Allow use factories and OM for creating objects with variadic arguments in constructor

[adrian-martinez-interactiv4]

Description (*)

Currently, if you have a class using a variadic argument in constructor, it is not possible to use generated factories or OM to instantiate it. Having this as example, there is no way to instantiate it using CustomObjectPoolFactory generated class:

/**
 * Demo class CustomObjectPool, accepting variable number of arguments, all of them of CustomObject type
 */
class CustomObjectPool
{
    /**
     * @var CustomObject[]
     */
    private $customObjects;

    /**
     * CustomObjectPool constructor.
     * @param CustomObject[] ...$customObjects
     */
    public function __construct(CustomObject ...$customObjects)
    {
        $this->customObjects = $customObjects;
    }
}

This is a test snippet, that fails with a type error exception:

<?php

use Magento\Framework\App\Area;

require __DIR__ . '/app/bootstrap.php';

/**
 * Demo class CustomObject
 */
class CustomObject
{
}

/**
 * Demo class CustomObjectPool, accepting variable number of arguments, all of them of CustomObject type
 */
class CustomObjectPool
{
    /**
     * @var CustomObject[]
     */
    private $customObjects;

    /**
     * CustomObjectPool constructor.
     * @param CustomObject[] ...$customObjects
     */
    public function __construct(CustomObject ...$customObjects)
    {
        $this->customObjects = $customObjects;
    }
}

/**
 * Class TestApp
 */
class TestApp extends \Magento\Framework\App\Http implements \Magento\Framework\AppInterface
{
    public function launch()
    {
        $this->_state->setAreaCode(Area::AREA_GLOBAL);
        $this->_objectManager->configure($this->_configLoader->load(Area::AREA_GLOBAL));

        // Used this way instead of constructor for convenience, not needed for ilustrative example
        $customObjectPoolFactory = $this->_objectManager->get(CustomObjectPoolFactory::class);
        // Line below throws type error exception
        $customObjectPool = $customObjectPoolFactory->create();
        // This line below also throws type error exception
        $customObjectPool = $customObjectPoolFactory->create(
            [
                'customObjects' => [
                    new CustomObject(),
                    new CustomObject(),
                ]
            ]
        );

        return $this->_response;
    }

    public function catchException(\Magento\Framework\App\Bootstrap $bootstrap, \Exception $exception)
    {
        var_dump($exception->getMessage());
        var_dump($exception->getTraceAsString());
        exit();
    }
}

$bootstrap = \Magento\Framework\App\Bootstrap::create(BP, $_SERVER);

/** @var \Magento\Framework\App\Http $app */
$app = $bootstrap->createApplication(TestApp::class);
$bootstrap->run($app);

With provided changes, variadic arguments are supported, including building without arguments:

$customObjectPool = $customObjectPoolFactory->create();

Or defining them as an array:

$customObjectPool = $customObjectPoolFactory->create(
            [
                'customObjects' => [
                    new CustomObject(),
                    new CustomObject(),
                ]
            ]
        );

Or defining a single one in a simple way:

$customObjectPool = $customObjectPoolFactory->create(
            [
                'customObjects' => new CustomObject()
            ]
        );

Or injecting them from di.xml config.

Fixed Issues (if relevant)

None AFAIK, improvement

Manual testing scenarios (*)

Use provided snippet.

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[m2-assistant]

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[buskamuza]

Nice improvement. Did you have a chance to check if it would be possible to specify arguments in di.xml as well?

[adrian-martinez-interactiv4]

@buskamuza I tested it here: https://github.com/magento/magento2/pull/24556/files#diff-3fe7b0651b076e3b1c628181bb34eca0R298, but having a second look at it, it may not work with real defined di.xml parameters, I'll review it.

[adrian-martinez-interactiv4]

@buskamuza After reviewed, it seems it should work.

About Database Compare build failing, there are no build reports available.

[magento-engcom-team]

Hi @ihor-sviziev, thank you for the review.
ENGCOM-5927 has been created to process this Pull Request
✳️ @ihor-sviziev, could you please add one of the following labels to the Pull Request?

Label	Description
Auto-Tests: Covered	All changes in Pull Request is covered by auto-tests
Auto-Tests: Not Covered	Changes in Pull Request requires coverage by auto-tests
Auto-Tests: Not Required	Changes in Pull Request does not require coverage by auto-tests

[ihor-sviziev]

@magento run Database Compare build

[engcom-Bravo]

✔️ QA Passed

[m2-assistant]

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