Make CleanupHook public

napi-inl.h

@@ -6233,6 +6233,11 @@ Env::CleanupHook<Hook> Env::AddCleanupHook(Hook hook) {
   return CleanupHook<Hook>(*this, hook);
 }
 
+template <typename Hook, typename Arg>
+Env::CleanupHook<Hook, Arg>::CleanupHook() {
+  data = nullptr;
+}
+
 template <typename Hook, typename Arg>
 Env::CleanupHook<Hook, Arg>::CleanupHook(Napi::Env env, Hook hook)
     : wrapper(Env::CleanupHook<Hook, Arg>::Wrapper) {

napi.h

@@ -283,10 +283,7 @@ using MaybeOrValue = T;
 /// corresponds to an Isolate.
 class Env {
  private:
-#if NAPI_VERSION > 2
-  template <typename Hook, typename Arg = void>
-  class CleanupHook;
-#endif  // NAPI_VERSION > 2
+  napi_env _env;
 #if NAPI_VERSION > 5
   template <typename T>
   static void DefaultFini(Env, T* data);
@@ -310,6 +307,9 @@ class Env {
   MaybeOrValue<Value> RunScript(String script) const;
 
 #if NAPI_VERSION > 2
+  template <typename Hook, typename Arg = void>
+  class CleanupHook;
+
   template <typename Hook>
   CleanupHook<Hook> AddCleanupHook(Hook hook);
 
@@ -335,13 +335,11 @@ class Env {
   void SetInstanceData(DataType* data, HintType* hint) const;
 #endif  // NAPI_VERSION > 5
 
- private:
-  napi_env _env;
-
 #if NAPI_VERSION > 2
   template <typename Hook, typename Arg>
   class CleanupHook {
    public:
+    CleanupHook();
     CleanupHook(Env env, Hook hook, Arg* arg);
     CleanupHook(Env env, Hook hook);
     bool Remove(Env env);
@@ -357,8 +355,8 @@ class Env {
       Arg* arg;
     } * data;
   };
-};
 #endif  // NAPI_VERSION > 2
+};
 
 /// A JavaScript value of unknown type.
 ///

test/env_cleanup.cc

@@ -20,6 +20,13 @@ static void cleanupVoid() {
 static int secret1 = 42;
 static int secret2 = 43;
 
+class TestClass {
+ public:
+  Env::CleanupHook<void (*)(void* arg), int> hook;
+
+  void removeHook(Env env) { hook.Remove(env); }
+};
+
 Value AddHooks(const CallbackInfo& info) {
   auto env = info.Env();
 
@@ -72,6 +79,11 @@ Value AddHooks(const CallbackInfo& info) {
   added += !hook5.IsEmpty();
   added += !hook6.IsEmpty();
 
+  // Test store a hook in a member class variable
+  auto myclass = TestClass();
+  myclass.hook = env.AddCleanupHook(cleanup, &secret1);
+  myclass.removeHook(env);
+
   return Number::New(env, added);
 }