package stub import ( "errors" "strconv" ) var ( ErrCheck = errors.New("one or more arguments did not match") ) // UniqueError is an error that only equivalates to another [UniqueError] with // the same magic value. type UniqueError uintptr func (e UniqueError) Error() string { return "unique error " + strconv.FormatUint(uint64(e), 10) + " injected by the test suite" } func (e UniqueError) Is(target error) bool { u, ok := errors.AsType[UniqueError](target) return ok && e == u }