errgroup.go

package main

import (
	"fmt"
	"golang.org/x/sync/errgroup"
	"time"
)

func main() {
	fmt.Println("Hello, world!")

	eg := new(errgroup.Group)

	eg.Go(asyncOne)
	eg.Go(asyncTwo)

	if err := eg.Wait(); err != nil {
		fmt.Println("Encountered error:", err)
	}

	fmt.Println("Bye bye")
}

func asyncOne() error {
	time.Sleep(3 * time.Second)
	fmt.Println("async one")
	return fmt.Errorf("Error happened")
}

func asyncTwo() error {
	time.Sleep(1 * time.Second)
	fmt.Println("async two")
	return nil
}

❯ go run main.go
Hello, world!
async two
async one
Encountered error: Error happened
Bye bye