Retry a function the specified times

retry.js

async function retry(fn, times = 0, ...args) {
  if (typeof times !== 'number') throw new Error('times must be a number')
  if (times < 0) throw new Error('times must not be less than 0')
  const totalTimes = times + 1
  let result
  let firstError
  let i = 0
  for (; i < totalTimes; i++) {
    try {
      result = await fn(...args)
      break
    } catch (err) {
      if (!firstError) firstError = err
    }
  }
  if (i === totalTimes && firstError) throw firstError
  return result
}

Example:

async function foo (k) {
  const n = Math.random()
  console.log(`n: ${n}, k: ${k}`)
  if (n < k) {
    throw new Error(`must not be less than ${k}`)
  }
  return n
}

console.log(retry(foo, 3, 0.5))