instanceof Array of array from vm script not working

[joshxyzhimself]

Hi, is this the expected behaviour?

Was expecting test_data.test_array instanceof Array to return true

const vm = require('vm');
const test_data = new vm.Script(`
  test_data = { test_array: [] };
`).runInNewContext();

console.log(JSON.stringify({ test_data }, null, 2));
// {
//   "test_data": {
//     "test_array": []
//   }
// }

console.log(typeof test_data.test_array);
// object

console.log(test_data.test_array instanceof Array);
// false, should be true

[Trott]

runInNewContext() means that the Array in the new context is different from the Array in the calling context so this behavior is expected. It's similar to the way instanceof doesn't work as you might expect when using data in iframes in the browser.

[Trott]

I'm going to close but there's more info at nodejs/node-v0.x-archive#1277 including a note that Array.isArray() is probably what you want to use.

[joshxyzhimself]

That makes sense lol, should've googled more. Thanks a lot @Trott!