api/errdefs/is.go

package errdefs

type causer interface {
	Cause() error
}

func getImplementer(err error) error {
	switch e := err.(type) {
	case
		ErrNotFound,
		ErrInvalidParameter,
		ErrConflict,
		ErrUnauthorized,
		ErrUnavailable,
		ErrForbidden,
		ErrSystem,
		ErrNotModified,
		ErrNotImplemented,
		ErrUnknown:
		return e
	case causer:
		return getImplementer(e.Cause())
	default:
		return err
	}
}

// IsNotFound returns if the passed in error is a ErrNotFound
func IsNotFound(err error) bool {
	_, ok := getImplementer(err).(ErrNotFound)
	return ok
}

// IsInvalidParameter returns if the passed in error is an ErrInvalidParameter
func IsInvalidParameter(err error) bool {
	_, ok := getImplementer(err).(ErrInvalidParameter)
	return ok
}

// IsConflict returns if the passed in error is a ErrConflict
func IsConflict(err error) bool {
	_, ok := getImplementer(err).(ErrConflict)
	return ok
}

// IsUnauthorized returns if the the passed in error is an ErrUnauthorized
func IsUnauthorized(err error) bool {
	_, ok := getImplementer(err).(ErrUnauthorized)
	return ok
}

// IsUnavailable returns if the passed in error is an ErrUnavailable
func IsUnavailable(err error) bool {
	_, ok := getImplementer(err).(ErrUnavailable)
	return ok
}

// IsForbidden returns if the passed in error is a ErrForbidden
func IsForbidden(err error) bool {
	_, ok := getImplementer(err).(ErrForbidden)
	return ok
}

// IsSystem returns if the passed in error is a ErrSystem
func IsSystem(err error) bool {
	_, ok := getImplementer(err).(ErrSystem)
	return ok
}

// IsNotModified returns if the passed in error is a NotModified error
func IsNotModified(err error) bool {
	_, ok := getImplementer(err).(ErrNotModified)
	return ok
}

// IsNotImplemented returns if the passed in error is a ErrNotImplemented
func IsNotImplemented(err error) bool {
	_, ok := getImplementer(err).(ErrNotImplemented)
	return ok
}

// IsUnknown returns if the passed in error is an ErrUnknown
func IsUnknown(err error) bool {
	_, ok := getImplementer(err).(ErrUnknown)
	return ok
}