServer(config));
       setupExitWatchdog(serverList);
 
diff --git a/tests/fixtures.ts b/tests/fixtures.ts
index 4027b2c..adfda76 100644
--- a/tests/fixtures.ts
+++ b/tests/fixtures.ts
@@ -34,11 +34,11 @@ type TestFixtures = {
   cdpEndpoint: string;
   server: TestServer;
   httpsServer: TestServer;
+  mcpHeadless: boolean;
+  mcpBrowser: string | undefined;
 };
 
 type WorkerFixtures = {
-  mcpHeadless: boolean;
-  mcpBrowser: string | undefined;
   _workerServers: { server: TestServer, httpsServer: TestServer };
 };
 
@@ -112,11 +112,11 @@ export const test = baseTest.extend<TestFixtures, WorkerFixtures>({
     browserProcess.kill();
   },
 
-  mcpHeadless: [async ({ headless }, use) => {
+  mcpHeadless: async ({ headless }, use) => {
     await use(headless);
-  }, { scope: 'worker' }],
+  },
 
-  mcpBrowser: ['chrome', { option: true, scope: 'worker' }],
+  mcpBrowser: ['chrome', { option: true }],
 
   _workerServers: [async ({}, use, workerInfo) => {
     const port = 8907 + workerInfo.workerIndex * 4;
diff --git a/tests/headed.spec.ts b/tests/headed.spec.ts
new file mode 100644
index 0000000..04954c1
--- /dev/null
+++ b/tests/headed.spec.ts
@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { test, expect } from './fixtures';
+
+for (const mcpHeadless of [false, true]) {
+  test.describe(`mcpHeadless: ${mcpHeadless}`, () => {
+    test.use({ mcpHeadless });
+    test.skip(process.platform === 'linux', 'Auto-detection wont let this test run on linux');
+    test('browser', async ({ client, server, mcpBrowser }) => {
+      test.skip(!['chrome', 'msedge', 'chromium'].includes(mcpBrowser ?? ''), 'Only chrome is supported for this test');
+      server.route('/', (req, res) => {
+        res.writeHead(200, { 'Content-Type': 'text/html' });
+        res.end(`
+          <body></body>
+          <script>
+            document.body.textContent = navigator.userAgent;
+          </script>
+        `);
+      });
+
+      const response = await client.callTool({
+        name: 'browser_navigate',
+        arguments: {
+          url: server.PREFIX,
+        },
+      });
+
+      expect(response).toContainTextContent(`Mozilla/5.0`);
+      if (mcpHeadless)
+        expect(response).toContainTextContent(`HeadlessChrome`);
+      else
+        expect(response).not.toContainTextContent(`HeadlessChrome`);
+    });
+  });
+}