QoL

internal/platform/implementation/linux/avahi.cc

@@ -27,7 +27,14 @@ void Server::onResolveServiceReply(const int32_t& interface,
     const std::string& address, const uint16_t& port,
     const std::vector<std::vector<uint8_t>>& txt, const uint32_t& flags,
     const sdbus::Error* error) {
+  if (error != nullptr && error->isValid()) {
+    LOG(ERROR) << __func__ << ": ResolveService failed with error '"
+               << error->getName() << "' message '" << error->getMessage()
+               << "'";
+    return;
+  }
 
+  LOG(INFO) << "Resolved reply received";
   NsdServiceInfo info;
 
   info.SetServiceName(name);

internal/platform/implementation/linux/avahi.h

@@ -29,6 +29,16 @@
 namespace nearby {
 namespace linux {
 namespace avahi {
+namespace {
+api::WifiLanMedium::DiscoveredServiceCallback MakeNoopDiscoveredServiceCallback() {
+  api::WifiLanMedium::DiscoveredServiceCallback cb{};
+
+  cb.service_discovered_cb = [](NsdServiceInfo) {};
+  cb.service_lost_cb       = [](NsdServiceInfo) {};
+
+  return cb;
+}
+} // namespace
 class Server final
     : public sdbus::ProxyInterfaces<org::freedesktop::Avahi::Server2_proxy> {
  public:
@@ -40,8 +50,12 @@ class Server final
     registerProxy();
   }
   Server(sdbus::IConnection& system_bus)
-    : Server(system_bus, {}) {}
+    : Server(system_bus, MakeNoopDiscoveredServiceCallback()) {}
   ~Server() { unregisterProxy(); }
+  void SetDiscoveryCallback(
+      api::WifiLanMedium::DiscoveredServiceCallback callback) {
+    discovery_cb_ = std::move(callback);
+  }
   api::WifiLanMedium::DiscoveredServiceCallback discovery_cb_;
  protected:
   void onStateChanged(const int32_t &state, const std::string &error) override {
@@ -88,7 +102,6 @@ class ServiceBrowser final
  public:
   ServiceBrowser(sdbus::IConnection &system_bus,
                  const sdbus::ObjectPath &service_browser_object_path,
-                 api::WifiLanMedium::DiscoveredServiceCallback callback,
                  std::shared_ptr<Server> avahi_server)
       : ProxyInterfaces(system_bus, "org.freedesktop.Avahi",
                         service_browser_object_path),