Forbid use of semi-colon on switch case/default statements

[Crell]

These are almost never used, and are now deprecated in PHP 8.5. Let's go ahead and tell people to never use them in any version.

switch ($val) {
  case 1;  // This works until 8.5, who knew?  But we shouldn't allow it.
    print $val;
  case 2:  // This is the correct way.
    print $val * 2;
}

[jrfnl]

Is it the place of a coding standard to forbid using a deprecated syntax ?

In my opinion, this is not a code style issue, but a language issue and PHP will warn when people use this syntax on PHP versions which don't support it.

If anything, a blanket rule "don't use features which are deprecated for your target PHP version" might as well be added, but historically, the FIG CS standards were only published/approved if they could be automatically enforced and a blanket rule like that will never be fully enforceable via automated tooling.

As a side-note: if you want to forbid the semi-colon as a statement closer for case/default, will you also forbid moving in and out of PHP within a switch ?

switch ($val) {
    case 1 ?><!-- Yes, this will also trigger the deprecation notice as PHP inserts a semi-colon before the PHP close tag. -->
        <div><?= $val ?></div>
        <?php break ?>
    <?php case 2 ?>
        <div><?= $val * 2 ?></div>
        <?php break;
}