Add MockedEmptyHandlersServer fuzz target

fuzzing/Makefile

@@ -16,6 +16,7 @@ oss-fuzz:
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 -DLIBUS_NO_SSL -I../src -I../uSockets/src MockedHelloWorld.cpp uSocketsMock.o -lz -o $(OUT)/MockedHelloWorld $(LIB_FUZZING_ENGINE)
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 -DLIBUS_NO_SSL -I../src -I../uSockets/src MockedEchoServer.cpp uSocketsMock.o -lz -o $(OUT)/MockedEchoServer $(LIB_FUZZING_ENGINE)
 	$(CXX) $(CXXFLAGS) -std=c++17 -O3 -DLIBUS_NO_SSL -I../src -I../uSockets/src MockedBroadcastingEchoServer.cpp uSocketsMock.o -lz -o $(OUT)/MockedBroadcastingEchoServer $(LIB_FUZZING_ENGINE)
+	$(CXX) $(CXXFLAGS) -std=c++17 -O3 -DLIBUS_NO_SSL -I../src -I../uSockets/src MockedEmptyHandlersServer.cpp uSocketsMock.o -lz -o $(OUT)/MockedEmptyHandlersServer $(LIB_FUZZING_ENGINE)
 
 broken:
 # Too small tests, failing coverage test

fuzzing/MockedEmptyHandlersServer.cpp

@@ -0,0 +1,36 @@
+#include "App.h"
+
+#include "helpers.h"
+
+/* This function pushes data to the uSockets mock */
+extern "C" void us_loop_read_mocked_data(struct us_loop *loop, char *data, unsigned int size);
+
+uWS::TemplatedApp<false> *app;
+us_listen_socket_t *listenSocket;
+
+extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv) {
+
+    app = new uWS::App();
+
+    struct PerSocketData {
+        int nothing;
+    };
+
+    app->ws<PerSocketData>("/*", {
+        /* Having no handlers here should not crash */
+    }).listen(9001, [](us_listen_socket_t *listenSocket) {
+        if (listenSocket) {
+            std::cout << "Listening on port " << 9001 << std::endl;
+            ::listenSocket = listenSocket;
+        }
+    });
+
+    return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+
+    us_loop_read_mocked_data((struct us_loop *) uWS::Loop::get(), (char *) makePadded(data, size), size);
+
+    return 0;
+}