V8 stackoverflow question

testcase.cpp

/* 
In my case, compile with:

/usr/bin/c++ --std=c++14 -I${PWD}/include testcase2.cpp -o testcase -L$PWD/lib $PWD/lib/libv8_base.a -lv8_libbase $PWD/lib/libv8_nosnapshot.a -lv8_libplatform $PWD/lib/libv8_libsampler.a -licui18n -licuuc -Wl,-rpath,$PWD/lib -pthread

Run with ./testcase
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "include/libplatform/libplatform.h"
#include "include/v8.h"
#include <iostream>
#include <string>

using namespace v8;

void construct_with_non_ec6_syntax(const FunctionCallbackInfo<Value>& args) {
    Handle<Object> global = args.GetIsolate()->GetCurrentContext()->Global();
    std::string newvecfunc = "some_non_ec6_class";
    Handle<Value> value = global->Get(String::NewFromUtf8(args.GetIsolate(), newvecfunc.c_str(), String::kNormalString, newvecfunc.length()));
    Local<Value> result;
    if (value->IsFunction()) {
        Handle<Function> func = Handle<Function>::Cast(value);
        Handle<Value> args2[2];
        args2[0] = Number::New(args.GetIsolate(), 111);
        args2[1] = Number::New(args.GetIsolate(), 222);
        result = func->CallAsConstructor(args.GetIsolate()->GetCurrentContext(), 2, args2).ToLocalChecked();
    }
    args.GetReturnValue().Set(result);
}
void construct_with_ec6_syntax(const FunctionCallbackInfo<Value>& args) {
    Handle<Object> global = args.GetIsolate()->GetCurrentContext()->Global();
    std::string newvecfunc = "some_ec6_class";
    Handle<Value> value = global->Get(String::NewFromUtf8(args.GetIsolate(), newvecfunc.c_str(), String::kNormalString, newvecfunc.length()));
    Local<Value> result;
    if (value->IsFunction()) {
        Handle<Function> func = Handle<Function>::Cast(value);
        Handle<Value> args2[2];
        args2[0] = Number::New(args.GetIsolate(), 111);
        args2[1] = Number::New(args.GetIsolate(), 222);
        result = func->CallAsConstructor(args.GetIsolate()->GetCurrentContext(), 2, args2).ToLocalChecked();
    }
    args.GetReturnValue().Set(result);
}

int main(int argc, char* argv[]) {
  // Initialize V8.
  V8::InitializeICUDefaultLocation(argv[0]);
  V8::InitializeExternalStartupData(argv[0]);
  Platform* platform = platform::CreateDefaultPlatform();
  V8::InitializePlatform(platform);
  V8::Initialize();
  // Create a new Isolate and make it the current one.
  Isolate::CreateParams create_params;
  create_params.array_buffer_allocator = ArrayBuffer::Allocator::NewDefaultAllocator();
  Isolate* isolate = Isolate::New(create_params);
  
  {
    Isolate::Scope isolate_scope(isolate);
    HandleScope handle_scope(isolate);
    Local<Context> context = Context::New(isolate);
    Context::Scope context_scope(context);
    // Expose a C++ function to V8
    Local<ObjectTemplate> global = ObjectTemplate::New(isolate);
    auto ftpl = FunctionTemplate::New(isolate, construct_with_non_ec6_syntax);
    global->Set(String::NewFromUtf8(isolate, "construct_with_non_ec6_syntax", NewStringType::kNormal).ToLocalChecked(), ftpl);

    auto ftpl2 = FunctionTemplate::New(isolate, construct_with_ec6_syntax);
    global->Set(String::NewFromUtf8(isolate, "construct_with_ec6_syntax", NewStringType::kNormal).ToLocalChecked(), ftpl2);
    context = Context::New(isolate, NULL, global);

    // Using non EC6 syntax
    {
        // Compile and run test function
        Local<String> source = String::NewFromUtf8(isolate, "function some_non_ec6_class(x, y) { this.result = x + y; };", NewStringType::kNormal).ToLocalChecked();
        Local<Script> script = Script::Compile(context, source).ToLocalChecked();
        Local<Value> result = script->Run(context).ToLocalChecked();

        // Invoke test function and print result
        Local<String> source2 = String::NewFromUtf8(isolate, "t = construct_with_non_ec6_syntax(); t.result;", NewStringType::kNormal).ToLocalChecked();
        Local<Script> script2 = Script::Compile(context, source2).ToLocalChecked();
        Local<Value> result2 = script2->Run(context).ToLocalChecked();
        String::Utf8Value utf8(result2);
        printf("%s\n", *utf8); // prints 333.. which is OK! (111 + 222)
    }

    // Using EC6 syntax
    {
        // Compile and run test function
        Local<String> source = String::NewFromUtf8(isolate, "class some_ec6_class { constructor(x, y) { this.result = x + y; } };", NewStringType::kNormal).ToLocalChecked();
        Local<Script> script = Script::Compile(context, source).ToLocalChecked();
        Local<Value> result = script->Run(context).ToLocalChecked();

        // Invoke test function, will throw because `t` is undefined..
        Local<String> source2 = String::NewFromUtf8(isolate, "t = construct_with_ec6_syntax(); t.result;", NewStringType::kNormal).ToLocalChecked();
        Local<Script> script2 = Script::Compile(context, source2).ToLocalChecked();
        Local<Value> result2 = script2->Run(context).ToLocalChecked();
        String::Utf8Value utf8(result2);
        printf("%s\n", *utf8); // should print 333 as well..?
    }
  }
  isolate->Dispose();
  V8::Dispose();
  V8::ShutdownPlatform();
  delete platform;
  delete create_params.array_buffer_allocator;
  return 0;
}
/**
 * Running this program results in the following output;
 * -----------------------------------------------------
 * 333
 * <unknown>:34: Uncaught TypeError: Cannot read property 'result' of undefined
 * 
 * #
 * # Fatal error in v8::ToLocalChecked
 * # Empty MaybeLocal.
 * #
 * 
 * /bin/bash: line 1:  4287 Illegal instruction     (core dumped) ./testcase
**/