feat: redirect browse to canonical sfw url

internal/anime/browse_handler_test.go

@@ -0,0 +1,39 @@
+package anime
+
+import (
+	"net/url"
+	"testing"
+)
+
+func TestCanonicalBrowseURLAddsSFWTrueWhenMissing(t *testing.T) {
+	t.Parallel()
+
+	rawURL, err := url.Parse("/browse?status=airing&order_by=popularity&sort=asc")
+	if err != nil {
+		t.Fatalf("url.Parse() error = %v", err)
+	}
+
+	got, ok := canonicalBrowseURL(rawURL)
+	if !ok {
+		t.Fatal("canonicalBrowseURL() should request redirect when sfw is missing")
+	}
+
+	want := "/browse?order_by=popularity&sfw=true&sort=asc&status=airing"
+	if got != want {
+		t.Fatalf("canonicalBrowseURL() = %q, want %q", got, want)
+	}
+}
+
+func TestCanonicalBrowseURLSkipsWhenSFWAlreadyPresent(t *testing.T) {
+	t.Parallel()
+
+	rawURL, err := url.Parse("/browse?status=airing&sfw=false")
+	if err != nil {
+		t.Fatalf("url.Parse() error = %v", err)
+	}
+
+	got, ok := canonicalBrowseURL(rawURL)
+	if ok {
+		t.Fatalf("canonicalBrowseURL() unexpectedly requested redirect to %q", got)
+	}
+}