errGroups-waitGroups.go

//ErrorGroup vs WaitGroup
//Gist for an article for my portfolio

//WaitGroup Approach
func checkOne(n int) error {
	if n != 1 {
		return errors.New("number not one")
	}
	return nil
}

func main() {
	numbers := []int{1, 1, 1, 5}

	var wg sync.WaitGroup
	// create channel to handle errors
	errChan := make(chan error, 1)

	for _, number := range numbers {
		number := number
		wg.Add(1)
		go func() {
			defer wg.Done()
			err := checkOne(number)
			if err != nil {
				// send error through the channel
				errChan <- err
				return
			}
		}()
	}

	go func() {
		wg.Wait()
		// close channel after all goroutines are done
		close(errChan)
	}()

	// read channel to get the error
	err := <-errChan
	if err != nil {
		fmt.Println(err.Error())
	}
}


//ErrorGroup Approach
func checkOne(n int) error {
	if n != 1 {
		return errors.New("number not one")
	}
	return nil
}

func main() {
	numbers := []int{1, 1, 1, 5}

	// create new error group
	eg := new(errgroup.Group)
	for _, number := range numbers {
		number := number
		eg.Go(func() error {
			return checkOne(number)
		})
	}
	if err := eg.Wait(); err != nil {
		fmt.Println(err.Error())
	}
}