// WaitFor calls fn (once in tick) until it passes or timeout expired.
//
// Attempt is failed if any of following methods called in fn:
//  - Fail/FailNow
//  - Error/Errorf
//  - Fatal/Fatalf
// Otherwise attempt is considered as successful and WaitFor stops.
//
// WaitFor receives test object as the first argument.
// It is passed to fn only on the last attempt. All other attempts use fakeT.
// So the test will fail only after timeout expired.
//
// Note: t.Log() and other methods will print to stdout only on the last attempt.
func WaitFor(t TestingT, timeout time.Duration, tick time.Duration, fn func(t TestingT)) {
	timer := time.NewTimer(timeout)
	ticker := time.NewTicker(tick)
	defer timer.Stop()
	defer ticker.Stop()
	for {
		ft := &fakeT{name: t.Name()}
		didPanic := false
		func() {
			defer func() {
				if recover() != nil {
					didPanic = true
				}
			}()
			fn(ft)
		}()
		if !ft.Failed() && !didPanic {
			return
		}

		select {
		case <-timer.C:
			fn(t)
			return
		case <-ticker.C:
		}
	}
}