Update test/helpers.ts

Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>

Author: dummdidumm

test/helpers.ts

@@ -145,7 +145,7 @@ export function normalizeHtml(window, html, { removeDataSvelte = false, preserve
 		const node = window.document.createElement('div');
 		node.innerHTML = html
 			.replace(/(<!--.*?-->)/g, preserveComments ? '$1' : '')
-			.replace(/(data-svelte="[^"]+")/g, removeDataSvelte ? '': '$1')
+			.replace(/(data-svelte="[^"]+")/g, removeDataSvelte ? '' : '$1')
 			.replace(/>[\s\r\n]+</g, '><')
 			.trim();
 		cleanChildren(node);