Node.js IO pipes with c++ child_process

--parent.js

const { execFile } = require('child_process');
const child = execFile('child-cpp');

process.stdin.setEncoding('utf8');

process.stdin.on('readable', () => {
  const chunk = process.stdin.read();
  if (chunk !== null) {
    //parent.stdin as child.stdin;
	child.stdin.write(chunk);
  }
});

//child.stdout to parent stdout
child.stdout.on('data', (chunk) => {
  process.stdout.write(chunk);
});

-child.cpp

#include <iostream>

int main()
{
	
	double result = 0, input = 0;
	while(std::cout<<"input: " && std::cin >> input){

		if (input == 0) return 0;
		
		result += input;
		std::cout<<"result: "<<result<<std::endl;
	}

	return 0;
}

output.txt

$> node parent.js
-----------------
input: 2
result: 2
input: 3
result: 5
input: 6
result: 11
input:

thx random ppl on the internet