first-commit

modules/util/error.go

@@ -0,0 +1,97 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package util
+
+import (
+	"errors"
+	"fmt"
+)
+
+// Common Errors forming the base of our error system
+//
+// Many Errors returned by Gitea can be tested against these errors using "errors.Is".
+var (
+	ErrInvalidArgument  = errors.New("invalid argument")        // also implies HTTP 400
+	ErrPermissionDenied = errors.New("permission denied")       // also implies HTTP 403
+	ErrNotExist         = errors.New("resource does not exist") // also implies HTTP 404
+	ErrAlreadyExist     = errors.New("resource already exists") // also implies HTTP 409
+
+	// ErrUnprocessableContent implies HTTP 422, the syntax of the request content is correct,
+	// but the server is unable to process the contained instructions
+	ErrUnprocessableContent = errors.New("unprocessable content")
+)
+
+// errorWrapper provides a simple wrapper for a wrapped error where the wrapped error message plays no part in the error message
+// Especially useful for "untyped" errors created with "errors.New(…)" that can be classified as 'invalid argument', 'permission denied', 'exists already', or 'does not exist'
+type errorWrapper struct {
+	Message string
+	Err     error
+}
+
+// Error returns the message
+func (w errorWrapper) Error() string {
+	return w.Message
+}
+
+// Unwrap returns the underlying error
+func (w errorWrapper) Unwrap() error {
+	return w.Err
+}
+
+type LocaleWrapper struct {
+	err    error
+	TrKey  string
+	TrArgs []any
+}
+
+// Error returns the message
+func (w LocaleWrapper) Error() string {
+	return w.err.Error()
+}
+
+// Unwrap returns the underlying error
+func (w LocaleWrapper) Unwrap() error {
+	return w.err
+}
+
+// ErrorWrap returns an error that formats as the given text but unwraps as the provided error
+func ErrorWrap(unwrap error, message string, args ...any) error {
+	if len(args) == 0 {
+		return errorWrapper{Message: message, Err: unwrap}
+	}
+	return errorWrapper{Message: fmt.Sprintf(message, args...), Err: unwrap}
+}
+
+// NewInvalidArgumentErrorf returns an error that formats as the given text but unwraps as an ErrInvalidArgument
+func NewInvalidArgumentErrorf(message string, args ...any) error {
+	return ErrorWrap(ErrInvalidArgument, message, args...)
+}
+
+// NewPermissionDeniedErrorf returns an error that formats as the given text but unwraps as an ErrPermissionDenied
+func NewPermissionDeniedErrorf(message string, args ...any) error {
+	return ErrorWrap(ErrPermissionDenied, message, args...)
+}
+
+// NewAlreadyExistErrorf returns an error that formats as the given text but unwraps as an ErrAlreadyExist
+func NewAlreadyExistErrorf(message string, args ...any) error {
+	return ErrorWrap(ErrAlreadyExist, message, args...)
+}
+
+// NewNotExistErrorf returns an error that formats as the given text but unwraps as an ErrNotExist
+func NewNotExistErrorf(message string, args ...any) error {
+	return ErrorWrap(ErrNotExist, message, args...)
+}
+
+// ErrorWrapLocale wraps an err with a translation key and arguments
+func ErrorWrapLocale(err error, trKey string, trArgs ...any) error {
+	return LocaleWrapper{err: err, TrKey: trKey, TrArgs: trArgs}
+}
+
+func ErrorAsLocale(err error) *LocaleWrapper {
+	var e LocaleWrapper
+	if errors.As(err, &e) {
+		return &e
+	}
+	return nil
+}