diff --git a/build/build.js b/build/build.js
index a59d5fa5..045e6a18 100644
--- a/build/build.js
+++ b/build/build.js
@@ -6,7 +6,8 @@
 //@ts-check
 
 const glob = require('glob');
-const { copyFile, removeDir, tsc, dts, buildESM, buildAMD } = require('../build/utils');
+const { tsc, dts, buildESM, buildAMD } = require('../build/utils');
+const { copyFile, removeDir } = require('../build/fs');
 
 removeDir(`out`);
 
diff --git a/build/fs.js b/build/fs.js
new file mode 100644
index 00000000..b0cdcebe
--- /dev/null
+++ b/build/fs.js
@@ -0,0 +1,98 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+const fs = require('fs');
+const path = require('path');
+
+const REPO_ROOT = path.join(__dirname, '../');
+
+const existingDirCache = new Set();
+/**
+ * @param {string} dirname
+ */
+function ensureDir(dirname) {
+	/** @type {string[]} */
+	const dirs = [];
+
+	while (dirname.length > REPO_ROOT.length) {
+		dirs.push(dirname);
+		dirname = path.dirname(dirname);
+	}
+	dirs.reverse();
+	dirs.forEach((dir) => {
+		if (!existingDirCache.has(dir)) {
+			try {
+				fs.mkdirSync(dir);
+			} catch (err) {}
+			existingDirCache.add(dir);
+		}
+	});
+}
+exports.ensureDir = ensureDir;
+
+/**
+ * Copy a file.
+ *
+ * @param {string} _source
+ * @param {string} _destination
+ */
+function copyFile(_source, _destination) {
+	const source = path.join(REPO_ROOT, _source);
+	const destination = path.join(REPO_ROOT, _destination);
+
+	ensureDir(path.dirname(destination));
+	fs.writeFileSync(destination, fs.readFileSync(source));
+
+	console.log(`Copied ${_source} to ${_destination}`);
+}
+exports.copyFile = copyFile;
+
+/**
+ * Remove a directory and all its contents.
+ *
+ * @param {string} _dirPath
+ * @param {((filename:string)=>boolean)} [keep]
+ */
+function removeDir(_dirPath, keep) {
+	if (typeof keep === 'undefined') {
+		keep = () => false;
+	}
+	const dirPath = path.join(REPO_ROOT, _dirPath);
+	if (!fs.existsSync(dirPath)) {
+		return;
+	}
+	rmDir(dirPath, _dirPath);
+	console.log(`Deleted ${_dirPath}`);
+
+	/**
+	 * @param {string} dirPath
+	 * @param {string} relativeDirPath
+	 * @returns {boolean}
+	 */
+	function rmDir(dirPath, relativeDirPath) {
+		let keepsFiles = false;
+		const entries = fs.readdirSync(dirPath);
+		for (const entry of entries) {
+			const filePath = path.join(dirPath, entry);
+			const relativeFilePath = path.join(relativeDirPath, entry);
+			if (keep(relativeFilePath)) {
+				keepsFiles = true;
+				continue;
+			}
+			if (fs.statSync(filePath).isFile()) {
+				fs.unlinkSync(filePath);
+			} else {
+				keepsFiles = rmDir(filePath, relativeFilePath) || keepsFiles;
+			}
+		}
+		if (!keepsFiles) {
+			fs.rmdirSync(dirPath);
+		}
+		return keepsFiles;
+	}
+}
+exports.removeDir = removeDir;
diff --git a/build/release.js b/build/release.js
index 6abee52e..5761bd2b 100644
--- a/build/release.js
+++ b/build/release.js
@@ -15,7 +15,8 @@
 
 const path = require('path');
 const fs = require('fs');
-const { REPO_ROOT, removeDir, readFiles, writeFiles } = require('../build/utils');
+const { REPO_ROOT, readFiles, writeFiles } = require('../build/utils');
+const { removeDir } = require('../build/fs');
 const ts = require('typescript');
 /**@type { IMetadata } */
 const metadata = require('../metadata.js');
diff --git a/build/releaseMetadata.js b/build/releaseMetadata.js
index 37598a55..555d251d 100644
--- a/build/releaseMetadata.js
+++ b/build/releaseMetadata.js
@@ -8,7 +8,8 @@
 const glob = require('glob');
 const path = require('path');
 const fs = require('fs');
-const { REPO_ROOT, prettier, ensureDir } = require('./utils');
+const { REPO_ROOT } = require('./utils');
+const { ensureDir } = require('./fs');
 
