context-1.go

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		fmt.Println("Let's wait 5 minute")
		WaitUntilWithContext(ctx, time.Minute*5)
		fmt.Println("Hey!! Why we exited after 5 second !?!??!")
	}()
	time.Sleep(5 * time.Second)
	cancel()
	time.Sleep(10 * time.Second)
}

func WaitUntilWithContext(ctx context.Context, diff time.Duration) {
	timer := time.NewTimer(diff)
	defer timer.Stop()

	select {
	case <-timer.C:
		return
	case <-ctx.Done():
		return
	}
}