bnkamalesh/errors

package errors

import "errors"

// Unwrap calls the Go builtin errors.UnUnwrap
func Unwrap(err error) error {
    return errors.Unwrap(err)
}

// Is calls the Go builtin errors.Is
func Is(err, target error) bool {
    return errors.Is(err, target)
}

// As calls the Go builtin errors.As
func As(err error, target interface{}) bool {
    return errors.As(err, target)
}

func Join(errs ...error) error {
    n := len(errs)
    if n == 0 {
        return nil
    }

    e := &joinError{
        errs: make([]error, 0, n),
    }
    for _, err := range errs {
        if err == nil {
            continue
        }
        e.errs = append(e.errs, err)
    }

    n = len(e.errs)
    if n == 0 {
        return nil
    }

    return e
}

type joinError struct {
    errs []error
}

func (e *joinError) Error() string {
    var b []byte
    for i, err := range e.errs {
        if i > 0 {
            b = append(b, '\n')
        }
        b = append(b, err.Error()...)
    }
    return string(b)
}

func (e *joinError) Unwrap() []error {
    return e.errs
}