Run function only when the condition is met

wait-for.ts

interface IWaitForArgs {
  test: () => boolean // run function only if test() returns true
  interval: number
  count: number // should be 0, required
  maxAttempts: number // max number of attempts
  run: () => any // function to run
}

function waitFor({test, interval, count, maxAttempts, run}: IWaitForArgs) {
  // try to run function only maxAttempts times
  if (maxAttempts === count) {
    return
  }
  // Check if condition met. If not, re-check later.
  while (test() !== true) {
    count++
    setTimeout(() => {
      waitFor({test, interval, count, maxAttempts, run})
    }, interval)
    return
  }
  // Condition finally met. run() can be executed.
  run()
}

export default waitFor