udeServer/internal/apierr/apierr.go

// Package apierr provides HTTP-aware errors and a default error handler.
package apierr

import (
	"errors"
	"fmt"
	"net/http"
)

// Error carries the HTTP status code that should be returned to the client.
type Error struct {
	Status int
	Msg    string
}

func (e *Error) Error() string {
	return e.Msg
}

// New returns an error with the given HTTP status code.
func New(status int, msg string) error {
	return &Error{Status: status, Msg: msg}
}

// BadRequest returns a 400 error.
func BadRequest(format string, args ...any) error {
	return New(http.StatusBadRequest, fmt.Sprintf(format, args...))
}

// NotFound returns a 404 error.
func NotFound(kind string, id int64) error {
	return New(http.StatusNotFound, fmt.Sprintf("%s id=%d not found", kind, id))
}

// Status resolves the HTTP status code of err. Errors wrapping unrecovered
// failures (database, network, ...) must have no apierr.Error in their
// chain, hence they resolve to 500.
func Status(err error) int {
	var e *Error
	if errors.As(err, &e) {
		return e.Status
	}

	return http.StatusInternalServerError
}