Fixed undefined index referring

[a-menshchikov]

Type: bugfix
Issue: Resolves #816
Breaking change: no

[kylekatarnls]

Thank you @a-menshchikov did you find when/why (with which analyzed code) $parameters[$argumentPosition] is undefined?

[a-menshchikov]

@kylekatarnls error rising on the following code:

<?php

declare(strict_types=1);

namespace App\Controller\Api\admin\Settings\Language;

use App\Controller\Api\AbstractApiController;
use App\Entity\Language;
use App\Entity\User\Role;
use FOS\RestBundle\Controller\Annotations as Rest;
use FOS\RestBundle\View\View;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\IsGranted;

final class Activate extends AbstractApiController
{
    /**
     * @Rest\Patch("/settings/language/{id}/activate", name="language.activate")
     * @Rest\View(serializerGroups={"admin:language:status"})
     *
     * @IsGranted(Role::ADMIN)
     */
    public function __invoke(Language $language): View
    {
        $language->setActive(true);

        $this->flush($language);

        return $this->success($language);
    }
}

---

Full error output (with xdebug enabled):

PHP Notice:  Undefined offset: 0 in /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Rule/AbstractLocalVariable.php on line 271
PHP Stack trace:
PHP   1. {main}() /usr/src/app/vendor/phpmd/phpmd/src/bin/phpmd:0
PHP   2. PHPMD\TextUI\Command::main($args = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/bin/phpmd:61
PHP   3. PHPMD\TextUI\Command->run($opts = *uninitialized*, $ruleSetFactory = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/TextUI/Command.php:148
PHP   4. PHPMD\PHPMD->processFiles($inputPath = *uninitialized*, $ruleSets = *uninitialized*, $renderers = *uninitialized*, $ruleSetFactory = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/TextUI/Command.php:103
PHP   5. PHPMD\Parser->parse($report = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/PHPMD.php:192
PHP   6. PDepend\Engine->analyze() /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php:95
PHP   7. PHPMD\Parser->close() /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Engine.php:357
PHP   8. PDepend\Source\AST\ASTNamespace->accept($visitor = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php:148
PHP   9. PHPMD\Parser->visitNamespace($namespace = *uninitialized*) /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Source/AST/ASTNamespace.php:320
PHP  10. PDepend\Source\AST\ASTClass->accept($visitor = *uninitialized*) /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Source/ASTVisitor/AbstractASTVisitor.php:214
PHP  11. PHPMD\Parser->visitClass($node = *uninitialized*) /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Source/AST/ASTClass.php:196
PHP  12. PHPMD\Parser->visitClass($class = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php:188
PHP  13. PDepend\Source\AST\ASTMethod->accept($visitor = *uninitialized*) /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Source/ASTVisitor/AbstractASTVisitor.php:110
PHP  14. PHPMD\Parser->visitMethod($node = *uninitialized*) /usr/src/app/vendor/pdepend/pdepend/src/main/php/PDepend/Source/AST/ASTMethod.php:219
PHP  15. PHPMD\Parser->apply($node = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php:234
PHP  16. PHPMD\RuleSet->apply($node = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php:259
PHP  17. PHPMD\Rule\CleanCode\UndefinedVariable->apply($node = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/RuleSet.php:255
PHP  18. PHPMD\Rule\CleanCode\UndefinedVariable->isPassedByReference($variable = *uninitialized*) /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Rule/CleanCode/UndefinedVariable.php:78
PHP Fatal error:  Uncaught Error: Call to a member function isPassedByReference() on null in /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Rule/AbstractLocalVariable.php:271
Stack trace:
#0 /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Rule/CleanCode/UndefinedVariable.php(78): PHPMD\Rule\AbstractLocalVariable->isPassedByReference()
#1 /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/RuleSet.php(255): PHPMD\Rule\CleanCode\UndefinedVariable->apply()
#2 /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php(259): PHPMD\RuleSet->apply()
#3 /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Parser.php(234): PHPMD\Parser->apply()
#4 /usr/src/app/vendor/pdepend/pdepend/src/main/p in /usr/src/app/vendor/phpmd/phpmd/src/main/php/PHPMD/Rule/AbstractLocalVariable.php on line 271

---

Maybe it will be useful: $functionName in AbstractLocalVariable::isPassedByReference() is equal "flush" and UndefinedVariable check $language variable on error.

[tvbeek]

@a-menshchikov thanks for the PR (and the issue) do you have the possibility to add a test to the PR? With that we have a verification that it is fixed and we don't destroy it in another release.

I assign this PR to you, but feel free to say if you need help creating the tests.

[a-menshchikov]

@tvbeek I think I need help with tests because at the moment I have no idea how to create it`s.

[kylekatarnls]

No problem. I will use the example you provided to add it.

[kylekatarnls]

I just tried the same code chunk but get no error. I also tried with PDepend 2.7.1. I think we should merge this and #821, release the patch 2.9.1 to fix the error then take the time to understand why and how it happen to fix it properly.

[kylekatarnls]

I could reproduce the bug. I'll add the tests in a second PR.

[kylekatarnls]

For the record: the error happen if there is more arguments in call than in definition:

function foo($a, $b) {}

foo($v1, $v2, $v3);

Or if the definition of the function/method couldn't not be found. I both situation, it would be fine IMO to consider by default the variable is not passed by reference.

[kylekatarnls]

Erratum: the actual trigger is the method name "flush". PHPMD tried to match the arguments with the flush() function of PHP to check arguments passed by reference. So it's a problem to detect $this-> and understand that flush is a method and not a function.

So it could lead to argument wrongly detected as passed by reference.

[kylekatarnls]

Funny fact: PHPStorm seems to do the same mistake as it underlines $undefined in $this->Xpreg_match('', '', $undefined) but not in $this->preg_match('', '', $undefined) .

[a-menshchikov]

@kylekatarnls flush method used from trait that imported in parent class:

    protected function flush(?object $entity = null): void
    {
        $this->getManager($entity)->flush();
    }