fix: do not set channel if executablePath is provided

scripts/generate-docs.ts

@@ -10,7 +10,7 @@ import {Client} from '@modelcontextprotocol/sdk/client/index.js';
 import {StdioClientTransport} from '@modelcontextprotocol/sdk/client/stdio.js';
 import type {Tool} from '@modelcontextprotocol/sdk/types.js';
 
-import {cliOptions} from '../build/src/main.js';
+import {cliOptions} from '../build/src/cli.js';
 import {ToolCategories} from '../build/src/tools/categories.js';
 
 const MCP_SERVER_PATH = 'build/src/index.js';

src/cli.ts

@@ -0,0 +1,89 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import yargs from 'yargs';
+import {hideBin} from 'yargs/helpers';
+
+export const cliOptions = {
+  browserUrl: {
+    type: 'string' as const,
+    description:
+      'Connect to a running Chrome instance using port forwarding. For more details see: https://developer.chrome.com/docs/devtools/remote-debugging/local-server.',
+    alias: 'u',
+    coerce: (url: string) => {
+      new URL(url);
+      return url;
+    },
+  },
+  headless: {
+    type: 'boolean' as const,
+    description: 'Whether to run in headless (no UI) mode.',
+    default: false,
+  },
+  executablePath: {
+    type: 'string' as const,
+    description: 'Path to custom Chrome executable.',
+    conflicts: 'browserUrl',
+    alias: 'e',
+  },
+  isolated: {
+    type: 'boolean' as const,
+    description:
+      'If specified, creates a temporary user-data-dir that is automatically cleaned up after the browser is closed.',
+    default: false,
+  },
+  customDevtools: {
+    type: 'string' as const,
+    description: 'Path to custom DevTools.',
+    hidden: true,
+    conflicts: 'browserUrl',
+    alias: 'd',
+  },
+  channel: {
+    type: 'string' as const,
+    description:
+      'Specify a different Chrome channel that should be used. The default is the stable channel version.',
+    choices: ['stable', 'canary', 'beta', 'dev'] as const,
+    conflicts: ['browserUrl', 'executablePath'],
+  },
+  logFile: {
+    type: 'string' as const,
+    describe: 'Save the logs to file.',
+    hidden: true,
+  },
+};
+
+export function parseArguments(version: string, argv = process.argv) {
+  const yargsInstance = yargs(hideBin(argv))
+    .scriptName('npx chrome-devtools-mcp@latest')
+    .options(cliOptions)
+    .check(args => {
+      // We can't set default in the options else
+      // Yargs will complain
+      if (!args.channel && !args.browserUrl && !args.executablePath) {
+        args.channel = 'stable';
+      }
+      return true;
+    })
+    .example([
+      [
+        '$0 --browserUrl http://127.0.0.1:9222',
+        'Connect to an existing browser instance',
+      ],
+      ['$0 --channel beta', 'Use Chrome Beta installed on this system'],
+      ['$0 --channel canary', 'Use Chrome Canary installed on this system'],
+      ['$0 --channel dev', 'Use Chrome Dev installed on this system'],
+      ['$0 --channel stable', 'Use stable Chrome installed on this system'],
+      ['$0 --logFile /tmp/log.txt', 'Save logs to a file'],
+      ['$0 --help', 'Print CLI options'],
+    ]);
+
+  return yargsInstance
+    .wrap(Math.min(120, yargsInstance.terminalWidth()))
+    .help()
+    .version(version)
+    .parseSync();
+}

src/main.ts

@@ -12,11 +12,10 @@ import {McpServer} from '@modelcontextprotocol/sdk/server/mcp.js';
 import {StdioServerTransport} from '@modelcontextprotocol/sdk/server/stdio.js';
 import type {CallToolResult} from '@modelcontextprotocol/sdk/types.js';
 import {SetLevelRequestSchema} from '@modelcontextprotocol/sdk/types.js';
-import yargs from 'yargs';
-import {hideBin} from 'yargs/helpers';
 
 import type {Channel} from './browser.js';
 import {resolveBrowser} from './browser.js';
+import {parseArguments} from './cli.js';
 import {logger, saveLogsToFile} from './logger.js';
 import {McpContext} from './McpContext.js';
 import {McpResponse} from './McpResponse.js';
@@ -32,55 +31,6 @@ import * as scriptTools from './tools/script.js';
 import * as snapshotTools from './tools/snapshot.js';
 import type {ToolDefinition} from './tools/ToolDefinition.js';
 
