goark/errs パッケージ v1.2.1 をリリースした

package main

import (
    "errors"
    "fmt"
    "io"
    "os"

    "github.com/goark/errs"
)

func generateMultiError() error {
    return errs.New("error with multiple causes", errs.WithCause(errors.Join(os.ErrInvalid, io.EOF)))
}

func main() {
    err := generateMultiError()
    fmt.Println(errors.Is(err, io.EOF)) // true
}

func main() {
    err := generateMultiError()
    fmt.Printf("%+v\n",  err)
}

$ go run sample4.go | jq .
{
  "Type": "*errs.Error",
  "Err": {
    "Type": "*errors.errorString",
    "Msg": "error with multiple causes"
  },
  "Context": {
    "function": "main.generateMultiError"
  },
  "Cause": {
    "Type": "*errors.joinError",
    "Msg": "invalid argument\nEOF",
    "Cause": [
      {
        "Type": "*errors.errorString",
        "Msg": "invalid argument"
      },
      {
        "Type": "*errors.errorString",
        "Msg": "EOF"
      }
    ]
  }
}

// Deprecated: should not be used
func Cause(err error) error {
    for err != nil {
        unwraped := errors.Unwrap(err)
        if unwraped == nil {
            return err
        }
        err = unwraped
    }
    return err
}

func Unwraps(err error) []error {
    if err != nil {
        if es, ok := err.(interface {
            Unwrap() []error
        }); ok {
            return es.Unwrap()
        }
    }
    e := errors.Unwrap(err)
    if e != nil {
        return []error{e}
    }
    return nil
}