Auth0 Go SDK Error Type

error.go

package management

type ErrorType int

const (
	UnknownError ErrorType = iota

	CannotSetUsernameForConnectionError

	PasswordStrengthError

	UsernameAlreadyInUse

	ConnectionDoesNotExist
)

var toErrorType = map[string]ErrorType{
	"Cannot set username for connection without requires_username": CannotSetUsernameForConnectionError,
	"PasswordStrengthError: Password is too weak":                  PasswordStrengthError,
	"The username provided is in use already.":                     UsernameAlreadyInUse,
	"The connection does not exist.":                               ConnectionDoesNotExist,
}

type Error interface {
	Status() int
	error
}

type managementError struct {
	StatusCode int    `json:"statusCode"`
	Err        string `json:"error"`
	Message    string `json:"message"`
	errType    string `json:"-"`
}

func newError(r io.Reader) error {
	m := &managementError{}
	err := json.NewDecoder(r).Decode(m)
	if err != nil {
		return err
	}
	m.errType = toErrorType[m.Message] // if not found, defaults to zero value: UnknownError
	return m
}

func (m *managementError) Error() string {
	return fmt.Sprintf("%d %s: %s", m.StatusCode, m.Err, m.Message)
}

func (m *managementError) Status() int {
	return m.StatusCode
}

func (m *managementError) Type() ErrorType {
	return m.errType
}

usage.go

if err := api.User.Create(u); err != nil {
    switch err.(management.Error).Type() {
    case management.UsernameAlreadyInUse:
        // handle email already exists
    case management.PasswordStrengthError:
        // handle password strength error
    }
}

Drew inspiration from this gist.