format.js

let fs = require('fs');
let s = fs.readFileSync(0).toString();

let lvl = 0;
let i = 0;
while (i < s.length) {
    if (s[i] == '(') {
        if (s[i+1] == ')') {
            process.stdout.write('()');
            i += 2;
            continue;
        }
        lvl += 4;
        process.stdout.write(' ');
        process.stdout.write(s[i]);
        process.stdout.write('\n');
        for (let j = 0; j < lvl; j++) {
            process.stdout.write(' ');
        }
    } else if (s[i] == ')') {
        lvl -= 4;
        process.stdout.write('\n');
        for (let i = 0; i < lvl; i++) {
            process.stdout.write(' ');
        }
        process.stdout.write(s[i]);
    } else if (s[i] == ',') {
        process.stdout.write(s[i]);
        process.stdout.write(' ');
    } else {
        process.stdout.write(s[i]);
    }
    i += 1;
}