`vm`: `constants` is undefined about node HOT 6 CLOSED

It is available if you use default import:

import vm from "node:vm";

But it does seem like a bug that it isn't exposed as a named export (maybe because it's experimental?).

from node.

Can't reproduce:

$ cat test.mjs
import { constants } from 'node:vm';
console.log(constants);

$ node test.mjs
[Object: null prototype] {
  USE_MAIN_CONTEXT_DEFAULT_LOADER: Symbol(vm_dynamic_import_main_context_default)
}

from node.

import { constants } from 'node:vm';
console.log(constants);

Using your same code:

$ node test.mjs
[Object: null prototype] {
  USE_MAIN_CONTEXT_DEFAULT_LOADER: Symbol(vm_dynamic_import_main_context_default)
}
# used `require` here
$ node test.cjs
[Object: null prototype] {
  USE_MAIN_CONTEXT_DEFAULT_LOADER: Symbol(vm_dynamic_import_main_context_default)
}

Both worked. I am now a tadbit confused, when I build my project and compile to bytecode, I am using the vm later on to interpret it. constants in my bytecode loader script is undefined. But it works when I just create a script in my project and node ./test.cjs directly.

This is some of the bytecode loader code:

const fs = require("fs");
const path = require("path");
const {Script,constants} = require("node:vm");
const v8 = require("v8");
const Module = require("module");
v8.setFlagsFromString("--no-lazy");
v8.setFlagsFromString("--no-flush-bytecode");
const FLAG_HASH_OFFSET = 12;
const SOURCE_HASH_OFFSET = 8;
let dummyBytecode;
console.log(constants); // logs 'undefined'
function setFlagHashHeader(bytecodeBuffer) {
  if (!dummyBytecode) {
    const script = new Script("", {
      produceCachedData: true,
      // trying to actually use it here
    });
    dummyBytecode = script.createCachedData();
  }
  dummyBytecode.slice(FLAG_HASH_OFFSET, FLAG_HASH_OFFSET + 4).copy(bytecodeBuffer, FLAG_HASH_OFFSET);
};
// ....

from node.

Maybe somehow you are not using the right version of Node.js that has vm.constants to load it?

from node.

Maybe somehow you are not using the right version of Node.js that has vm.constants to load it?

Running process.versions.node pretty much answered it. I am using version 20 at runtime, but my version is 22. Not sure how to force an upgrade, I tried nvmrc, npmrc, engine strict, and engines config but they didn't do it. Might be a case of my project dependencies bundled with node 20?

from node.

Hi, it seems the issue was resolved, but if anyone disagrees, please re open this issue

from node.