eval.mjs

// node --disallow-code-generation-from-strings eval.mjs

console.log(eval("1 + 1"));
// => EvalError: Code generation from strings disallowed for this context

fetch.mjs

// node --experimental-fetch fetch.mjs

const res = await fetch("https://nodejs.org/dist/index.json");
const json = await res.json();
console.log(json[0].version);
// => v17.9.0

primordials.mjs

// node --frozen-intrinsics primordials.mjs

Array.prototype.push = () => {};
// With --frozen-intrinsics:
// => TypeError: Cannot assign to read only property 'push'

const a = [];
a.push(1);
console.log(a);
// Without --frozen-intrinsics:
// => []

proto.mjs

// node --disable-proto=throw proto.mjs

({}).__proto__.isAdmin = true;
// With --disable-proto:
// => Error: Accessing Object.prototype.__proto__ has been disallowed with --disable-proto=throw

const user = {};
console.log(user.isAdmin);
// Without --disable-proto:
// => true

uuid.mjs

// node --experimental-network-imports --experimental-global-webcrypto uuid.mjs

import validateUUID from "https://unpkg.com/[email protected]/dist/esm-node/validate.js";

const uuid = crypto.randomUUID();
console.log(validateUUID(uuid)); // => true