test: Add tests for cb scope

test/callbackscope.cc

@@ -1,8 +1,9 @@
+#include "assert.h"
 #include "napi.h"
-
 using namespace Napi;
 
 #if (NAPI_VERSION > 2)
+
 namespace {
 
 static void RunInCallbackScope(const CallbackInfo& info) {
@@ -12,11 +13,27 @@ static void RunInCallbackScope(const CallbackInfo& info) {
   callback.Call({});
 }
 
-}  // end anonymous namespace
+static void RunInCallbackScopeFromExisting(const CallbackInfo& info) {
+  Function callback = info[0].As<Function>();
+  Env env = info.Env();
+
+  AsyncContext ctx(env, "existing_callback_scope_test");
+  napi_callback_scope scope;
+  napi_open_callback_scope(env, Object::New(env), ctx, &scope);
+
+  CallbackScope existingScope(env, scope);
+  assert(existingScope.Env() == env);
+
+  callback.Call({});
+}
+
+}  // namespace
 
 Object InitCallbackScope(Env env) {
   Object exports = Object::New(env);
   exports["runInCallbackScope"] = Function::New(env, RunInCallbackScope);
+  exports["runInPreExistingCbScope"] =
+      Function::New(env, RunInCallbackScopeFromExisting);
   return exports;
 }
 #endif

test/callbackscope.js

@@ -24,7 +24,7 @@ function test (binding) {
   let insideHook = false;
   const hook = asyncHooks.createHook({
     init (asyncId, type, triggerAsyncId, resource) {
-      if (id === undefined && type === 'callback_scope_test') {
+      if (id === undefined && (type === 'callback_scope_test' || type === 'existing_callback_scope_test')) {
         id = asyncId;
       }
     },
@@ -39,8 +39,11 @@ function test (binding) {
   return new Promise(resolve => {
     binding.callbackscope.runInCallbackScope(function () {
       assert(insideHook);
-      hook.disable();
-      resolve();
+      binding.callbackscope.runInPreExistingCbScope(function () {
+        assert(insideHook);
+        hook.disable();
+        resolve();
+      });
     });
   });
 }