freighthub-cummulative-ttl.js

const requests = [
  {requestId: 't2', startedAt: 1489744808, ttl: 8},
  {requestId: 't3', startedAt: 1489744803, ttl: 3},
  {requestId: 't1', startedAt: 1489744806, ttl: 12},
  {requestId: 't4', startedAt: 1489744810, ttl: 1}
];


let min = requests[0].startedAt;
let max = 0;

requests.forEach(request => {
  const completeAt = request.startedAt + request.ttl;
  if (request.startedAt < min) {
    min = request.startedAt;
  }
  if (completeAt > max) {
    max = completeAt;
  }
});

const cummulativeTtl = (max - min);

console.log(cummulativeTtl);

let requests = [
  {requestId: 'poiax',  startedAt: 1489744808, ttl: 8},
  {requestId: 'kdfhd',  startedAt: 1489744803, ttl: 3},
  {requestId: 'uqwyet', startedAt: 1489744806, ttl: 12}, 
  {requestId: 'qewaz',  startedAt: 1489744810, ttl: 1}
]

const cumulative = (requests) => Math.max.apply(Math, requests.map(req => req.startedAt + req.ttl)) - Math.min.apply(Math, requests.map(req => req.startedAt));


let r = cumulative(requests);

console.log(r);

@vhuerta That's one unreadable piece of code = )