InstanceMethod does not accept function returning Napi::Object

[th3r0b0t]

Hello, First off, I send my sincere regards for all the time and efforts you put into the project.

Preface

I have a simple C++ class as below:

class mmapIPC : public Napi::ObjectWrap<mmapIPC>
{
  public:
    static Napi::Object Init(Napi::Env env, Napi::Object exports);
    mmapIPC(const Napi::CallbackInfo& info);
    static Napi::Value CreateNewItem(const Napi::CallbackInfo& info);

  private:
    //-----------members
    shm_metadata shm_hint;
    Napi::Buffer<void> memoryBuffer;
    //-----------funcs
    Napi::Object buffer(const Napi::CallbackInfo& info);
    Napi::Value acquireReadLock(const Napi::CallbackInfo& info);
    Napi::Value acquireWriteLock(const Napi::CallbackInfo& info);
    Napi::Value removeLock(const Napi::CallbackInfo& info);
    //-----------statics
    static void freeCallback(Napi::Env, void* memoryAddress, shm_metadata* hint);
    static int createShmFile( const char *name, std::size_t memLenght);
    static void* mapMemory( int shm_fd, std::size_t regionLength, bool lockPagesToRam );
};

Which is based on examples of this repo for object_wrap; Now in my static Napi::Object Init I have the following code to export members:

// This method is used to hook the accessor and method callbacks
    Napi::Function functionList = DefineClass(env, "mmapIPC",
    {
        InstanceMethod<&mmapIPC::buffer>("buffer", static_cast<napi_property_attributes>(napi_writable | napi_configurable)),
        InstanceMethod<&mmapIPC::acquireReadLock>("acquireReadLock", static_cast<napi_property_attributes>(napi_writable | napi_configurable)),
        InstanceMethod<&mmapIPC::acquireWriteLock>("acquireWriteLock", static_cast<napi_property_attributes>(napi_writable | napi_configurable)),
        InstanceMethod<&mmapIPC::removeLock>("removeLock", static_cast<napi_property_attributes>(napi_writable | napi_configurable)),
        StaticMethod<&mmapIPC::CreateNewItem>("CreateNewItem", static_cast<napi_property_attributes>(napi_writable | napi_configurable))
    });

And definition for Napi::Object buffer is (it's some kind of setter/getter accessor at the same?) :

Napi::Object mmapIPC::buffer(const Napi::CallbackInfo& info)
{
    return this->memoryBuffer;
}

Questions:

1. First of all, when I set the return type for buffer() function as Napi::Object the InstanceMethod complains about it, and when I change it to Napi::Value even tho it seems I can use buf1.buffer().write('Balh Blah', 'ascii') to write into the buffer, calling buf1.buffer().toString('ascii') prints the whole stack trace of node! I should note that when I tested the code without OOP, exporting buffer() with Napi::Object as return type was fine and everything was working smoothly:

exports.Set(Napi::String::New(env, "buffer"),
                Napi::Function::New(env, buffer));

2. In this code, is it fine to supply void as the type? If not, what else? char or u_int8_t perhaps?:

this->memoryBuffer =  Napi::Buffer<void>::New(
                        env,
                        externalData,
                        this->shm_hint.mmapLength,
                        freeCallback,
                        &this->shm_hint);

3. In the example for object_wrap there's this static Napi::Value CreateNewItem(const Napi::CallbackInfo& info) method which retrieves the stored constructor and I quote: "to create a new instance of the JS class the constructor represents". What does this method do? Couldn't I just create another instance using the required constructor in my JS code? It says in the comments for static Napi::Object Init(Napi::Env env, Napi::Object exports) that: "allow this add-on to support multiple instances of itself running on multiple worker threads, as well as multiple instances of itself running in different contexts on the same thread"! So is this method necessary?

---

P.S: I'm very truly sorry if this turned out to be a long question; I just wanted to ask it all once and get it over with...