a.js

import { spawn as nodeSpawn } from "child_process";
import { fileURLToPath } from "url";

const __filename = fileURLToPath(import.meta.url);

async function spawn() {
  return new Promise((resolve, reject) => {
    const proc = nodeSpawn("cat", [__filename], {
      stdio: ["ignore", "ignore", "ignore"],
      shell: false,
    });

    proc.on("exit", code => {
      resolve();
    });

    proc.on("error", err => {
      reject(err);
    });
  });
}

async function spawn100() {
  const procs = [];
  for (let i = 0; i < 100; i++) {
    procs.push(spawn());
  }
  await Promise.all(procs);
}

var i = 0;

const fmt = new Intl.NumberFormat();

while (i <= 1000) {
  const memUsage = (process.memoryUsage.rss() / 1024 / 1024) | 0;
  console.log(
    `\x1b[36mRSS:\x1b[0m \x1b[33m${memUsage}MB\x1b[0m \x1b[36mafter\x1b[0m \x1b[32m${fmt.format(i++ * 100)}\x1b[0m \x1b[36m\x1b[0m`,
  );
  await spawn100();
}

Kill the child

so many cats

meow