From 3143f62f6185cf2fee9f20178d2c6c063184d426 Mon Sep 17 00:00:00 2001
From: Ben McCann <322311+benmccann@users.noreply.github.com>
Date: Sat, 28 Jan 2023 05:57:28 -0800
Subject: [PATCH] add comment

---
 src/compiler/compile/nodes/Element.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 6218032ee0..4289e948f2 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -621,7 +621,10 @@ export default class Element extends Node {
 			const name_attribute = attribute_map.get('name');
 			const target_attribute = attribute_map.get('target');
 
-			if (component.compile_options.legacy && target_attribute && target_attribute.get_static_value() === '_blank' && href_attribute) {
+			// links with target="_blank" should have no opener or noreferrer: https://developer.chrome.com/docs/lighthouse/best-practices/external-anchors-use-rel-noopener/
+			// modern browsers add noopener by default, so we only need to check legacy browsers
+			// legacy browsers don't support noopener so we only check for noreferrer there
+			If (component.compile_options.legacy && target_attribute && target_attribute.get_static_value() === '_blank' && href_attribute) {
 				const href_static_value = href_attribute.get_static_value() ? href_attribute.get_static_value().toLowerCase() : null;
 
 				if (href_static_value === null || href_static_value.match(/^(https?:)?\/\//i)) {