throttle with recurring

throttle_with_recurring.js

const throttleWithRecurring = function(fn, delay, options = {}) {
  let timeoutId
  let lastTimeCalled
  let lastArguments

  const startLoop = function(...args) {
    lastArguments = args

    if (!timeoutId) {
      fn(...args)

      timeoutId = setTimeout(() => {
        timeoutId = null

        if (options.recurring) {
          startLoop(...args)
        } else if (lastTimeCalled) {
          fn(...args)
        }
      }, delay)
    } else {
      lastTimeCalled = new Date()
    }
  }

  startLoop.flush = function() {
    startLoop.cancel()

    startLoop(...lastArguments)
  }

  startLoop.cancel = function() {
    clearTimeout(timeoutId)
    timeoutId = null
  }

  return startLoop
}