Support latest md ls (#160228)

- Update `looksLikeMarkdownPath` to look at open documents and notebooks, not just the uri
- Register custom command  for document links

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

@@ -40,7 +40,6 @@ export async function startClient(factory: LanguageClientConstructor, workspace:
 				return looksLikeMarkdownPath(resource);
 			},
 		},
-
 	};
 
 	const client = factory('markdown', localize('markdownServer.name', 'Markdown Language Server'), clientOptions);
@@ -116,6 +115,10 @@ export async function startClient(factory: LanguageClientConstructor, workspace:
 		watchers.delete(params.id);
 	});
 
+	vscode.commands.registerCommand('vscodeMarkdownLanguageservice.open', (uri, args) => {
+		return vscode.commands.executeCommand('vscode.open', uri, args);
+	});
+
 	await client.start();
 
 	return client;

extensions/markdown-language-features/src/util/file.ts

@@ -5,6 +5,7 @@
 
 import * as vscode from 'vscode';
 import * as URI from 'vscode-uri';
+import { Schemes } from './schemes';
 
 export const markdownFileExtensions = Object.freeze<string[]>([
 	'md',
@@ -22,6 +23,22 @@ export function isMarkdownFile(document: vscode.TextDocument) {
 	return document.languageId === 'markdown';
 }
 
-export function looksLikeMarkdownPath(resolvedHrefPath: vscode.Uri) {
+export function looksLikeMarkdownPath(resolvedHrefPath: vscode.Uri): boolean {
+	const doc = vscode.workspace.textDocuments.find(doc => doc.uri.toString() === resolvedHrefPath.toString());
+	if (doc) {
+		return isMarkdownFile(doc);
+	}
+
+	if (resolvedHrefPath.scheme === Schemes.notebookCell) {
+		for (const notebook of vscode.workspace.notebookDocuments) {
+			for (const cell of notebook.getCells()) {
+				if (cell.kind === vscode.NotebookCellKind.Markup && isMarkdownFile(cell.document)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
 	return markdownFileExtensions.includes(URI.Utils.extname(resolvedHrefPath).toLowerCase().replace('.', ''));
 }