From 434783165bbdd6adfd1084f6790d370634757d82 Mon Sep 17 00:00:00 2001
From: Jason Streifling <jason@streifling.com>
Date: Thu, 17 Oct 2024 05:18:02 +0200
Subject: [PATCH] Add needed checks for link if attributes are empty

---
 link.go | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/link.go b/link.go
index 3b83214..e369703 100644
--- a/link.go
+++ b/link.go
@@ -38,16 +38,22 @@ func (l *Link) Check() error {
 		}
 	}
 
-	if strings.Contains(l.Rel, ":") && !isValidIRI(IRI(l.Rel)) {
-		return fmt.Errorf("rel attribute %v of link %v not correctly formatted", l.Rel, l.Href)
+	if l.Rel != "" {
+		if strings.Contains(l.Rel, ":") && !isValidIRI(IRI(l.Rel)) {
+			return fmt.Errorf("rel attribute %v of link %v not correctly formatted", l.Rel, l.Href)
+		}
 	}
 
-	if !isValidMediaType(string(l.Type)) {
-		return fmt.Errorf("type attribute %v of link %v invalid media type", l.Type, l.Href)
+	if l.Type != "" {
+		if !isValidMediaType(string(l.Type)) {
+			return fmt.Errorf("type attribute %v of link %v invalid media type", l.Type, l.Href)
+		}
 	}
 
-	if !isValidLanguageTag(l.HrefLang) {
-		return fmt.Errorf("hreflang attribute %v of link %v invalid language tag", l.Type, l.HrefLang)
+	if l.HrefLang != "" {
+		if !isValidLanguageTag(l.HrefLang) {
+			return fmt.Errorf("hreflang attribute %v of link %v invalid language tag", l.Type, l.HrefLang)
+		}
 	}
 
 	if l.Content == nil {