test: add tests for malformed links

internal/pkg/crawl/link_header_test.go

@@ -37,17 +37,64 @@ func TestParseMultipleLinks(t *testing.T) {
 	}
 }
 
+func TestParseOneMalformedLink(t *testing.T) {
+	var links []Link
+	links = append(links, Link{URL: "https://one.example.com", Rel: "preconnect"})
+
+	var link = `https://one.example.com>;; rel=preconnect";`
+
+	got := Parse(link)
+	want := links
+
+	if !slices.Equal(got, want) {
+		t.Errorf("got %q, wanted %q", got, want)
+	}
+}
+
+func TestParseMultipleMalformedLinks(t *testing.T) {
+	var links []Link
+	links = append(links,
+		Link{URL: "", Rel: "preconnect"},
+		Link{URL: "https://app.test.com", Rel: ""},
+		Link{URL: "", Rel: ""},
+	)
+
+	var link = `; rel="preconnect", https://app.test.com; rel=""; "bar", <>; ="preconnect"`
+
+	got := Parse(link)
+	want := links
+
+	if !slices.Equal(got, want) {
+		t.Errorf("got %q, wanted %q", got, want)
+	}
+}
+
 func TestParseAttr(t *testing.T) {
 	attr := `rel="preconnect"`
 
 	gotKey, gotValue := ParseAttr(attr)
 	wantKey, wantValue := "rel", "preconnect"
 
-	if (gotKey != wantKey) {
+	if gotKey != wantKey {
+		t.Errorf("got %q, wanted %q", gotKey, wantKey)
+	}
+
+	if gotValue != wantValue {
+		t.Errorf("got %q, wanted %q", gotValue, wantValue)
+	}
+}
+
+func TestParseMalformedAttr(t *testing.T) {
+	attr := `="preconnect"`
+
+	gotKey, gotValue := ParseAttr(attr)
+	wantKey, wantValue := "", "preconnect"
+
+	if gotKey != wantKey {
 		t.Errorf("got %q, wanted %q", gotKey, wantKey)
 	}
 
-	if  (gotValue != wantValue) {
+	if gotValue != wantValue {
 		t.Errorf("got %q, wanted %q", gotValue, wantValue)
 	}
 }