英文:
golang pkg/errors How to print custom wrapped errors?
问题
我的项目包装了一个自定义的错误类型errNotFound，其中嵌入了一个错误。
现在我有一个pkg/errors包，它生成一个打印调用堆栈的错误。但是当我将这个错误内联到errNotFound中时，调用堆栈不会被打印出来。以下是一个示例，我该如何修改它？
简单示例：
package main
import (
"fmt"
stderrors "errors"
"github.com/pkg/errors"
)
func findSomething() error {
return errors.Errorf("something not found")
}
func main() {
err := findSomething()
// 可以打印错误堆栈
exitf("Error1: %+v", err)
fmt.Println()
fmt.Println()
// 无法打印错误堆栈
err = ErrNotFound(err)
exitf("Error2: %+v", err)
}
func exitf(format string, args ...interface{}) {
fmt.Printf(format, args...)
//os.Exit(1)
}
type errNotFound struct{ error }
func ErrNotFound(err error) error {
if err == nil || IsErrNotFound(err) {
return err
}
return errNotFound{err}
}
func IsErrNotFound(err error) bool {
return stderrors.As(err, &errNotFound{})
}
输出结果：
$ go run main
Error1: something not found
main.findSomething
/home/lianxm/github.com/play_error/main.go:11
main.main
/home/lianxm/github.com/play_error/main.go:15
runtime.main
/usr/local/go/src/runtime/proc.go:255
runtime.goexit
/usr/local/go/src/runtime/asm_amd64.s:1581
Error2: something not found
我知道可以通过err = errors.Unwrap(err)获取原始错误，然后打印它，但这意味着我需要在每次打印之前都这样做，这不是很优雅的代码，我真的不想这样做...
这是一个示例项目：https://github.com/lianxmfor/play_error
英文:
My project wraps a custom error type errNotFound, which has an error embedded in it.
Now I have a pkg/errors package that generates an error that prints the call stack. But when I inline this error into errNotFound, the call stack is not printed. Here is a sample, how can I change it?
simple:
package main
import (
"fmt"
stderrors "errors"
"github.com/pkg/errors"
)
func findSomething() error {
return errors.Errorf("something not found")
}
func main() {
err := findSomething()
// can print error stack
exitf("Error1: %+v", err)
fmt.Println()
fmt.Println()
// cannot print error stack
err = ErrNotFound(err)
exitf("Error2: %+v", err)
}
func exitf(format string, args ...interface{}) {
fmt.Printf(format, args...)
//os.Exit(1)
}
type errNotFound struct{ error }
func ErrNotFound(err error) error {
if err == nil || IsErrNotFound(err) {
return err
}
return errNotFound{err}
}
func IsErrNotFound(err error) bool {
return stderrors.As(err, &errNotFound{})
}
output:
$ go run main
Error1: something not found
main.findSomething
/home/lianxm/github.com/play_error/main.go:11
main.main
/home/lianxm/github.com/play_error/main.go:15
runtime.main
/usr/local/go/src/runtime/proc.go:255
runtime.goexit
/usr/local/go/src/runtime/asm_amd64.s:1581
Error2: something not found
I know I can get the original error by err = errors.Unwrap(err) and then print it, but this means that I need to do this every time before printing, which is not very elegant code, and I don't really want to do that...
here is an example project: https://github.com/lianxmfor/play_error
答案1
得分: 1
如果你已经有了堆栈，是否有必要在另一个if语句中放置一个错误？
如果是的话...你可以为errNotFound定义一个方法，如下所示：
func (e errNotFound) Error() string {
return fmt.Printf("NotFound: %+v", e.err)
}
英文:
Is this necessary to put an error inside another if you already have your stack?
If yes... You can define a Method for errNotFound like:
func (e errNotFound) Error() string {
return fmt.Printf("NotFound: %+v", e.err)
}
答案2
得分: 0
你需要使用堆栈注释错误：
func ErrNotFound(err error) error {
if err == nil || IsErrNotFound(err) {
return err
}
return errors.WithStack(errNotFound{err})
}
英文:
you need to annotate the error with stack:
func ErrNotFound(err error) error {
if err == nil || IsErrNotFound(err) {
return err
}
return errors.WithStack(errNotFound{err})
}
答案3
得分: 0
在调用exitf时，你可以使用errors.WithStack来打印堆栈跟踪。
英文:
while calling exitf you can use errors.WithStack to print stack trace.
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