Magento2: Creating a preference for category product indexer breaks setup:di:compile

[mbijnsdorp]

Summary

When you create a preference for the category product indexer, code compilation breaks. This is because of the definition of the category product indexer execute method: https://github.com/magento/magento2/blob/2.3.1/app/code/Magento/Catalog/Model/Indexer/Category/Product/Action/Full.php#L155:

public function execute(): self
{
    $this->createTables();
    $this->clearReplicaTables();
    $this->reindex();
    $this->switchTables();
    return $this;
}

Due to the preference, the generated interceptor (Magento already has a plugin defined for the execute method), returns the preferenced class instead of the the Magento indexer, which then doesn't match : self.

Preconditions (*)

1. Magento version: 2.3.1
2. PHP 7.2.12

Steps to reproduce (*)

1. Create a preference for \Magento\Catalog\Model\Indexer\Category\Product\Action\Full in a custom module
2. Run bin/magento setup:di:compile

Expected result (*)

1. Code is compiled

Actual result (*)

1. Fatal error: Declaration of Vendor\Module\Model\Indexer\Category\Product\Action\Full\Interceptor::execute(): Vendor\Module\Model\Indexer\Category\Product\Action\Full must be compatible with Magento\Catalog\Model\Indexer\Category\Product\Action\Full::execute(): Magento\Catalog\Model\Indexer\Category\Product\Action\Full in /var/www/html/generated/code/Vendor/Module/Model/Indexer/Category/Product/Action/Full/Interceptor.php on line 7

/**
 * {@inheritdoc}
 */
public function execute() : \Vendor\Module\Model\Indexer\Category\Product\Action\Full
{
    $pluginInfo = $this->pluginList->getNext($this->subjectType, 'execute');
    if (!$pluginInfo) {
        return parent::execute();
    } else {
        return $this->___callPlugins('execute', func_get_args(), $pluginInfo);
    }
}

[m2-assistant[bot]]

Hi @mbijnsdorp. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• [x] Summary of the issue
• [x] Information on your environment
• [x] Steps to reproduce
• [x] Expected and actual results

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For more details, please, review the Magento Contributor Assistant documentation.

@mbijnsdorp do you confirm that you was able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• [ ] yes
• [ ] no

[orlangur]

Hi @mbijnsdorp, how is that different from https://github.com/magento/magento2/issues/11905?

[mbijnsdorp]

Hi @orlangur, that issue only mentions Magento's code generation not being able to process self in general, which got fixed as the generated code resolves self to a class. However, the following scenario is not covered:

1. Class A contains a public method that returns self and this method has a plugin attached: public function execute(): self
2. Create a preference for class A, class B. This class doesn't extend the execute method.
3. The interceptor that Magento generates now results in public function execute(): B, which is not compatible with the self definition of class A.

[m2-assistant[bot]]

Hi @davidverholen. Thank you for working on this issue.
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[magento-engcom-team]

:white_check_mark: Confirmed by @davidverholen
Thank you for verifying the issue. Based on the provided information internal tickets MC-17251 were created

Issue Available: @davidverholen, _You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself._

[fsw]

@davidverholen as mentioned in #22826 you can test something like this to fix this issue:

diff --git a/lib/internal/Magento/Framework/Interception/Code/Generator/Interceptor.php b/lib/internal/Magento/Framework/Interception/Code/Generator/Interceptor.php
index 9297ca2..acee7c5 100644
--- a/lib/internal/Magento/Framework/Interception/Code/Generator/Interceptor.php
+++ b/lib/internal/Magento/Framework/Interception/Code/Generator/Interceptor.php
@@ -109,7 +109,7 @@ class Interceptor extends \Magento\Framework\Code\Generator\EntityAbstract
             $parameters[] = $this->_getMethodParameterInfo($parameter);
         }

-        $returnTypeValue = $this->getReturnTypeValue($method->getReturnType());
+        $returnTypeValue = $this->getReturnTypeValue($method);
         $methodInfo = [
             'name' => ($method->returnsReference() ? '& ' : '') . $method->getName(),
             'parameters' => $parameters,
@@ -217,16 +217,17 @@ METHOD_BODY
     /**
      * Returns return type
      *
-     * @param mixed $returnType
+     * @param \ReflectionMethod $method
      * @return null|string
      */
-    private function getReturnTypeValue($returnType): ?string
+    private function getReturnTypeValue(\ReflectionMethod $method): ?string
     {
         $returnTypeValue = null;
+        $returnType = $method->getReturnType();
         if ($returnType) {
             $returnTypeValue = ($returnType->allowsNull() ? '?' : '');
             $returnTypeValue .= ($returnType->getName() === 'self')
-                ? $this->getSourceClassName()
+                ? $method->getDeclaringClass()
                 : $returnType->getName();
         }
         return $returnTypeValue;

[m2-assistant[bot]]

Hi @dcabrejas. Thank you for working on this issue.
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  Details

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---

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[magento-engcom-team]

Hi @mbijnsdorp. Thank you for your report.
The issue has been fixed in magento/magento2#23300 by @dcabrejas in 2.3-develop branch
Related commit(s):

• 9c9a3fd069493c9e88406a4b6ee79d41835c8d2a

The fix will be available with the upcoming 2.3.4 release.

[allanpaiste]

Could this really be considered as a fix to the reported issue as it just removed the appearance of the issue where it's still possible to create the same issue whilst using totally valid PHP feature? :/

This way, it's pretty easy to get back to a point where one has to revisit the same issue again in the future unless you ban the usage of 'self' within the code by throwing a meaningful exception (actual change to generator to respect 'self' would be better of course).

Kind of a "door hinge was squeaking, so we removed the door" situation :(

I'd humbly suggest this to be revisited with solution that would be along the lines of what @fsw suggested in his comment.

[dcabrejas]

@allanpaiste Yes, as I said on my PR, this is more of a patch, it fixes the problem. The real issue is still there but the solution is more complicated. That I leave to Magento Team o another contributor who has the time.

[allanpaiste]

@dcabrejas I totally dig the approach of getting the local appearance of the issue quickly dealt with! I was just surprised that the ticket was closed and issue declared as solved.

Created new report that is written in a way that does not allow a "solved" declaration due to not being based on anything that appears in the code but rather on the idea that one can create such a situation by using valid PHP features.

https://github.com/magento/magento2/issues/24443

[dcabrejas]

It was suggested to me by a member of the Magento community engineering team at Meet Magento UK 2019 that's why it got merged. I would argue that merging a patch now solves this issue for a lot of people, which it does. Fixing the issue properly and applying a patch are not contradictory things. They can coexist since both add value. But I have got no horse on this race so I digress. I hope you guys fix the issue though :)

[allanpaiste]

@dcabrejas I'm 100% on board with what you are saying :)

Maybe the new report gets tagged as "wontfix", just wanted to make sure that it's still considered as something that is contained as a problem in the distributed code (as: php feature not used), but that it remains as something that is still perceived as work in progress and as know/open issue :)