nodejs
Do we need `wrapper_`?
In our ObjectWrap N-API examples we store the napi_ref returned from napi_wrap() in the native object instance although we never use it. To napi_delete_reference() in the destructor we need to also store the napi_env on the native instance – a practice we discourage.
Do we do this for illustration purposes? Can we remove this, since wrapper_ is not being used anywhere?
This is the extent to which we use wrapper_ and env_:
https://github.com/nodejs/node-addon-examples/blob/dc86a662c27c5732e069e1c19d3b7a8e74e86d29/6_object_wrap/napi/myobject.cc#L6-L11
and
https://github.com/nodejs/node-addon-examples/blob/dc86a662c27c5732e069e1c19d3b7a8e74e86d29/6_object_wrap/napi/myobject.cc#L72-L78
Compare with the Nan implementation. The use of the persistent reference may stem from there. If so, it may be a good time to diverge, especially since we document that we discourage storing the napi_env.
In fact, none of the Nan examples store a persistent reference to the JS instance. We should remove it.