Fix markdown preview in serverless

For #99717

extensions/markdown-language-features/src/features/previewContentProvider.ts

@@ -111,7 +111,7 @@ export class MarkdownContentProvider {
 
 	private extensionResourcePath(resourceProvider: WebviewResourceProvider, mediaFile: string): string {
 		const webviewResource = resourceProvider.asWebviewUri(
-			vscode.Uri.file(this.context.asAbsolutePath(path.join('media', mediaFile))));
+			vscode.Uri.joinPath(this.context.extensionUri, 'media', mediaFile));
 		return webviewResource.toString();
 	}
 

extensions/markdown-language-features/src/markdownExtensions.ts

@@ -4,12 +4,11 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as vscode from 'vscode';
-import * as path from 'path';
-import { Disposable } from './util/dispose';
 import * as arrays from './util/arrays';
+import { Disposable } from './util/dispose';
 
 const resolveExtensionResource = (extension: vscode.Extension<any>, resourcePath: string): vscode.Uri => {
-	return vscode.Uri.file(path.join(extension.extensionPath, resourcePath));
+	return vscode.Uri.joinPath(extension.extensionUri, resourcePath);
 };
 
 const resolveExtensionResources = (extension: vscode.Extension<any>, resourcePaths: unknown): vscode.Uri[] => {
@@ -158,4 +157,4 @@ class VSCodeExtensionMarkdownContributionProvider extends Disposable implements
 
 export function getMarkdownExtensionContributions(context: vscode.ExtensionContext): MarkdownContributionProvider {
 	return new VSCodeExtensionMarkdownContributionProvider(context.extensionPath);
-}
\ No newline at end of file
+}