Gin Gonic在发送无效数据时自定义错误消息失败。

huangapple
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英文:

Gin Gonic Custom Error Message Fails When Invalid Data Sent

问题

Validator结构体

  1. type RegisterValidator struct {
  2. 	Name              string     `form:"name" json:"name" binding:"required,min=4,max=50"`
  3. 	Email             string     `form:"email" json:"email" binding:"required,email,min=4,max=50"`
  4. 	Password          string     `form:"password" json:"password" binding:"required,min=8,max=50"`
  5. 	MobileCountryCode int        `form:"mobile_country_code" json:"mobile_country_code" binding:"required,gte=2,lt=5"`
  6. 	Mobile            int        `form:"mobile" json:"mobile" binding:"required,gte=5,lt=15"`
  7. 	UserModel         users.User `json:"-"`
  8. }

将自定义错误格式化如下：

  1. type CustomError struct {
  2. 	Errors map[string]interface{} `json:"errors"`
  3. }
  5. func NewValidatorError(err error) CustomError {
  6. 	res := CustomError{}
  7. 	res.Errors = make(map[string]interface{})
  8. 	errs := err.(validator.ValidationErrors)
  10. 	for _, v := range errs {
  11. 		param := v.Param()
  12. 		field := v.Field()
  13. 		tag := v.Tag()
  15. 		if param != "" {
  16. 			res.Errors[field] = fmt.Sprintf("{%v: %v}", tag, param)
  17. 		} else {
  18. 			res.Errors[field] = fmt.Sprintf("{key: %v}", tag)
  19. 		}
  20. 	}
  22. 	return res
  23. }

当发送的数据为

  1. {
  2.     "email": "me@example.com",
  3.     "name": "John Doe",
  4.     "mobile_country_code": 1,
  5.     "mobile": 1234567
  6. }

时可以正常工作。

但是当发送一个无效的类型时

  1. {
  2.     "email": "me@example.com",
  3.     "name": "John Doe",
  4.     "mobile_country_code": "1",
  5.     "mobile": 1234567
  6. }

会抛出错误interface conversion: error is *json.UnmarshalTypeError, not validator.ValidationErrors。

这个问题与此问题相关：https://stackoverflow.com/questions/64278486/how-to-assert-error-type-json-unmarshaltypeerror-when-caught-by-gin-c-bindjson
然而，答案并不合理。

英文:

Validator struct

  1. type RegisterValidator struct {
  2. 	Name              string     `form:"name" json:"name" binding:"required,min=4,max=50"`
  3. 	Email             string     `form:"email" json:"email" binding:"required,email,min=4,max=50"`
  4. 	Password          string     `form:"password" json:"password" binding:"required,min=8,max=50"`
  5. 	MobileCountryCode int        `form:"mobile_country_code" json:"mobile_country_code" binding:"required,gte=2,lt=5"`
  6. 	Mobile            int        `form:"mobile" json:"mobile" binding:"required,gte=5,lt=15"`
  7. 	UserModel         users.User `json:"-"`
  8. }

Formatting a custom error as below:

  1. type CustomError struct {
  2. 	Errors map[string]interface{} `json:"errors"`
  3. }
  5. func NewValidatorError(err error) CustomError {
  6. 	res := CustomError{}
  7. 	res.Errors = make(map[string]interface{})
  8. 	errs := err.(validator.ValidationErrors)
  10. 	for _, v := range errs {
  11. 		param := v.Param()
  12. 		field := v.Field()
  13. 		tag := v.Tag()
  15. 		if param != "" {
  16. 			res.Errors[field] = fmt.Sprintf("{%v: %v}", tag, param)
  17. 		} else {
  18. 			res.Errors[field] = fmt.Sprintf("{key: %v}", tag)
  19. 		}
  20. 	}
  22. 	return res
  23. }

works when data sent is

  1. {
  2.     "email": "me@example.com",
  3.     "name": "John Doe",
  4.     "mobile_country_code": 1,
  5.     "mobile": 1234567
  6. }

but sending an invalid type

  1. {
  2.     "email": "me@example.com",
  3.     "name": "John Doe",
  4.     "mobile_country_code": "1",
  5.     "mobile": 1234567
  6. }

throws the error interface conversion: error is *json.UnmarshalTypeError, not validator.ValidationErrors

This question is related to this one: https://stackoverflow.com/questions/64278486/how-to-assert-error-type-json-unmarshaltypeerror-when-caught-by-gin-c-bindjson
however the answers do not make sense.

答案1

得分: 2

根据异常提示，以下代码行无法进行类型转换：

  1. errs := err.(validator.ValidationErrors)

函数中传入了一个不是 *validator.ValidationErrors 类型的错误。

因此，要么确保其他类型的错误不会传递给 NewValidatorError 函数，要么进行更安全的类型检查，例如：

  1. errs, ok := err.(validator.ValidationErrors)
  2. if !ok {
  3.   // 处理其他错误类型
  4. }

更多信息：A Tour of Go - 类型断言，A Tour of Go - 类型切换

英文:

As the exception suggests, the following line failed type conversion

  1.     errs := err.(validator.ValidationErrors)

A different type of error must have got passed into the function that is not validator.ValidationErrors.

So either make sure other errors won't be passed into NewValidatorError. Or do a safer type check like:

  1. errs, ok := err.(validator.ValidationErrors)
  2. if !ok {
  3.   // handles other err type
  4. }

More info: A Tour of Go - type assertions, A Tour of Go - type switches

答案2

得分: -1

我为UnmarshalTypeError添加了一个检查，代码如下：

  1. if reflect.TypeOf(err).Elem().String() == "json.UnmarshalTypeError" {
  2.     errs := err.(*json.UnmarshalTypeError)
  3.     res.Errors[errs.Field] = fmt.Sprintf("{key: %v}", errs.Error())
  5.     return res
  6. }
  8. errs := err.(validator.ValidationErrors)

我猜Golang在对JSON进行类型提示时是严格的。它必须是精确的类型，否则会抛出UnmarshalTypeError错误。

英文:

I added a check for the UnmarshalTypeError as below:

  1. 	if reflect.TypeOf(err).Elem().String() == "json.UnmarshalTypeError" {
  2. 		errs := err.(*json.UnmarshalTypeError)
  3. 		res.Errors[errs.Field] = fmt.Sprintf("{key: %v}", errs.Error())
  5. 		return res
  6. 	}
  8. 	errs := err.(validator.ValidationErrors)

I guess Golang is strict when json is type-hinted. It has to be the exact type otherwise it will throw an UnmarshalTypeError error.

huangapple
  • 本文由 发表于 2021年9月29日 04:08:11
  • 转载请务必保留本文链接：https://go.coder-hub.com/69367914.html
  • go
  • go-gin
  • validation
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