function randomInteger(min, max) {
  let rand = min - 0.5 + Math.random() * (max - min + 1);
  return Math.round(rand);
}

let arrLen = randomInteger(1, 10);
if (arrLen % 2 !== 0 ) {
    arrLen++;
}

let arr = [];
let posBalance = arrLen / 2;
let negBalance = arrLen / 2;
for (let i = 0; i < arrLen; i++) {
    let num = randomInteger(-100, 100);
    if (num > 0) {
        if (posBalance > 0) {
            arr[i] = num;
            posBalance--;
        } else {
            arr[i] = -num;
            negBalance--;
        }
    }
    if (num < 0) {
        if (negBalance > 0) {
            arr[i] = num;
            negBalance--;
        } else {
            arr[i] = -num;
            posBalance--;
        }
    }
}
console.log(arr);