n-api: ensure scope present for finalization

Refs: nodejs/node-addon-api#722

Ensure a scope is on stack during finalization
as finalization functions can create JS Objects

Signed-off-by: Michael Dawson <michael_dawson@ca.ibm.com>

src/js_native_api_v8.cc

@@ -267,6 +267,7 @@ class RefBase : protected Finalizer, RefTracker {
  protected:
   inline void Finalize(bool is_env_teardown = false) override {
     if (_finalize_callback != nullptr) {
+      v8::HandleScope handle_scope(_env->isolate);
       _env->CallIntoModule([&](napi_env env) {
         _finalize_callback(
             env,

test/node-api/test_worker_terminate_finalization/binding.gyp

@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "test_worker_terminate_finalization",
+      "sources": [ "test_worker_terminate_finalization.c" ]
+    }
+  ]
+}

test/node-api/test_worker_terminate_finalization/test.js

@@ -0,0 +1,18 @@
+'use strict';
+const common = require('../../common');
+const { Worker, isMainThread } = require('worker_threads');
+
+if (isMainThread) {
+  const worker = new Worker(__filename);
+  worker.on('error', common.mustNotCall());
+} else {
+  const { Test } =
+    require(`./build/${common.buildType}/test_worker_terminate_finalization`);
+
+  // Spin up thread and call add-on create the right sequence
+  // of rerences to hit the case reported in
+  // https://github.com/nodejs/node-addon-api/issues/722
+  // will crash if run under debug and its not possible to
+  // create object in the specific finalizer
+  Test(new Object());
+}

test/node-api/test_worker_terminate_finalization/test_worker_terminate_finalization.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <node_api.h>
+#include <assert.h>
+#include <malloc.h>
+#include "../../js-native-api/common.h"
+
+int wrappedNativeData;
+napi_ref ref;
+void WrapFinalizer(napi_env env, void* data, void* hint) {
+  uint32_t count;
+  NAPI_CALL_RETURN_VOID(env, napi_reference_unref(env, ref, &count));
+}
+
+napi_value Test(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value argv[1];
+  napi_value result;
+  napi_ref ref;
+  napi_ref wrapResult;
+
+  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, argv, NULL, NULL));
+  NAPI_CALL(env, napi_create_external_buffer(env, 4, (void*) malloc(4), NULL, NULL, &result));
+  NAPI_CALL(env, napi_create_reference(env, result, 1, &ref));
+  NAPI_CALL(env, napi_wrap(env, argv[0], (void*) &wrappedNativeData, WrapFinalizer, NULL, &wrapResult));
+  return NULL;
+}
+
+napi_value Init(napi_env env, napi_value exports) {
+  napi_property_descriptor properties[] = {
+    DECLARE_NAPI_PROPERTY("Test", Test)
+  };
+
+  NAPI_CALL(env, napi_define_properties(
+      env, exports, sizeof(properties) / sizeof(*properties), properties));
+
+  return exports;
+}
+
+// Do not start using NAPI_MODULE_INIT() here, so that we can test
+// compatibility of Workers with NAPI_MODULE().
+NAPI_MODULE(NODE_GYP_MODULE_NAME, Init)