[js] use textToMarkedString in JSON contributions

extensions/javascript/src/features/bowerJSONContribution.ts

@@ -8,6 +8,7 @@ import {MarkedString, CompletionItemKind, CompletionItem, DocumentSelector} from
 import {IJSONContribution, ISuggestionsCollector} from './jsonContributions';
 import {XHRRequest} from 'request-light';
 import {Location} from 'jsonc-parser';
+import {textToMarkedString} from './markedTextUtil';
 
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
@@ -173,7 +174,7 @@ export class BowerJSONContribution implements IJSONContribution {
 				htmlContent.push(localize('json.bower.package.hover', '{0}', pack));
 				return this.getInfo(pack).then(documentation => {
 					if (documentation) {
-						htmlContent.push({ language: 'string', value: documentation});
+						htmlContent.push(textToMarkedString(documentation));
 					}
 					return htmlContent;
 				});

extensions/javascript/src/features/markedTextUtil.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 {MarkedString} from 'vscode';
+
+export function textToMarkedString(text: string) : MarkedString {
+	return text.replace(/[\\`*_{}[\]()#+\-.!]/g, '\\$&'); // escape markdown syntax tokens: http://daringfireball.net/projects/markdown/syntax#backslash
+}
\ No newline at end of file

extensions/javascript/src/features/packageJSONContribution.ts

@@ -8,6 +8,7 @@ import {MarkedString, CompletionItemKind, CompletionItem, DocumentSelector} from
 import {IJSONContribution, ISuggestionsCollector} from './jsonContributions';
 import {XHRRequest} from 'request-light';
 import {Location} from 'jsonc-parser';
+import {textToMarkedString} from './markedTextUtil';
 
 import * as nls from 'vscode-nls';
 const localize = nls.loadMessageBundle();
@@ -214,7 +215,7 @@ export class PackageJSONContribution implements IJSONContribution {
 				htmlContent.push(localize('json.npm.package.hover', '{0}', pack));
 				return this.getInfo(pack).then(infos => {
 					infos.forEach(info => {
-						htmlContent.push({language: 'string', value: info});
+						htmlContent.push(textToMarkedString(info));
 					});
 					return htmlContent;
 				});