When does the "experimental fetch" warning get emitted?

[Josh-Cena]

Node version: 18.0.0

We use the following seemingly benign code (source):

const sandbox = {};

Object.getOwnPropertyNames(global).forEach((name) => {
  sandbox[name] = global[name];
});

However, it triggers the experimental warning:

(node:49829) ExperimentalWarning: The Fetch API is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)

What's interesting is that the following ones don't:

const sandbox = {};

["fetch"].forEach((name) => {
  sandbox[name] = global[name];
});

Object.getOwnPropertyNames(global).forEach((name) => {
  console.log(name);
});

But this does:

Object.getOwnPropertyNames(global)
  .filter((name) => name !== "fetch")
  .forEach((name) => {
    sandbox[name] = global[name];
  });

I'd like to know what the condition for emitting the experimental warning is.

[Josh-Cena]

Upgrading to 18.1.0 removes the warning... Maybe it was a bug?

Oh, nvm, the warning is coming from accessing Response and friends, which is fixed in #42807 🤦‍♂️