68 lines
1.9 KiB
Go
68 lines
1.9 KiB
Go
|
// Copyright 2020 the Pinniped contributors. All Rights Reserved.
|
||
|
|
// SPDX-License-Identifier: Apache-2.0
|
||
|
|
|
||
|
|
// Package httperr contains some helpers for nicer error handling in http.Handler implementations.
|
||
|
|
package httperr
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"net/http"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Responder represents an error that can emit a useful HTTP error response to an http.ResponseWriter.
|
||
|
|
type Responder interface {
|
||
|
|
error
|
||
|
|
Respond(http.ResponseWriter)
|
||
|
|
}
|
||
|
|
|
||
|
|
// New returns a Responder that emits the given HTTP status code and message.
|
||
|
|
func New(code int, msg string) error {
|
||
|
|
return httpErr{code: code, msg: msg}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Newf returns a Responder that emits the given HTTP status code and fmt.Sprintf formatted message.
|
||
|
|
func Newf(code int, format string, args ...interface{}) error {
|
||
|
|
return httpErr{code: code, msg: fmt.Sprintf(format, args...)}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Wrap returns a Responder that emits the given HTTP status code and message, and also wraps an internal error.
|
||
|
|
func Wrap(code int, msg string, cause error) error {
|
||
|
|
return httpErr{code: code, msg: msg, cause: cause}
|
||
|
|
}
|
||
|
|
|
||
|
|
type httpErr struct {
|
||
|
|
code int
|
||
|
|
msg string
|
||
|
|
cause error
|
||
|
|
}
|
||
|
|
|
||
|
|
func (e httpErr) Error() string {
|
||
|
|
if e.cause != nil {
|
||
|
|
return fmt.Sprintf("%s: %v", e.msg, e.cause)
|
||
|
|
}
|
||
|
|
return e.msg
|
||
|
|
}
|
||
|
|
|
||
|
|
func (e httpErr) Respond(w http.ResponseWriter) {
|
||
|
|
// http.Error is important here because it prevents content sniffing by forcing text/plain.
|
||
|
|
http.Error(w, http.StatusText(e.code)+": "+e.msg, e.code)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (e httpErr) Unwrap() error {
|
||
|
|
return e.cause
|
||
|
|
}
|
||
|
|
|
||
|
|
// HandlerFunc is like http.HandlerFunc, but with a function signature that allows easier error handling.
|
||
|
|
type HandlerFunc func(http.ResponseWriter, *http.Request) error
|
||
|
|
|
||
|
|
func (f HandlerFunc) ServeHTTP(w http.ResponseWriter, r *http.Request) {
|
||
|
|
switch err := f(w, r).(type) {
|
||
|
|
case nil:
|
||
|
|
return
|
||
|
|
case Responder:
|
||
|
|
err.Respond(w)
|
||
|
|
default:
|
||
|
|
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
|
||
|
|
}
|
||
|
|
}
|