How to upgrade php version keeping backward compatibility ?

[beeyev]

I am currently using PHP 7.0 and would like to update to PHP 7.1.
my configuration is quite simple:

    $rectorConfig->phpVersion(PhpVersion::PHP_70);
    $rectorConfig->import(LevelSetList::UP_TO_PHP_71);

When I run rector, it makes changes which are not backward compatible with php 7.0, for example it adds public visibility prefixes to the constants.

Is there any way to tell Rector to update the code to php 7.1 but keep it compatible with php 7.0?

[TomasVotruba]

Hi,

the 2nd line changes PHP version to PHP 7.1:

$rectorConfig->phpVersion(PhpVersion::PHP_70);
$rectorConfig->import(LevelSetList::UP_TO_PHP_71);

Change the order:

$rectorConfig->import(LevelSetList::UP_TO_PHP_71);
$rectorConfig->phpVersion(PhpVersion::PHP_70);

[TomasVotruba]

I see. What would you recommend to do here?

[Offspring2099]

Hi,

I think it's correct to have Php4ConstructorRector included in /config/set/php70.php, because that was the first PHP version when the older style constructor was deemed deprecated.

But isn't __constructor style constructor valid syntax in PHP5, then I would think, NO_PHP4_CONSTRUCTOR should be set to some PHP5 version?

Then one can set $rectorConfig->import(LevelSetList::UP_TO_PHP_70); to get their code compliant with PHP70, while setting $rectorConfig->phpVersion(PhpVersion::PHP_56); to keep their code still compliant with PHP56 and Php4ConstructorRector rule would be applied and the rector'ed code should still work in PHP56 and PHP70 will not generate e_deprecated

EDIT:
https://wiki.php.net/rfc/remove_php4_constructors
Perhaps NO_PHP4_CONSTRUCTOR could be PHP_52 (lowest php version I see in rector consts), but can go as low as php5.0.

[TomasVotruba]

Hi, the upgrade sets follow "upgrade-early" approach. Otherwise, project would be in a very bad shape even in PHP 9.
So the rule should be in the set it was the first introduced 👍

[Offspring2099]

Sorry if I'm completely misunderstanding this, I'm not disputing that the set is wrong. The 70 set is correct to include Php4ConstructorRector rule.

It seems that Php4ConstructorRector rule is restricted, not to upgrade, unless the current php version is 70. Which does seem to contradict the "upgrade-early" approach.
In the case of this config:

$rectorConfig->import(LevelSetList::UP_TO_PHP_70);  <--- want my code to be php70 ready
$rectorConfig->phpVersion(PhpVersion::PHP_56);     <---- but I'm still on php56

Wouldn't one want the rule applied in php5 (that would be earlier than 7)

[TomasVotruba]

It seems that Php4ConstructorRector rule is restricted, not to upgrade, unless the current php version is 70. Which does seem to contradict the "upgrade-early" approach.

That's what should be fixed then 👍