Functional interpolation

interpolation.js

const cols = [{ ts: 1 }, { ts: 5 }, { ts: 6 }]
const smallest = 1
const interpolatedCols = cols.reduce((accumulated, current) => {
  const prev = accumulated[accumulated.length - 1]
  for (let i = prev.ts + smallest; i <= current.ts; i += smallest) {
    const element = { ts: i }
    accumulated.push(element)
  }
  return accumulated
}, [cols[0]])