use path primitives when compute workspace relative path, fixes #10446

src/vs/base/test/common/paths.test.ts

@@ -13,6 +13,7 @@ suite('Paths', () => {
 		assert.equal(paths.relative('/test/api/files/test', '/test/api/files/lib/foo'), '../lib/foo');
 		assert.equal(paths.relative('far/boo', 'boo/far'), '../../boo/far');
 		assert.equal(paths.relative('far/boo', 'far/boo'), '');
+		assert.equal(paths.relative('far/boo', 'far/boo/bar/foo'), 'bar/foo');
 	});
 
 	test('dirname', () => {

src/vs/workbench/api/node/extHostWorkspace.ts

@@ -5,6 +5,7 @@
 'use strict';
 
 import URI from 'vs/base/common/uri';
+import {relative, isEqualOrParent} from 'vs/base/common/paths';
 import {IThreadService} from 'vs/workbench/services/thread/common/threadService';
 import {IResourceEdit} from 'vs/editor/common/services/bulkEdit';
 import {TPromise} from 'vs/base/common/winjs.base';
@@ -28,7 +29,7 @@ export class ExtHostWorkspace {
 		return this._workspacePath;
 	}
 
-	getRelativePath(pathOrUri: string|Uri): string {
+	getRelativePath(pathOrUri: string | Uri): string {
 
 		let path: string;
 		if (typeof pathOrUri === 'string') {
@@ -37,9 +38,8 @@ export class ExtHostWorkspace {
 			path = pathOrUri.fsPath;
 		}
 
-		if (this._workspacePath && this._workspacePath.length < path.length) {
-			// return relative(workspacePath, path);
-			return path.substring(this._workspacePath.length);
+		if (isEqualOrParent(path, this._workspacePath)) {
+			return relative(this._workspacePath, path);
 		}
 
 		return path;

src/vs/workbench/test/node/api/extHostWorkspace.test.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import * as assert from 'assert';
+import {ExtHostWorkspace} from 'vs/workbench/api/node/extHostWorkspace';
+import {TestThreadService} from './testThreadService';
+
+suite('ExtHostWorkspace', function () {
+
+	test('asRelativePath', function () {
+
+		const ws = new ExtHostWorkspace(new TestThreadService(), 'm:/Coding/Applications/NewsWoWBot');
+
+		assert.equal(ws.getRelativePath('m:/Coding/Applications/NewsWoWBot/bernd/das/brot'), 'bernd/das/brot');
+		assert.equal(ws.getRelativePath('m:/Apps/DartPubCache/hosted/pub.dartlang.org/convert-2.0.1/lib/src/hex.dart'),
+			'm:/Apps/DartPubCache/hosted/pub.dartlang.org/convert-2.0.1/lib/src/hex.dart');
+
+	});
+});