Fix parameter not being escaped

Fixes #49057

extensions/typescript-language-features/src/features/jsDocCompletionProvider.ts

@@ -206,6 +206,7 @@ class TryCompleteJsDocCommand implements Command {
 export function templateToSnippet(template: string): SnippetString {
 	// TODO: use append placeholder
 	let snippetIndex = 1;
+	template = template.replace(/\$/g, '\\$');
 	template = template.replace(/^\s*(?=(\/|[ ]\*))/gm, '');
 	template = template.replace(/^(\/\*\*\s*\*[ ]*)$/m, (x) => x + `\$0`);
 	template = template.replace(/\* @param([ ]\{\S+\})?\s+(\S+)\s*$/gm, (_param, type, post) => {

extensions/typescript-language-features/src/test/jsdocSnippet.test.ts

@@ -70,7 +70,7 @@ suite('typescript.jsDocSnippet', () => {
 			[
 				'/**',
 				' * $0',
-				' * @param $arg ${1}',
+				' * @param \\$arg ${1}',
 				' */'
 			].join('\n'));
 	});