modules/hyprland/backend: handle empty json responses

Fixes https://github.com/Alexays/Waybar/issues/3388

src/modules/hyprland/backend.cpp

@@ -218,7 +218,13 @@ std::string IPC::getSocket1Reply(const std::string& rq) {
 }
 
 Json::Value IPC::getSocket1JsonReply(const std::string& rq) {
-  return parser_.parse(getSocket1Reply("j/" + rq));
+  std::string reply = getSocket1Reply("j/" + rq);
+
+  if (reply.empty()) {
+    return {};
+  }
+
+  return parser_.parse(reply);
 }
 
 }  // namespace waybar::modules::hyprland

test/hyprland/backend.cpp

@@ -1,4 +1,3 @@
-#include <cstdlib>
 #if __has_include(<catch2/catch_test_macros.hpp>)
 #include <catch2/catch_test_macros.hpp>
 #else
@@ -6,7 +5,6 @@
 #endif
 
 #include "fixtures/IPCTestFixture.hpp"
-#include "modules/hyprland/backend.hpp"
 
 namespace fs = std::filesystem;
 namespace hyprland = waybar::modules::hyprland;
@@ -53,3 +51,11 @@ TEST_CASE_METHOD(IPCTestFixture, "XDGRuntimeDirExistsNoHyprDir", "[getSocketFold
   // Assert expected result
   REQUIRE(actualPath == expectedPath);
 }
+
+TEST_CASE_METHOD(IPCMock, "getSocket1JsonReply handles empty response", "[getSocket1JsonReply]") {
+  std::string request = "test_request";
+
+  Json::Value jsonResponse = getSocket1JsonReply(request);
+
+  REQUIRE(jsonResponse.isNull());
+}

test/hyprland/fixtures/IPCTestFixture.hpp

@@ -14,3 +14,9 @@ class IPCTestFixture : public hyprland::IPC {
 
  private:
 };
+
+class IPCMock : public IPCTestFixture {
+ public:
+  // Mock getSocket1Reply to return an empty string
+  static std::string getSocket1Reply(const std::string& rq) { return ""; }
+};