Enhanced error handling based on new features introduced in Go 1.13

werror.go

package werror

import (
	"fmt"
)

type Error struct {
	Err error // the underlying error
	Str string
}

func Wrap(err error) *Error {
	return &Error{
		Err: err,
	}
}

func (e *Error) SetError(err error) *Error {
	e.Str = err.Error()
	return e
}

func (e *Error) SetErrorf(format string, a ...interface{}) *Error {
	e.Str = fmt.Sprintf(format, a...)
	return e
}

// Error implements the error interface.
func (e *Error) Error() string { return e.Str }

// Unwrap follows the Unwrap convention introduced in Go 1.13,
// See https://blog.golang.org/go1.13-errors
func (e *Error) Unwrap() error { return e.Err }