フューチャー製OSSのreguerrに入門しつつ、エラーハンドリングしてPRあげてみた

package example

import (
	"gitlab.com/future-architect/reguerr"
)

var (
	// No message arguments
	PermissionDeniedErr = reguerr.New("1001", "permission denied").Build()

	// One message arguments
	UpdateConflictErr = reguerr.New("1002", "other user updated: key=%s").Build()

	// Message arguments with label
	InvalidInputParameterErr = reguerr.New("1003", "invalid input parameter: %v").
		Label(0,"payload", map[string]interface{}{}).
		Build()
)

// generated by reguerr; DO NOT EDIT
package example

import (
        "errors"
        "github.com/future-architect/reguerr"
)

// NewPermissionDeniedErr is the error indicating [1001] permission denied: $err.
func NewPermissionDeniedErr(err error) *reguerr.ReguError {
        return PermissionDeniedErr.WithError(err)
}

// IsPermissionDeniedErr indicates if the passed in error is from the error with code [1001].
func IsPermissionDeniedErr(err error) bool {
        var cerr *reguerr.ReguError
        if as := errors.As(err, &cerr); as {
                if cerr.Code() == PermissionDeniedErr.Code() {
                        return true
                }
        }
        return false
}

// NewUpdateConflictErr is the error indicating [1002] other user updated: key=%s: $err.
func NewUpdateConflictErr(err error, arg1 interface{}) *reguerr.ReguError {
        return UpdateConflictErr.WithError(err).WithArgs(arg1)
}

// IsUpdateConflictErr indicates if the passed in error is from the error with code [1002].
func IsUpdateConflictErr(err error) bool {
        var cerr *reguerr.ReguError
        if as := errors.As(err, &cerr); as {
                if cerr.Code() == UpdateConflictErr.Code() {
                        return true
                }
        }
        return false
}

// NewInvalidInputParameterErr is the error indicating [1003] invalid input parameter: %v: $err.
func NewInvalidInputParameterErr(err error, payload map[string]interface{}) *reguerr.ReguError {
        return InvalidInputParameterErr.WithError(err).WithArgs(payload)
}

// IsInvalidInputParameterErr indicates if the passed in error is from the error with code [1003].
func IsInvalidInputParameterErr(err error) bool {
        var cerr *reguerr.ReguError
        if as := errors.As(err, &cerr); as {
                if cerr.Code() == InvalidInputParameterErr.Code() {
                        return true
                }
        }
        return false
}

func NewLevel(s string) (Level, error) {
	switch strings.ToLower(s) {
	case strings.ToLower(Trace.String()):
		return Trace, nil
	case strings.ToLower(Debug.String()):
		return Debug, nil
	case strings.ToLower(Info.String()):
		return Info, nil
	case strings.ToLower(Warn.String()):
		return Warn, nil
	case strings.ToLower(Error.String()):
		return Error, nil
	case strings.ToLower(Fatal.String()):
		return Fatal, nil
	default:
		return Trace, errors.New("unknown error level")  //ここが47行目
	}
}

var opts []gen.Option
if errLevel != "" {
	level, err := reguerr.NewLevel(errLevel + "Level")  //ここが71行目
	if err != nil{
		return err
	}
	opts = append(opts, gen.DefaultErrorLevel(level))
}
if statusCode != -1 {
	opts = append(opts, gen.DefaultStatusCode(statusCode))
}

fmt.Printf("[USER]strings.ToLower(s)=%v\n", strings.ToLower(s))
fmt.Printf("[USER]strings.ToLower(Info.String())=%v\n", strings.ToLower(Info.String()))

// level, err := reguerr.NewLevel(errLevel + "Level")
level, err := reguerr.NewLevel(errLevel)