kben19

type Wallet struct {
	money int
}

func (wallet *Wallet) MyMoney() {
	fmt.Println("$", wallet.money)
}

func (wallet *Wallet) AddMoney(money int) {
	wallet.money += money

kben19

db, err := sql.Open()
if err != nil {
   log.Fatal(err)
}

tx, err := db.Begin()
if err != nil {
   log.Fatal(err)
}
defer func() {

kben19

db, err := sql.Open()
if err != nil {
   log.Fatal(err)
}
defer func (){
   if errDB := db.Close(); errDB != nil {
      log.Fatal(errDB)
   }
}

kben19

type generalError struct {
   text string
   code CodeStatus
}

func (error *generalError) Error() string {
   return fmt.Sprintf("%s %d", error.text, error.code)
}

func NewError(text string) error {

kben19

type WarehouseItf interface {
  GetProduct(id int) (Product, error)
  InsertProduct(product Product) error
}

type Retail struct {
  warehouse WarehouseItf 
}

func (retail *Retail) GetMyProduct() ([]Product, error) {

kben19

import "errors"

type WarehouseMock struct {}

func(warehouse *WarehouseMock) GetProduct(id int) (Product, error){
  if id != 1 {
    return Product{}, errors.New("test")
  }
  return Product{}, nil
}

kben19

package formatter

// golangJSONItf interface implements all the functions of GolangJSON.
type golangJSONItf interface {
	Marshal(v interface{}) ([]byte, error)
}

// Formatter uses local json library wrapper rather than encoding/json.
type Formatter struct {
  golangJSON golangJSONItf

kben19

import (
  "net/http"
  "time"
)

func main() {
  httpClient := &http.Client{Timeout: time.Duration(3) * time.Second}
  cacheService := NewCache()
  service := NewService(httpClient, cacheService)
  

kben19

func (wrapper *ServiceWrapper) GetProductStock(id int) (stock int, err error) {
  key := fmt.Sprintf("key-%d", id)
  value, err := wrapper.cache.Get(key)
  if err == nil && value != "" {
    stock, _ = strconv.Atoi(value)
    return
  }
  
  defer func () {
    _ = wrapper.cache.Set(key, strconv.Itoa(stock))

kben19

func (wrapper *ServiceWrapper) GetProductStock(id int) (int, error) {
  // Get Version 2
  if id > 100 {
    return wrapper.service.GetProductStockV2(id)
  }
  
  // Otherwise, use the old version
  return wrapper.service.GetProductStock(id)
}