"use strict";

const ERROR_RATE = 0.25

function should_fail () {
  return Math.random() < ERROR_RATE
}

function main(params) {
  if (!params.a || !params.b) throw new Error('Missing input parameters (a or b).')
  if (should_fail()) throw new Error('failed!')

  const sum = params.a + params.b
  return { sum }
}