-export const cliOptions = {
-  browserUrl: {
-    type: 'string' as const,
-    description:
-      'Connect to a running Chrome instance using port forwarding. For more details see: https://developer.chrome.com/docs/devtools/remote-debugging/local-server.',
-    alias: 'u',
-    coerce: (url: string) => {
-      new URL(url);
-      return url;
-    },
-  },
-  headless: {
-    type: 'boolean' as const,
-    description: 'Whether to run in headless (no UI) mode.',
-    default: false,
-  },
-  executablePath: {
-    type: 'string' as const,
-    description: 'Path to custom Chrome executable.',
-    conflicts: 'browserUrl',
-    alias: 'e',
-  },
-  isolated: {
-    type: 'boolean' as const,
-    description:
-      'If specified, creates a temporary user-data-dir that is automatically cleaned up after the browser is closed.',
-    default: false,
-  },
-  customDevtools: {
-    type: 'string' as const,
-    description: 'Path to custom DevTools.',
-    hidden: true,
-    conflicts: 'browserUrl',
-    alias: 'd',
-  },
-  channel: {
-    type: 'string' as const,
-    description:
-      'Specify a different Chrome channel that should be used. The default is the stable channel version.',
-    choices: ['stable', 'canary', 'beta', 'dev'] as const,
-    conflicts: ['browserUrl', 'executablePath'],
-  },
-  logFile: {
-    type: 'string' as const,
-    describe: 'Save the logs to file.',
-    hidden: true,
-  },
-};
-
 function readPackageJson(): {version?: string} {
   const currentDir = import.meta.dirname;
   const packageJsonPath = path.join(currentDir, '..', '..', 'package.json');
@@ -98,35 +48,7 @@ function readPackageJson(): {version?: string} {
 
 const version = readPackageJson().version ?? 'unknown';
 
-const yargsInstance = yargs(hideBin(process.argv))
-  .scriptName('npx chrome-devtools-mcp@latest')
-  .options(cliOptions)
-  .check(args => {
-    // We can't set default in the options else
-    // Yargs will complain
-    if (!args.channel && !args.browserUrl) {
-      args.channel = 'stable';
-    }
-    return true;
-  })
-  .example([
-    [
-      '$0 --browserUrl http://127.0.0.1:9222',
-      'Connect to an existing browser instance',
-    ],
-    ['$0 --channel beta', 'Use Chrome Beta installed on this system'],
-    ['$0 --channel canary', 'Use Chrome Canary installed on this system'],
-    ['$0 --channel dev', 'Use Chrome Dev installed on this system'],
-    ['$0 --channel stable', 'Use stable Chrome installed on this system'],
-    ['$0 --logFile /tmp/log.txt', 'Save logs to a file'],
-    ['$0 --help', 'Print CLI options'],
-  ]);
-
-export const args = yargsInstance
-  .wrap(Math.min(120, yargsInstance.terminalWidth()))
-  .help()
-  .version(version)
-  .parseSync();
+export const args = parseArguments(version);
 
 const logFile = args.logFile ? saveLogsToFile(args.logFile) : undefined;
 

tests/cli.test.ts

@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import assert from 'node:assert';
+import {describe, it} from 'node:test';
+
+import {parseArguments} from '../src/cli.js';
+
+describe('cli args parsing', () => {
+  it('parses with default args', async () => {
+    const args = parseArguments('1.0.0', ['node', 'main.js']);
+    assert.deepStrictEqual(args, {
+      _: [],
+      headless: false,
+      isolated: false,
+      $0: 'npx chrome-devtools-mcp@latest',
+      channel: 'stable',
+    });
+  });
+
+  it('parses with browser url', async () => {
+    const args = parseArguments('1.0.0', [
+      'node',
+      'main.js',
+      '--browserUrl',
+      'http://localhost:3000',
+    ]);
+    assert.deepStrictEqual(args, {
+      _: [],
+      headless: false,
+      isolated: false,
+      $0: 'npx chrome-devtools-mcp@latest',
+      'browser-url': 'http://localhost:3000',
+      browserUrl: 'http://localhost:3000',
+      u: 'http://localhost:3000',
+    });
+  });
+
+  it('parses with executable path', async () => {
+    const args = parseArguments('1.0.0', [
+      'node',
+      'main.js',
+      '--executablePath',
+      '/tmp/test 123/chrome',
+    ]);
+    assert.deepStrictEqual(args, {
+      _: [],
+      headless: false,
+      isolated: false,
+      $0: 'npx chrome-devtools-mcp@latest',
+      'executable-path': '/tmp/test 123/chrome',
+      e: '/tmp/test 123/chrome',
+      executablePath: '/tmp/test 123/chrome',
+    });
+  });
+});