func TestInvalidGob(t *testing.T) { cases := []struct { bytes []byte want string }{ {[]byte{}, "Date.UnmarshalBinary: no data"}, {[]byte{1, 2, 3}, "Date.UnmarshalBinary: invalid length"}, } for _, c := range cases { var ignored date.Date err := ignored.GobDecode(c.bytes) if err == nil || err.Error() != c.want { t.Errorf("InvalidGobDecode(%v) == %v, want %v", c.bytes, err, c.want) } err = ignored.UnmarshalBinary(c.bytes) if err == nil || err.Error() != c.want { t.Errorf("InvalidUnmarshalBinary(%v) == %v, want %v", c.bytes, err, c.want) } } }