[smart_holder] Add missing test case to CMakeLists.txt (#3645)

* Add missing test case to CMakeLists.txt

* Fix warnings

* Fix Clangtidy

Author: wangxf123456

tests/CMakeLists.txt

@@ -136,6 +136,7 @@ set(PYBIND11_TEST_FILES
     test_class_sh_trampoline_unique_ptr
     test_class_sh_unique_ptr_member
     test_class_sh_virtual_py_cpp_mix
+    test_class_sh_void_ptr_capsule
     test_classh_mock
     test_const_name
     test_constants_and_functions

tests/test_class_sh_void_ptr_capsule.cpp

@@ -20,6 +20,7 @@ namespace class_sh_void_ptr_capsule {
 // Conveniently, the helper also serves to keep track of `capsule_generated`.
 struct HelperBase {
     HelperBase() = default;
+    HelperBase(const HelperBase &) = delete;
     virtual ~HelperBase() = default;
 
     bool capsule_generated = false;
@@ -45,7 +46,7 @@ struct NoConversion: public HelperBase {
 };
 
 struct NoCapsuleReturned: public HelperBase {
-    int get() const { return 103; }
+    int get() const override { return 103; }
 
     PyObject* as_pybind11_tests_class_sh_void_ptr_capsule_NoCapsuleReturned() {
       capsule_generated = true;
@@ -72,7 +73,7 @@ int get_from_valid_capsule(const Valid* c) {
   return c->get();
 }
 
-int get_from_shared_ptr_valid_capsule(std::shared_ptr<Valid> c) {
+int get_from_shared_ptr_valid_capsule(const std::shared_ptr<Valid> &c) {
   return c->get();
 }
 
@@ -109,7 +110,7 @@ TEST_SUBMODULE(class_sh_void_ptr_capsule, m) {
         .def(py::init<>())
         .def("as_pybind11_tests_class_sh_void_ptr_capsule_Valid",
              [](HelperBase* self) {
-          Valid *obj = dynamic_cast<Valid *>(self);
+          auto obj = dynamic_cast<Valid *>(self);
           assert(obj != nullptr);
           PyObject* capsule = obj->as_pybind11_tests_class_sh_void_ptr_capsule_Valid();
           return pybind11::reinterpret_steal<py::capsule>(capsule);
@@ -122,7 +123,7 @@ TEST_SUBMODULE(class_sh_void_ptr_capsule, m) {
         .def(py::init<>())
         .def("as_pybind11_tests_class_sh_void_ptr_capsule_NoCapsuleReturned",
              [](HelperBase* self) {
-          NoCapsuleReturned *obj = dynamic_cast<NoCapsuleReturned *>(self);
+          auto obj = dynamic_cast<NoCapsuleReturned *>(self);
           assert(obj != nullptr);
           PyObject* capsule = obj->as_pybind11_tests_class_sh_void_ptr_capsule_NoCapsuleReturned();
           return pybind11::reinterpret_steal<py::capsule>(capsule);
@@ -132,7 +133,7 @@ TEST_SUBMODULE(class_sh_void_ptr_capsule, m) {
         .def(py::init<>())
         .def("as_pybind11_tests_class_sh_void_ptr_capsule_Valid",
              [](HelperBase* self) {
-          AsAnotherObject *obj = dynamic_cast<AsAnotherObject *>(self);
+          auto obj = dynamic_cast<AsAnotherObject *>(self);
           assert(obj != nullptr);
           PyObject* capsule = obj->as_pybind11_tests_class_sh_void_ptr_capsule_Valid();
           return pybind11::reinterpret_steal<py::capsule>(capsule);