Endo Exec

Importing endo-exec declares that if module executed directly as a script, it will run in a Hardened JS start compartment. It opts for compatibility with legacy code when possible.

NOTE: if you want precise control over how Endo is initialized, especially if you are writing an application that needs to use mixed Compartments (both trusted libraries and untrusted code), you should NOT use this package. Instead, have a look at @endo/init.

Import endo-exec like:

#! /usr/bin/env node
import 'endo-exec';

console.log('Hello, Endo world!');

Object.prototype.monkeyPatch = 53;
// (TypeError#1)
// TypeError#1: Cannot add property monkeyPatch, object is not extensible
//  at main (file:///Users/michael/agoric/endo/packages/syrup/a.js:6:32)
//  at /Users/michael/agoric/endo/packages/endo-exec/endo-exec.cjs:22:15

Or if you want to have your script be importable without side-effects (ocap discipline), then avoid top-level module state and export a main entrypoint that can be executed on demand.

#! /usr/bin/env node
import 'endo-exec';

import { promises as fs } from 'fs';

/** @type {import('endo-exec').Main} */ 
export const main = async ([script, file]) => {
  console.log('Hello from', script);
  await fs.readFile(file);
  console.log(`Here's the file`, file);
};