optimize code of custom error structure

common/errcode/code.go

@@ -1,73 +0,0 @@
-// Package errcode provides internal error definition and business error definition
-package errcode
-
-import (
-	"net/http"
-)
-
-// 此处为公共的错误码, 预留 10000000 ~ 10000099 间的 100 个错误码
-var (
-	Success            = newError(0, "success")
-	ErrServer          = newError(10000000, "服务器内部错误")
-	ErrParams          = newError(10000001, "参数错误, 请检查")
-	ErrNotFound        = newError(10000002, "资源未找到")
-	ErrPanic           = newError(10000003, "(*^__^*)系统开小差了,请稍后重试") // 无预期的panic错误
-	ErrToken           = newError(10000004, "Token无效")
-	ErrForbidden       = newError(10000005, "未授权") // 访问一些未授权的资源时的错误
-	ErrTooManyRequests = newError(10000006, "请求过多")
-	ErrCoverData       = newError(10000007, "ConvertDataError") // 数据转换错误
-)
-
-// 各个业务模块自定义的错误码, 从 10000100 开始, 可以按照不同的业务模块划分不同的号段
-// Example:
-//var (
-//	ErrOrderClosed  = NewError(10000100, "订单已关闭")
-//)
-
-// 用户模块相关错误码 10000100 ~ 1000199
-var (
-	ErrUserInvalid      = newError(10000101, "用户异常")
-	ErrUserNameOccupied = newError(10000102, "用户名已被占用")
-	ErrUserNotRight     = newError(10000103, "用户名或密码不正确")
-)
-
-// 商品模块相关错误码 10000200 ~ 1000299
-var (
-	ErrCommodityNotExists = newError(10000200, "商品不存在")
-	ErrCommodityStockOut  = newError(10000201, "库存不足")
-)
-
-// 购物车模块相关错误码 10000300 ～ 1000399
-var (
-	ErrCartItemParam = newError(10000300, "购物项参数异常")
-	ErrCartWrongUser = newError(10000301, "用户购物信息不匹配")
-)
-
-// 订单模块相关错误码 10000500 ~ 10000599
-var (
-	ErrOrderParams              = newError(10000500, "订单参数异常")
-	ErrOrderCanNotBeChanged     = newError(10000501, "订单不可修改")
-	ErrOrderUnsupportedPayScene = newError(10000502, "支付场景暂不支持")
-)
-
-func (e *AppError) HttpStatusCode() int {
-	switch e.Code() {
-	case Success.Code():
-		return http.StatusOK
-	case ErrServer.Code(), ErrPanic.Code():
-		return http.StatusInternalServerError
-	case ErrParams.Code(), ErrUserInvalid.Code(), ErrUserNameOccupied.Code(), ErrUserNotRight.Code(),
-		ErrCommodityNotExists.Code(), ErrCommodityStockOut.Code(), ErrCartItemParam.Code(), ErrOrderParams.Code():
-		return http.StatusBadRequest
-	case ErrNotFound.Code():
-		return http.StatusNotFound
-	case ErrTooManyRequests.Code():
-		return http.StatusTooManyRequests
-	case ErrToken.Code():
-		return http.StatusUnauthorized
-	case ErrForbidden.Code(), ErrCartWrongUser.Code(), ErrOrderCanNotBeChanged.Code():
-		return http.StatusForbidden
-	default:
-		return http.StatusInternalServerError
-	}
-}

common/errcode/error.go

@@ -10,12 +10,12 @@ import (
 
 var codes = map[int]struct{}{}
 
-// AppError define struct of internal error
+// AppError define struct of internal error. occurred field records the location where the error is triggered
 type AppError struct {
 	code     int
 	msg      string
 	cause    error
-	occurred string // 保存由底层错误导致AppErr发生时的位置
+	occurred string
 }
 
 func (e *AppError) Error() string {
@@ -49,10 +49,6 @@ func (e *AppError) Cause() error {
 }
 
 // WithCause define func return top level predefined errors,where the cause field contains the underlying base error
-// 在逻辑执行中出现错误, 比如dao层返回的数据库查询错误
-// 可以在领域层返回预定义的错误前附加上导致错误的基础错误。
-// 如果业务模块预定义的错误码比较详细, 可以使用这个方法, 反之错误码定义的比较笼统建议使用Wrap方法包装底层错误生成项目自定义Error
-// 并将其记录到日志后再使用预定义错误码返回接口响应
 func (e *AppError) WithCause(err error) *AppError {
 	newErr := e.Clone()
 	newErr.cause = err
@@ -61,8 +57,6 @@ func (e *AppError) WithCause(err error) *AppError {
 }
 
 // Wrap define func packaging information and errors returned by the underlying logic
-// 用于逻辑中包装底层函数返回的error 和 WithCause 一样都是为了记录错误链条
-// 该方法生成的error 用于日志记录, 返回响应请使用预定义好的error
 func Wrap(msg string, err error) *AppError {
 	if err == nil {
 		return nil
@@ -77,7 +71,7 @@ func (e *AppError) UnWrap() error {
 	return e.cause
 }
 
-// Is define func return result of whether  any error in err's tree matches target. implemented to support errors.Is(err, target)
+// Is define func return result of whether any error in err's tree matches target. implemented to support errors.Is(err, target)
 func (e *AppError) Is(target error) bool {
 	targetErr, ok := target.(*AppError)
 	if !ok {
@@ -86,6 +80,17 @@ func (e *AppError) Is(target error) bool {
 	return targetErr.Code() == e.Code()
 }
 
+// As define func return result of whether any error in err's tree matches target. implemented to support errors.As(err, target)
+func (e *AppError) As(target any) bool {
+	t, ok := target.(**AppError)
+	if !ok {
+		return false
+	}
+
+	*t = e
+	return true
+}
+
 // Clone define func return a new AppError with source AppError's code, msg, cause, occurred
 func (e *AppError) Clone() *AppError {
 	return &AppError{
@@ -107,7 +112,7 @@ func newError(code int, msg string) *AppError {
 	return &AppError{code: code, msg: msg}
 }
 
-// getAppErrOccurredInfo 获取项目中调用Wrap或者WithCause方法时的程序位置, 方便排查问题
+// getAppErrOccurredInfo define func return the location where the error is triggered
 func getAppErrOccurredInfo() string {
 	pc, file, line, ok := runtime.Caller(2)
 	if !ok {
@@ -140,7 +145,7 @@ type formattedErr struct {
 	Occurred string      `json:"occurred"`
 }
 
-// toStructuredError 在JSON Encode 前把Error进行格式化
+// toStructuredError define func convert AppError to structured error for better readability
 func (e *AppError) toStructuredError() *formattedErr {
 	fe := new(formattedErr)
 	fe.Code = e.Code()