host.mjs

import { Sandbox } from "./sandbox.mjs"
import fs from 'fs'
import assert from 'assert'

const dummyConsole = {
  log: (s) => {
    console.log(s)
  }
}
const globalThis = { console: dummyConsole };

begin();
resume();

function begin() {
  const sandbox = new Sandbox({ globalThis });

  const appText = fs.readFileSync('app.js', 'utf-8');
  const { incr } = sandbox.evaluateCommonJsModule(appText);

  assert.equal(incr(), 1);
  assert.equal(incr(), 2);
  assert.equal(incr(), 3);

  console.log('Saving snapshot');
  const snapshot = sandbox.takeSnapshot({ incr });
  fs.writeFileSync('snapshot.bin', snapshot);

  const { ioJournal, exportList } = JSON.parse(snapshot.toString('utf-8'));
  fs.writeFileSync('ioJournal.json', JSON.stringify(ioJournal, null, 2));
}

function resume() {
  console.log('Resuming from snapshot');

  const snapshot = fs.readFileSync('snapshot.bin');
  const { incr } = Sandbox.restoreFromSnapshot(snapshot, { globalThis });

  assert.equal(incr(), 4);
  assert.equal(incr(), 5);
  assert.equal(incr(), 6);
}