Reading child process using node

read_child_process.js

// node --experimental-default-type=module read_child_process.js
import { spawn } from "node:child_process";
import { Duplex } from "node:stream";

const [command, args] = ["python3", ["./stream.py"]];
const { stdout, stderr } = spawn(command, args);
const { readable, writable } = Duplex.toWeb(stdout);
console.log(readable, writable);
/*
const data = await new Response(readable).text();
console.log(data);
*/

await readable.pipeTo(
  new WritableStream({
    write(value) {
      console.log(value);
    },
    close() {
      console.log(`${command} pipe closed.`);
    }
  })
).catch(console.error);

stream.py

#!/usr/bin/env -S python3 -u
from random import choice
from string import digits
import itertools
import os
import sys

for chunk in iter(lambda: ''.join(choice(digits) for i in range(512)).encode(), b''):
    if chunk is not None:
        sys.stdout.buffer.write(chunk)
        sys.stdout.buffer.flush()  
        break