Keep rootDir as commonjs.

Author: goodov

build/commands/lib/config.js

@@ -9,23 +9,13 @@ import os from 'os'
 import path from 'path'
 import fs from 'fs'
 import assert from 'assert'
+import rootDir from './rootDir.cjs'
 import EnvConfig from './envConfig.js'
 import Log from './logging.js'
 import util from './util.js'
 
-let dirName = import.meta.dirname
-// Use fs.realpathSync to normalize the path(__dirname could be c:\.. or C:\..).
-if (process.platform === 'win32') {
-  dirName = fs.realpathSync.native(dirName)
-}
-const rootDir = path.resolve(dirName, '..', '..', '..', '..', '..')
 const braveCoreDir = path.join(rootDir, 'src', 'brave')
 
-if (rootDir.includes(' ')) {
-  Log.error(`Root directory contains spaces, this is not supported: ${rootDir}`)
-  process.exit(1)
-}
-
 const envConfig = new EnvConfig(braveCoreDir)
 
 const getEnvConfig = (keyPath, defaultValue = undefined) => {

build/commands/lib/rootDir.cjs

@@ -0,0 +1,27 @@
+// Copyright (c) 2026 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+// This is a CommonJS module so we can use __dirname to resolve the root
+// directory. The rest of the codebase is ESM, which would require
+// import.meta.dirname for this, but that isn't supported by Jest.
+
+const fs = require('fs')
+const path = require('path')
+
+let dirName = __dirname
+// Use fs.realpathSync to normalize the path(__dirname could be c:\.. or C:\..).
+if (process.platform === 'win32') {
+  dirName = fs.realpathSync.native(dirName)
+}
+
+const rootDir = path.resolve(dirName, '..', '..', '..', '..', '..')
+if (rootDir.includes(' ')) {
+  console.error(
+    `Root directory contains spaces, this is not supported: ${rootDir}`,
+  )
+  process.exit(1)
+}
+
+module.exports = rootDir