Merge from vscode merge-base (#22780)

* Revert "Revert "Merge from vscode merge-base (#22769)" (#22779)"

This reverts commit 47a1745180.

* Fix notebook download task

* Remove done call from extensions-ci

extensions/markdown-language-features/server/src/languageFeatures/diagnostics.ts

@@ -0,0 +1,95 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Connection, FullDocumentDiagnosticReport, UnchangedDocumentDiagnosticReport } from 'vscode-languageserver';
+import * as md from 'vscode-markdown-languageservice';
+import { disposeAll } from 'vscode-markdown-languageservice/out/util/dispose';
+import { Disposable } from 'vscode-notebook-renderer/events';
+import { URI } from 'vscode-uri';
+import { ConfigurationManager, ValidateEnabled } from '../configuration';
+import { VsCodeClientWorkspace } from '../workspace';
+
+const defaultDiagnosticOptions: md.DiagnosticOptions = {
+	validateFileLinks: md.DiagnosticLevel.ignore,
+	validateReferences: md.DiagnosticLevel.ignore,
+	validateFragmentLinks: md.DiagnosticLevel.ignore,
+	validateMarkdownFileLinkFragments: md.DiagnosticLevel.ignore,
+	ignoreLinks: [],
+};
+
+function convertDiagnosticLevel(enabled: ValidateEnabled): md.DiagnosticLevel | undefined {
+	switch (enabled) {
+		case 'error': return md.DiagnosticLevel.error;
+		case 'warning': return md.DiagnosticLevel.warning;
+		case 'ignore': return md.DiagnosticLevel.ignore;
+		default: return md.DiagnosticLevel.ignore;
+	}
+}
+
+function getDiagnosticsOptions(config: ConfigurationManager): md.DiagnosticOptions {
+	const settings = config.getSettings();
+	if (!settings) {
+		return defaultDiagnosticOptions;
+	}
+
+	return {
+		validateFileLinks: convertDiagnosticLevel(settings.markdown.experimental.validate.fileLinks.enabled),
+		validateReferences: convertDiagnosticLevel(settings.markdown.experimental.validate.referenceLinks.enabled),
+		validateFragmentLinks: convertDiagnosticLevel(settings.markdown.experimental.validate.fragmentLinks.enabled),
+		validateMarkdownFileLinkFragments: convertDiagnosticLevel(settings.markdown.experimental.validate.fileLinks.markdownFragmentLinks),
+		ignoreLinks: settings.markdown.experimental.validate.ignoreLinks,
+	};
+}
+
+export function registerValidateSupport(
+	connection: Connection,
+	workspace: VsCodeClientWorkspace,
+	ls: md.IMdLanguageService,
+	config: ConfigurationManager,
+): Disposable {
+	let diagnosticOptions: md.DiagnosticOptions = defaultDiagnosticOptions;
+	function updateDiagnosticsSetting(): void {
+		diagnosticOptions = getDiagnosticsOptions(config);
+	}
+
+
+	const subs: Disposable[] = [];
+	const manager = ls.createPullDiagnosticsManager();
+	subs.push(manager);
+
+	subs.push(manager.onLinkedToFileChanged(() => {
+		// TODO: We only need to refresh certain files
+		connection.languages.diagnostics.refresh();
+	}));
+
+	connection.languages.diagnostics.on(async (params, token): Promise<FullDocumentDiagnosticReport | UnchangedDocumentDiagnosticReport> => {
+		if (!config.getSettings()?.markdown.experimental.validate.enabled) {
+			return { kind: 'full', items: [] };
+		}
+
+		const document = await workspace.openMarkdownDocument(URI.parse(params.textDocument.uri));
+		if (!document) {
+			return { kind: 'full', items: [] };
+		}
+
+		const diagnostics = await manager.computeDiagnostics(document, diagnosticOptions, token);
+		return {
+			kind: 'full',
+			items: diagnostics,
+		};
+	});
+
+	updateDiagnosticsSetting();
+	subs.push(config.onDidChangeConfiguration(() => {
+		updateDiagnosticsSetting();
+		connection.languages.diagnostics.refresh();
+	}));
+
+	return {
+		dispose: () => {
+			disposeAll(subs);
+		}
+	};
+}