Make module compatible with Magento 2.4

[mbijnsdorp]

• add @var to unit test (phpstan threw errors)
• update composer dependencies according to Magento 2.4
• update unit test to make it compatible

Due to the phpunit change, it's no longer backwards compatible with earlier versions of Magento. Let me know If you want to have additional changes or so because of it.

[hostep]

Thanks @mbijnsdorp!

I was planning on investigating compatibility with Magento 2.4.0 later this week, this PR will help me with that!
I'll try to check it out in the coming days and get back to you!

[hostep]

Thanks for the PR @mbijnsdorp: it mostly looks fine, but I'll add some changes:

• /** @var MockObject $productCollectionMock */ instead of /** @var \PHPUnit\Framework\MockObject\MockObject $productCollectionMock */
• I'll update the PHPCompatibility tests, so it ignores the Tests in this module, since they are now no longer compatible with PHP 7.0 due to the added void return type, which is only supported in PHP 7.1 and higher

I'll create some extra commits to fix these things, then do a final review and do some manual tests. When everything looks fine, I'll tag a new release.

Thanks again!

[hostep]

@mbijnsdorp: unfortunately I found a regression in 2.4.0 with this module which needs additional research: #11

So I won't be tagging a new version until we've figured out a solution for that issue. I hope it won't take long to figure that out! 🙂

[hostep]

#11 is fixed. Released v1.2.0

Thanks again!