Increase CanValidateDateTimeTest invalid data test coverage

[agchan12]

What?

• Update test cases for the data provider used for the invalid date time tests.

Why?

This change is to ensure Respect\Validation is intentional about the DateTime formats.

For context the ISO 8601 standard says that we shouldn't accept -00:00 (or anything similar) offsets.

I noticed that there was an a change in how CanValidateDateTime.php behaved from v2.2 to v2.3.

Prior to v2.3 date time formats of 2018-01-30T19:04:35-00:00 (note the -00:00) would pass validation. After updating to v2.3 the format is not accepted.

This is because the DateTime::createFromFormat accepts the $value of 2018-01-30T19:04:35-00:00 but internally converts the -00:00 to +00:00

            $formattedDate = DateTime::createFromFormat(
                $format,
                $value,
                new DateTimeZone(date_default_timezone_get())
            );

This in turn causes the validation around $value !== $formattedDate->format($format)) to fail

            if ($formattedDate === false || $value !== $formattedDate->format($format)) {
                return false;
            }

Follow up

Since PHP internally converts the -00:00 to a +00:00, will Respect\Validation ever consider accepting a format of -00:00 (and other offshoots of the -0000 time offsets) 😄 ?