Error using ObjectReference to ObjectWrap in node console

[trxcllnt]

I have a native module that's throwing an error, but only when running in the node console, not in a script. This makes me think I have a C++ instance lifetime issue, but I can't see anything obvious, and similar code in other places is behaving fine.

I've boiled the issue down to this small example. A C++ ObjectWrap instantiates and holds a reference to another ObjectWrap instance. Later, the outer ObjectWrap instance delegates various behavior to the inner instance.

Here's the example in JS:

class Child { get value() { return 5; } }
class Parent {
  constructor() { this.child = new Child(); }
  get value() { return this.child.value; }
}
let p =  new Parent();
p.value // 5

Below is my attempt to replicate the above in C++, but I'm seeing this error in the node console. It looks like there's an initial error being thrown, but then another error constructing the Napi::Error, leading to the abort:

$ node
Welcome to Node.js v15.4.0.
Type ".help" for more information.
> const { Parent } = require('./build/addon.node');
undefined
> const p = new Parent()
undefined
> p.child.value
5
> p.valueFATAL ERROR: Error::Error napi_create_reference
 1: 0xa68ab0 node::Abort() [node]
 2: 0x99bc57 node::FatalError(char const*, char const*) [node]
 3: 0x99bc60  [node]
 4: 0xa3933b napi_fatal_error [node]
 5: 0x7f6165498d44 Napi::Error::Error(napi_env__*, napi_value__*) [./build/addon.node]
 6: 0x7f6165498dea Napi::Error::Error(napi_env__*, napi_value__*) [./build/addon.node]
 7: 0x7f6165498c75 Napi::Error::New(napi_env__*) [./build/addon.node]
 8: 0x7f616549832f Napi::Object::Get(char const*) const [./build/addon.node]
 9: 0x7f616549933a Napi::ObjectReference::Get(char const*) const [./build/addon.node]
10: 0x7f616549b7b1 Parent::get_value(Napi::CallbackInfo const&) [./build/addon.node]
11: 0x7f616548fd6f  [./build/addon.node]
12: 0x7f616548ffb5  [./build/addon.node]
13: 0x7f616548fe07  [./build/addon.node]
14: 0xa1c5bf  [node]
15: 0x1469a4d  [node]
Aborted

But if I run it in a script, I don't get any errors:

// test.js
const { Parent } = require('./build/addon.node');
const p = new Parent();
console.log('p.value:', p.value);
console.log('p.child.value:', p.child.value);
// Give the GC time to sweep before accessing again
setTimeout(() => console.log('p.value:', p.value), 1000);
/*
$ node test.js
p.value: 5
p.child.value: 5
p.value: 5
*/

The C++:

#include <napi.h>

struct Child : public Napi::ObjectWrap<Child> {
  static Napi::FunctionReference constructor;
  static auto Init(Napi::Env env, Napi::Object exports) {
    exports.Set("Child", [&]() {
      (Child::constructor = Napi::Persistent(DefineClass(
         env, "Child", {InstanceAccessor<&Child::get_value>("value", napi_enumerable)})))
        .SuppressDestruct();
      return Child::constructor.Value();
    }());
    return exports;
  }
  Child(Napi::CallbackInfo const& info) : Napi::ObjectWrap<Child>(info){};
  Napi::Value get_value(Napi::CallbackInfo const& info) { return Napi::Number::New(info.Env(), 5); }
};

Napi::FunctionReference Child::constructor;

struct Parent : public Napi::ObjectWrap<Parent> {
  static Napi::FunctionReference constructor;
  static auto Init(Napi::Env env, Napi::Object exports) {
    exports.Set("Parent", [&]() {
      (Parent::constructor = Napi::Persistent(
         DefineClass(env,
                     "Parent",
                     {InstanceAccessor<&Parent::get_child>("child", napi_enumerable),
                      InstanceAccessor<&Parent::get_value>("value", napi_enumerable)})))
        .SuppressDestruct();
      return Parent::constructor.Value();
    }());
    return exports;
  }
  Parent(Napi::CallbackInfo const& info)
    : Napi::ObjectWrap<Parent>(info),  //
      child(Napi::Persistent(Child::constructor.New({}))){};
  Napi::Value get_child(Napi::CallbackInfo const& info) { return child.Value(); }
  Napi::Value get_value(Napi::CallbackInfo const& info) {
    // These blow up in the node console:
    // child.Value().InstanceOf(Child::constructor.Value());
    // return child.Value().Get("value");
    return child.Get("value");
    // This doesn't blow up in the node console:
    // return Child::Unwrap(child.Value())->get_value(info);
  }
  Napi::ObjectReference child;
};

Napi::FunctionReference Parent::constructor;

Napi::Object init(Napi::Env env, Napi::Object exports) {
  Child::Init(env, exports);
  Parent::Init(env, exports);
  return exports;
}

NODE_API_MODULE(addon, init);

Any ideas what could be going wrong here?

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