 const customFeatureLabels = {
 	'vs/editor/browser/controller/coreCommands': 'coreCommands',
diff --git a/build/simpleserver.js b/build/simpleserver.js
index 5d6cfe02..250ea8b4 100644
--- a/build/simpleserver.js
+++ b/build/simpleserver.js
@@ -9,7 +9,8 @@ const fs = require('fs');
 const path = require('path');
 const http = require('http');
 const yaserver = require('yaserver');
-const { REPO_ROOT, ensureDir } = require('./utils');
+const { REPO_ROOT } = require('./utils');
+const { ensureDir } = require('./fs');
 
 const WEBSITE_GENERATED_PATH = path.join(REPO_ROOT, 'website/playground/new-samples');
 
diff --git a/build/utils.js b/build/utils.js
index 052b65eb..932956a4 100644
--- a/build/utils.js
+++ b/build/utils.js
@@ -12,82 +12,11 @@ const esbuild = require('esbuild');
 /** @type {any} */
 const alias = require('esbuild-plugin-alias');
 const glob = require('glob');
+const { ensureDir } = require('./fs');
 
 const REPO_ROOT = path.join(__dirname, '../');
 exports.REPO_ROOT = REPO_ROOT;
 
-const existingDirCache = new Set();
-/**
- * @param {string} dirname
- */
-function ensureDir(dirname) {
-	/** @type {string[]} */
-	const dirs = [];
-
-	while (dirname.length > REPO_ROOT.length) {
-		dirs.push(dirname);
-		dirname = path.dirname(dirname);
-	}
-	dirs.reverse();
-	dirs.forEach((dir) => {
-		if (!existingDirCache.has(dir)) {
-			try {
-				fs.mkdirSync(dir);
-			} catch (err) {}
-			existingDirCache.add(dir);
-		}
-	});
-}
-exports.ensureDir = ensureDir;
-
-/**
- * Copy a file.
- *
- * @param {string} _source
- * @param {string} _destination
- */
-function copyFile(_source, _destination) {
-	const source = path.join(REPO_ROOT, _source);
-	const destination = path.join(REPO_ROOT, _destination);
-
-	ensureDir(path.dirname(destination));
-	fs.writeFileSync(destination, fs.readFileSync(source));
-
-	console.log(`Copied ${_source} to ${_destination}`);
-}
-exports.copyFile = copyFile;
-
-/**
- * Remove a directory and all its contents.
- *
- * @param {string} _dirPath
- */
-function removeDir(_dirPath) {
-	const dirPath = path.join(REPO_ROOT, _dirPath);
-	if (!fs.existsSync(dirPath)) {
-		return;
-	}
-	rmDir(dirPath);
-	console.log(`Deleted ${_dirPath}`);
-
-	/**
-	 * @param {string} dirPath
-	 */
-	function rmDir(dirPath) {
-		const entries = fs.readdirSync(dirPath);
-		for (const entry of entries) {
-			const filePath = path.join(dirPath, entry);
-			if (fs.statSync(filePath).isFile()) {
-				fs.unlinkSync(filePath);
-			} else {
-				rmDir(filePath);
-			}
-		}
-		fs.rmdirSync(dirPath);
-	}
-}
-exports.removeDir = removeDir;
-
 /**
  * Launch the typescript compiler synchronously over a project.
  *
diff --git a/build/website.js b/build/website.js
index 5b92cba5..48c343ce 100644
--- a/build/website.js
+++ b/build/website.js
@@ -12,7 +12,8 @@ const path = require('path');
 const fs = require('fs');
 const cp = require('child_process');
 const CleanCSS = require('clean-css');
-const { REPO_ROOT, removeDir, readFiles, writeFiles } = require('./utils');
+const { REPO_ROOT, readFiles, writeFiles } = require('./utils');
+const { removeDir } = require('./fs');
 
 /** @type {string} */
 const MONACO_EDITOR_VERSION = (() => {
diff --git a/samples/browser-esm-esbuild/build.js b/samples/browser-esm-esbuild/build.js
index 14bad23a..85213842 100644
--- a/samples/browser-esm-esbuild/build.js
+++ b/samples/browser-esm-esbuild/build.js
@@ -1,8 +1,15 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
 const esbuild = require('esbuild');
 const path = require('path');
-const { removeDir } = require('../../build/utils');
+const { removeDir } = require('../../build/fs');
 
-removeDir(path.join(__dirname, 'dist'));
+removeDir('samples/browser-esm-esbuild/dist', (entry) => /index.html$/.test(entry));
 
 const workerEntryPoints = [
 	'vs/language/json/json.worker.js',