merged with fixes

internal/transport/metadata_test.go

@@ -0,0 +1,27 @@
+package transport
+
+import (
+	"context"
+	"testing"
+)
+
+func TestWithClientIPRoundTrip(t *testing.T) {
+	ctx := WithClientIP(context.Background(), "203.0.113.7")
+	ip, ok := ClientIPFrom(ctx)
+	if !ok || ip != "203.0.113.7" {
+		t.Fatalf("round-trip mismatch: got %q ok=%v", ip, ok)
+	}
+}
+
+func TestWithClientIPEmptyIgnored(t *testing.T) {
+	ctx := WithClientIP(context.Background(), "")
+	if _, ok := ClientIPFrom(ctx); ok {
+		t.Fatalf("empty ip must not be stored")
+	}
+}
+
+func TestClientIPFromNotSet(t *testing.T) {
+	if _, ok := ClientIPFrom(context.Background()); ok {
+		t.Fatalf("no ip set, ok must be false")
+	}
+}