weighted allocation example

weights.js

/*
This can be used when we need to move to a front end that only delivers the
users and their allocation percentage
salesReps is the sample array we would get from the DB. 
*/

const salesReps = [
  {name: "Renee", id:"30761006", allocation: 70},
  {name: "Emma", id:"33620479", allocation: 10},
  {name: "Marian", id:"33495420", allocation: 10},
  {name: "Jade", id:"30455396", allocation: 10},
]

let weightTotal = salesReps.reduce((tally, rep) => {
  return tally += rep.allocation
}, 0)

const allocateRep = () => {
  let luckyNumber = Math.floor(Math.random() * weightTotal)
  return salesReps.find(rep => {
    luckyNumber -= rep.allocation
    if (luckyNumber <= 0) {
      return rep.name
    }
  })
}



// Proof
const test = () => {
  index = 0
  itterations = 10000000
  results = []

  while (index++ < itterations) {
    results.push(allocateRep().name)
  }

  const count = results.reduce((tally, result) => {
    tally[result] = (tally[result] || 0) + 1
    return tally
  }, {})

  console.log(count)
}

test()