Add anti-buffering relay headers and optional randomized query suffixes

internal/client/http_headers_test.go

@@ -0,0 +1,53 @@
+package client
+
+import (
+	"net/url"
+	"strings"
+	"testing"
+
+	"masterhttprelayvpn/internal/config"
+)
+
+func TestBuildRelayURLLeavesURLUntouchedWhenSuffixRandomizationDisabled(t *testing.T) {
+	builder := newRelayHeaderBuilder(config.Config{
+		RelayURL:                 "https://example.com/relay",
+		HTTPRandomizeQuerySuffix: false,
+	}, nil)
+
+	got := builder.BuildRelayURL("https://example.com/relay")
+	if got != "https://example.com/relay" {
+		t.Fatalf("expected relay URL to stay unchanged, got %q", got)
+	}
+}
+
+func TestBuildRelayURLAddsRandomQuerySuffixWhenEnabled(t *testing.T) {
+	builder := newRelayHeaderBuilder(config.Config{
+		RelayURL:                 "https://example.com/relay?existing=1",
+		HTTPRandomizeQuerySuffix: true,
+	}, nil)
+
+	got := builder.BuildRelayURL("https://example.com/relay?existing=1")
+	parsed, err := url.Parse(got)
+	if err != nil {
+		t.Fatalf("parse randomized relay URL: %v", err)
+	}
+
+	query := parsed.Query()
+	if query.Get("existing") != "1" {
+		t.Fatalf("expected existing query parameter to be preserved, got %q", query.Get("existing"))
+	}
+
+	randomKeys := []string{"webhe", "r", "_", "cache_bust", "v"}
+	found := false
+	for _, key := range randomKeys {
+		if value := query.Get(key); value != "" {
+			found = true
+			if strings.TrimSpace(value) == "" {
+				t.Fatalf("expected randomized query value for key %q to be non-empty", key)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected one randomized query suffix key, got query %q", parsed.RawQuery)
+	}
+}