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);

[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 👍

[themasch]

Sorry to dig up old discussions here, but I just run into a similar problem with the 8.4 upgrade and explicit nullables.
The ExplicitNullableParamTypeRector is gates behing PHP_84, but the resulting code is actually valid since PHP 7.1.
There where attempts to address this, but it was decided that it should remain that way:
See for example this: rectorphp/rector-src#5848
And this discussion: rectorphp/rector-src#5724 (review)

For me the minPhpVersion currently attempts to do two things at once: For some rules, it definies the actual PHP version where the result becomes valid PHP code, e.g. AddTypeToConstRector is gates behint PHP_83 because before that its not valid.
For ExplicitNullableParamTypeRector on the other hand the minPhpVersion describes the PHP version where the old code is no longer "good" (e.g. deprecated).

So currently theres not way to "upgrade early", e.g. get 8.4 compliant code that also works fine with 8.3, except setting $rectorConfig->phpVersion(PhpVersion::PHP_84) and hoping it doesnt attempt to generate code that actually requires 8.4 (dropping parantheses on constructors, property hooks, etc).

Has the projects view on this "upgrade-early" approach changed?

[samsonasik]

@themasch see answered question regarding ExplicitNullableParamTypeRector #8823 (comment)

[themasch]

@samsonasik thanks for the quick response, I was not aware that implicit nullables behaved differently regarding that optional-paramter-before-required-paramter rule.
That indeed makes it harder to generally apply that rector to code pre 8.4.
Makes sense now, thanks!