fix: update template annotations to remove covariant keyword

[deadLocks21]

Description

This PR addresses PHPStan errors related to template type variance in Doctrine's metadata classes. The errors were occurring because the template type T was declared as covariant but was being used in an invariant position in the getReflectionClass() method.

The Problem

The following errors were reported by PHPStan:

• Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\ODM\MongoDB\Mapping\ClassMetadata::getReflectionClass()
• Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\ORM\Mapping\ClassMetadataInfo::getReflectionClass()
• Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\Persistence\Mapping\ClassMetadata::getReflectionClass()

The Solution

We removed the -covariant modifier from the template type declarations in:

• MongoClassMetadataInfo.stub
• ORM/Mapping/ClassMetadata.stub
• ORM/Mapping/ClassMetadataInfo.stub
• Persistence/Mapping/ClassMetadata.stub

Why This Works

The covariance modifier was inappropriate in this case because:

1. The getReflectionClass() method returns a ReflectionClass<T>
2. This return type must be exactly of the specified type, not a subtype or supertype
3. When a type parameter is used in an invariant position (like a return type), it should not be declared as covariant

Issues

#646

[mroeling]

What is the expected moment to have this merged please? We want to upgrade to php8.4 but this is a blocking issue!

[ondrejmirtes]

@mroeling Please describe what error are you experiencing and why it's blocking you from upgrading to 8.4. It'd be helpful in helping me underseand why this change is needed.

[mroeling]

@mroeling Please describe what error are you experiencing and why it's blocking you from upgrading to 8.4. It'd be helpful in helping me understand why this change is needed.

Ofc, no problem.
Running phpstan on our code raises errors causing phpStan to fail.

Info:
phpstan level 4
Ubuntu 24.04 LTS
php 8.4.11

Line   deploy/app/vendor/phpstan/phpstan-doctrine/stubs/MongoClassMetadataInfo.stub                                                                                            
 ------ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------  
  40     Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\ODM\MongoDB\Mapping\ClassMetadata::getReflectionClass().   
 ------ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------  


 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------  
  Line   deploy/app/vendor/phpstan/phpstan-doctrine/stubs/ORM/Mapping/ClassMetadataInfo.stub                                                                                 
 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------  
  59     Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\ORM\Mapping\ClassMetadataInfo::getReflectionClass().   
 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------  


 ------ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------  
  Line   deploy/app/vendor/phpstan/phpstan-doctrine/stubs/Persistence/Mapping/ClassMetadata.stub                                                                                 
 ------ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------  
  20     Template type T is declared as covariant, but occurs in invariant position in return type of method Doctrine\Persistence\Mapping\ClassMetadata::getReflectionClass().   
 ------ -----------------------------------------------------------------------------------------------------------------------------------------------------------------------  


 [ERROR] Found 3 errors

So basically we are waiting for this change to get into the mainstream so that we can test with php8.4. Using php8.4-fpm there is no issue, but for CLI this is blocking.
For comparison, cli php8.3 does not raise errors (obviously).

[ondrejmirtes]

Please show the path where you're running PHPStan from, the path to bin/phpstan. There is something atypical about your setup. These errors from vendor stubs are usually filtered and not showed.

[mroeling]

We use phing as "executor".

From the root (=phing.dir), the vendor map is in deploy/app/vendor
phpstan is run as deploy/app/vendor/bin/phpstan analyze

    <property name="phpStanBinary"
              value="${phing.dir}/deploy/app/vendor/bin/phpstan"
              override="no"/>
              
                <exec executable="${phpStanBinary}"
                      passthru="true"
                      checkreturn="true"
                      dir="${phing.dir}"
                >
                    <arg value="analyze"/>
                    <arg line="--memory-limit 2G"/>
                    <arg line="--no-progress"/>
                    <arg path="${phing.dir}/deploy/app/include"/>
                    <arg path="${phing.dir}/deploy/app/config"/>
                    <arg path="${phing.dir}/deploy/app/services"/>
                    <arg path="${phing.dir}/tests"/>
                </exec>

The getReflectionClass() functions from these 3 Doctrine classes are called within our codebase, in the deploy/app/include folder

[ondrejmirtes]

That looks okay. Personally I'd try this:

              
                <exec executable="vendor/bin/phpstan"
                      passthru="true"
                      checkreturn="true"
                      dir="${phing.dir}/deploy/app"
                >
                    <arg value="analyze"/>
                    <arg line="--memory-limit 2G"/>
                    <arg line="--no-progress"/>
                    <arg path="include"/>
                    <arg path="config"/>
                    <arg path="services"/>
                    <arg path="tests"/>
                </exec>

Typically people don't run PHPStan with these absolute paths and that might be throwing off the filtering logic.

These bug(s) still need to be fixed, I just want to help you meanwhile.

[mroeling]

These bug(s) still need to be fixed, I just want to help you meanwhile.

Much appreciated! I'll give it a try.