Fix Markdown tests on windows (microsoft#153212)

Fix windows tests

Author: mjbvz

extensions/markdown-language-features/src/languageFeatures/pathCompletions.ts

@@ -9,7 +9,6 @@ import { IMdParser } from '../markdownEngine';
 import { TableOfContents } from '../tableOfContents';
 import { ITextDocument } from '../types/textDocument';
 import { resolveUriToMarkdownFile } from '../util/openDocumentLink';
-import { Schemes } from '../util/schemes';
 import { IMdWorkspace } from '../workspace';
 import { MdLinkProvider } from './documentLinks';
 
@@ -325,7 +324,7 @@ export class MdVsCodePathCompletionProvider implements vscode.CompletionItemProv
 
 	private resolvePath(root: vscode.Uri, ref: string): vscode.Uri | undefined {
 		try {
-			if (root.scheme === Schemes.file) {
+			if (root.scheme === 'file') {
 				return vscode.Uri.file(resolve(dirname(root.fsPath), ref));
 			} else {
 				return root.with({

extensions/markdown-language-features/src/test/inMemoryWorkspace.ts

@@ -4,6 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as assert from 'assert';
+import * as path from 'path';
 import * as vscode from 'vscode';
 import { ITextDocument } from '../types/textDocument';
 import { ResourceMap } from '../util/resourceMap';
@@ -37,11 +38,11 @@ export class InMemoryMdWorkspace implements IMdWorkspace {
 
 	public async readDirectory(resource: vscode.Uri): Promise<[string, vscode.FileType][]> {
 		const files = new Map<string, vscode.FileType>();
-		const pathPrefix = resource.fsPath + (resource.fsPath.endsWith('/') ? '' : '/');
+		const pathPrefix = resource.fsPath + (resource.fsPath.endsWith('/') || resource.fsPath.endsWith('\\') ? '' : path.sep);
 		for (const doc of this._documents.values()) {
 			const path = doc.uri.fsPath;
 			if (path.startsWith(pathPrefix)) {
-				const parts = path.slice(pathPrefix.length).split('/');
+				const parts = path.slice(pathPrefix.length).split(/\/|\\/g);
 				files.set(parts[0], parts.length > 1 ? vscode.FileType.Directory : vscode.FileType.File);
 			}
 		}