README
¶
ext-errors
Package exterrors provides extended error handling primitives to add a bit more info to errors returning from the function.
go get github.com/eugeneradionov/ext-errors
Motivation
In every API that handles HTTP requests, we need to work with error handling.
We'd like to add extra information about the response status and can't figure it out with the standard errors package.
With exterrors package, you know the status of your request in any place of the application.
Usage
Use ExtError interface instead of standard error
func GetUserByID(id string) (User, exterrors.ExtError) {
user, err := db.GetUserByID(id)
if err != nil {
return User{}, exterrors.NewInternalServerError(err)
}
return user, nil
}
func GetUserHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json;charset=utf-8")
user, extErr := GetUserByID("user_id_1")
if extErr != nil {
SendExtError(w, extErr)
return
}
}
func SendExtError(w http.ResponseWriter, extErr exterrors.ExtError) {
var statusCode = extErr.HTTPCode()
w.Header().Set("Content-Type", "application/json;charset=utf-8")
errResp, err := json.Marshal(extErr)
if err != nil {
statusCode = http.StatusInternalServerError
}
w.WriteHeader(statusCode)
w.Write(errResp)
}
Use ExtErrors for handling multiple errors
func GetUsersHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json;charset=utf-8")
extErrs := exterrors.NewExtErrors()
user1, extErr := GetUserByID("user_id_1")
if extErr != nil {
extErrs.Add(extErr)
}
user2, extErr := GetUserByID("user_id_2")
if extErr != nil {
extErrs.Add(extErr)
}
SendExtErrors(w, extErrs)
}
func SendExtErrors(w http.ResponseWriter, extErrs exterrors.ExtErrors) {
var statusCode = extErrs.HTTPCode() // Set the status code according to error type
w.Header().Set("Content-Type", "application/json;charset=utf-8")
errResp, err := json.Marshal(extErrs)
if err != nil {
statusCode = http.StatusInternalServerError
}
w.WriteHeader(statusCode)
w.Write(errResp)
}
Caveats
As ExtError requires implementation of standard error interface to be compatible with it, be careful, when trying to assign function result ExtError to the variable with standard error type.
This could cause unpredictable behavior.
Documentation
¶
Index ¶
- type Error
- type Errors
- type ExtError
- func NewBadRequestError(err error) ExtError
- func NewError(err error, code int, message, field string) ExtError
- func NewForbiddenError(err error) ExtError
- func NewInternalServerErrorError(err error) ExtError
- func NewNotFoundError(err error, field string) ExtError
- func NewUnauthorizedError(err error) ExtError
- func NewUnprocessableEntityError(err error, field string) ExtError
- type ExtErrors
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Error ¶
type Error struct {
// Code contains info about HTTP code
// that could be sent in the status of the HTTP response.
Code int `json:"-"`
// Message contains error message if any.
Message string `json:"message,omitempty"`
// Description contains detailed error information if any.
Description string `json:"description,omitempty"`
// Field describes in which field an error has occurred if any.
// For example JSON field in the HTTP request body.
// Typically is used for pointing an invalid field during validation.
Field string `json:"field,omitempty"`
}
Error contains extended error information.
func (Error) ErrDescription ¶
func (Error) ErrMessage ¶
func (Error) MarshalJSON ¶
type Errors ¶
type Errors struct {
Errs []ExtError `json:"errors"`
}
Errors represents multiple errors occurred. Useful for validation errors when required to show all errors at once.
func (Errors) MarshalJSON ¶
type ExtError ¶
type ExtError interface {
error
json.Marshaler
// HTTPCode contains info about HTTP code
// that could be sent in the status of the HTTP response.
HTTPCode() int
// ErrMessage contains error message if any.
ErrMessage() string
// ErrDescription returns error detailed info.
ErrDescription() string
// ErrField describes in which field an error has occurred if any.
// For example JSON field in the HTTP request body.
// Typically is used for pointing an invalid field during validation.
ErrField() string
}
ExtError describes extended error. Can be used in the same way as basic error.
func NewBadRequestError ¶
func NewForbiddenError ¶
func NewNotFoundError ¶
func NewUnauthorizedError ¶
type ExtErrors ¶
type ExtErrors interface {
error
json.Marshaler
// Add adds new ExtError to the slice.
Add(...ExtError)
// Errors returns the slice of ExtError for future processing.
Errors() []ExtError
// Len returns current number of added errors.
Len() int
}
func NewExtErrors ¶
func NewExtErrors() ExtErrors
NewExtErrors returns usage ready instance of ExtErrors.
func NewExtErrorsWithCap ¶
NewExtErrorsWithCap returns instance of ExtErrors with specified capacity of underlying slice.
Source Files