go语言设计模式之Concurrency future

package future

type SuccessFunc func(string)
type FailFunc func(error)
type ExecuteStringFunc func() (string, error)

type MaybeString struct {
	successFunc SuccessFunc
	failFunc    FailFunc
}

func (s *MaybeString) Success(f SuccessFunc) *MaybeString {
	s.successFunc = f
	return s
}

func (s *MaybeString) Fail(f FailFunc) *MaybeString {
	s.failFunc = f
	return s
}

func (s *MaybeString) Execute(f ExecuteStringFunc) {
	go func(s *MaybeString) {
		str, err := f()
		if err != nil {
			s.failFunc(err)
		} else {
			s.successFunc(str)
		}
	}(s)
}

package future

import (
	"errors"
	"sync"
	"testing"
	"time"
)

func TestStringOrError_Execute(t *testing.T) {
	future := &MaybeString{}
	t.Run("Success result", func(t *testing.T) {
		var wg sync.WaitGroup
		wg.Add(1)
		go timeout(t, wg)
		future.Success(func(s string) {
			t.Log(s)
			wg.Done()
		}).Fail(func(e error) {
			t.Fail()
			wg.Done()
		})
		future.Execute(func() (string, error) {
			return "Hello World!", nil
		})
		wg.Wait()
	})
	t.Run("Error result", func(t *testing.T) {
		var wg sync.WaitGroup
		wg.Add(1)
		future.Success(func(s string) {
			t.Fail()
			wg.Done()
		}).Fail(func(e error) {
			t.Log(e.Error())
			wg.Done()
		})
		future.Execute(func() (string, error) {
			return "", errors.New("Error ocurred")
		})
		wg.Wait()
	})
}

func timeout(t *testing.T, wg sync.WaitGroup) {
	time.Sleep(time.Second)

	t.Log("Timeout")
	t.Fail()
	wg.Done()
}