Merge from vscode 2cfc8172e533e50c90e6a3152f6bfb1f82f963f3 (#6516)

* Merge from vscode 2cfc8172e533e50c90e6a3152f6bfb1f82f963f3

* fix tests

test/tree/tree.js

@@ -0,0 +1,24 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+const path = require('path');
+const fs = require('fs');
+
+function collect(location) {
+	const element = { name: path.basename(location) };
+	const stat = fs.statSync(location);
+
+	if (!stat.isDirectory()) {
+		return { element, incompressible: true };
+	}
+
+	const children = fs.readdirSync(location)
+		.map(child => path.join(location, child))
+		.map(collect);
+
+	return { element, children };
+}
+
+console.log(JSON.stringify(collect(process.cwd())));