transform.js

var through = require('through2');
var tr = through(write, end);

function write(buf, encoding, next){
    setTimeOut(() => {
        this.push(buf.toString().toUpperCase());
        next();
    }, 10000)
}

function end(done){
     process.stdin.pipe(tr).pipe(process.stdout);   
    done(); 
}

process.stdin.pipe(tr).pipe(process.stdout);