[BUG] node REPL crashes creating ObjectWrap in getter

[trxcllnt]

The node REPL seems to crash if a C++ getter creates an instance of a class that extends ObjectWrap.

This works in a script, but it crashes as soon as the REPL's auto-complete attempts to "preview" bar.get_new_foo:

#include <napi.h>

struct Foo : public Napi::ObjectWrap<Foo> {
  static Napi::Function Init(Napi::Env env, Napi::Object exports) {
    return DefineClass(env, "Foo", {});
  }
  Foo(Napi::CallbackInfo const& info) : Napi::ObjectWrap<Foo>(info){};
};

struct Bar : public Napi::ObjectWrap<Bar> {
  static Napi::Function Init(Napi::Env env, Napi::Object exports) {
    FooConstructor = Napi::Persistent(Foo::Init(env, exports));
    FooConstructor.SuppressDestruct();
    return DefineClass(env, "Bar", {InstanceAccessor<&Bar::get_new_foo>("get_new_foo")});
  }

  Bar(Napi::CallbackInfo const& info) : Napi::ObjectWrap<Bar>(info){};

 private:
  static Napi::FunctionReference FooConstructor;
  Napi::Value get_new_foo(Napi::CallbackInfo const& info) {
    return FooConstructor.New({});
  }
};

Napi::FunctionReference Bar::FooConstructor;

struct NodeREPLCrashRepro : public Napi::Addon<NodeREPLCrashRepro> {
  NodeREPLCrashRepro(Napi::Env env, Napi::Object exports) {
    DefineAddon(exports, {InstanceValue("Bar", Bar::Init(env, exports))});
  }
};

NODE_API_ADDON(NodeREPLCrashRepro);

$ node
Welcome to Node.js v15.14.0.
Type ".help" for more information.
> var { Bar } = require(`./build/Debug/crash_repro.node`)
undefined
> var bar = new Bar()
undefined
> bar.gFATAL ERROR: Error::Error napi_create_reference
 1: 0xa89e60 node::Abort() [node]
 2: 0x9ade29 node::FatalError(char const*, char const*) [node]
 3: 0x9ade32  [node]
 4: 0xa55b3b napi_fatal_error [node]
 5: 0x7f3bf031ea4e Napi::ObjectReference::~ObjectReference() [build/Debug/crash_repro.node]
 6: 0x7f3bf031eb14 Napi::Error::Error(napi_env__*, napi_value__*) [build/Debug/crash_repro.node]
 7: 0x7f3bf031e97f Napi::Error::New(napi_env__*) [build/Debug/crash_repro.node]
 8: 0x7f3bf031e758 Napi::Function::New(unsigned long, napi_value__* const*) const [build/Debug/crash_repro.node]
 9: 0x7f3bf031e6d9 Napi::Function::New(std::initializer_list<napi_value__*> const&) const [build/Debug/crash_repro.node]
10: 0x7f3bf031f3a8 Napi::FunctionReference::New(std::initializer_list<napi_value__*> const&) const [build/Debug/crash_repro.node]
11: 0x7f3bf032050d Bar::get_new_foo(Napi::CallbackInfo const&) [build/Debug/crash_repro.node]
12: 0x7f3bf031db65  [build/Debug/crash_repro.node]
13: 0x7f3bf031dc39  [build/Debug/crash_repro.node]
14: 0x7f3bf031dbfd  [build/Debug/crash_repro.node]
15: 0xa390bf  [node]
16: 0x149e62d  [node]
Aborted

[trxcllnt]

There seem to be two issues here:

1. The napi_new_instance() call here returns a napi_generic_failure status.
2. NAPI_THROW_IF_FAILED calls this Error constructor.
   a. That constructor passes the env/error pair to this Error constructor.
   b. That constructor's napi_create_reference call returns an error code.

This is reminiscent of Python's "while handling the original error, another error occurred" message.

[legendecas]

There are several problems in the case:

1. napi_new_instance returned napi_generic_failure instead of napi_pending_exception on JavaScript exceptions (v8 throws on calling functions with side effects when previewing).
2. The value v8 thrown is a plain string, which would cause Napi::Env::GetAndClearPendingException assumes exceptions are Error objects #912 to abort.

Please let me know if there are any other conditions that may apply. I'll submit patches shortly.

[bl-ue]

Should this be closed now that nodejs/node#38798 is landed?

[mhdawson]

@trxcllnt could you verify if the fix landed has addressed your issue?

[trxcllnt]

@mhdawson is there a build of v16.4.0 I can try? I'm not set up to build node at the moment.

[mhdawson]

@trxcllnt these are the nightly builds for master: https://nodejs.org/download/nightly/v17.0.0-nightly20210616767996047c/

I think that would like be the best place to test as 16.4 is not out yet. I do see it in the release proposal though: nodejs/node#39031 and the target for v16.4.0 shows as 15 June (nodejs/Release#658) so it may be coming soon.

[danielleadams]

@trxcllnt @mhdawson I am hoping to get 16.4 out tomorrow after the next npm release goes out.

[mhdawson]

@danielleadams thanks for the update :)

[trxcllnt]

Not resolved in node v16.4.0:

$ node
Welcome to Node.js v16.4.0.
Type ".help" for more information.
> var b = new (require('./build/Debug/crash_repro.node')).Bar()
undefined
> b.gFATAL ERROR: Error::Error napi_create_reference
 1: 0xb200e0 node::Abort() [node]
 2: 0xa3c157 node::FatalError(char const*, char const*) [node]
 3: 0xa3c160  [node]
 4: 0xaeb7ab napi_fatal_error [node]
 5: 0x7f19189d0a4e Napi::ObjectReference::~ObjectReference() [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
 6: 0x7f19189d0b14 Napi::Error::Error(napi_env__*, napi_value__*) [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
 7: 0x7f19189d097f Napi::Error::New(napi_env__*) [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
 8: 0x7f19189d0758 Napi::Function::New(unsigned long, napi_value__* const*) const [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
 9: 0x7f19189d06d9 Napi::Function::New(std::initializer_list<napi_value__*> const&) const [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
10: 0x7f19189d13a8 Napi::FunctionReference::New(std::initializer_list<napi_value__*> const&) const [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
11: 0x7f19189d250d Bar::get_new_foo(Napi::CallbackInfo const&) [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
12: 0x7f19189cfb65  [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
13: 0x7f19189cfc39  [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
14: 0x7f19189cfbfd  [/home/ptaylor/dev/node-addon-cmake-js-sandbox/build/Debug/crash_repro.node]
15: 0xaceebf  [node]
16: 0x15dbdcc  [node]
Aborted

[mhdawson]

@trxcllnt thanks for the update. Seems like we've only fixed one of the several issues that @legendecas mentioned. I think we discussed options that are related to this issue in the Node-api team meeting today.

[github-actions]

This issue is stale because it has been open many days with no activity. It will be closed soon unless the stale label is removed or a comment is made.