Unable to run \Magento\Downloadable\Test\Unit\Helper\DownloadTest without internet connection / dns resolution

[adrian-martinez-interactiv4]

Preconditions (*)

1. Magento 2.3.2, just created project, no setup:install
2. PHP 7.2.19

Steps to reproduce (*)

1. Create Magento 2.3.2 project
2. Run unit tests (at least \Magento\Downloadable\Test\Unit\Helper\DownloadTest) without internet connection

Expected result (*)

1. Test should pass (image below shows test execution with internet connection):

Actual result (*)

1. Test fails with message (image below shows test execution without internet connection): PHPUnit\Framework\Exception: Warning: get_headers(): php_network_getaddresses: getaddrinfo failed: nodename nor servname provided, or not known in /Users/adrianmartinez/Sites/2.3/magento/vendor/magento/module-downloadable/Helper/Download.php:264.

Extended description

This behaviour cannot be reproduced in 2.2.8, test passes even if there is no internet connection. Comparing code both versions, I've seen this snippet of code has been added in new version of tested class \Magento\Downloadable\Helper\Download:

    public function setResource($resourceFile, $linkType = self::LINK_TYPE_FILE)
    {
        (...)
        
        /**
        * check header for urls
        */
        if ($linkType === self::LINK_TYPE_URL) {
            $headers = array_change_key_case(get_headers($this->_resourceFile, 1), CASE_LOWER);
            if (isset($headers['location'])) {
                $this->_resourceFile  = is_array($headers['location']) ? current($headers['location'])
                    : $headers['location'];
            }
        }
        
        (...)
    }

This new code looks quite risky and not safe, I mean, even if problem is the test not passing, this piece of code has some assumptions that can break execution at any time.

First of all, test relies on a test url: \Magento\Downloadable\Test\Unit\Helper\DownloadTest::URL = 'http://example.com', that may exist or not, or could be down at any time. This means this test could even fail with internet connection if that site is down or DNS servers are not available.

In second place, it tries to extract headers using get_headers php built-in function, and passes the result directly to array_change_key_case, without any kind of check. get_headers may emit a warning if it is not able to get header of supplied url, but even if silenced with @get_headers, execution throws another warning due to get_headers returning false instead of an array, and array_change_key_case complaining about receiving a boolean parameter instead of an array:

1) Magento\Downloadable\Test\Unit\Helper\DownloadTest::testGetFileSizeUrl
PHPUnit\Framework\Exception: Warning: array_change_key_case() expects parameter 1 to be array, boolean given in /Users/adrianmartinez/Sites/2.3/magento/vendor/magento/module-downloadable/Helper/Download.php:264.

I think that piece of code should be refactored through a HeadersResolver (or another more appropriate name), responsible of returning always a consistent return value when requested for some headers (always return an array), and use this new class in \Magento\Downloadable\Helper\Download, so it can be mocked for testing.

[m2-assistant]

Hi @adrian-martinez-interactiv4. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

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

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.3-develop instance - upcoming 2.3.x release

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

@adrian-martinez-interactiv4 do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

[magento-engcom-team]

✅ Confirmed by @engcom-Charlie
Thank you for verifying the issue. Based on the provided information internal tickets MC-17920 were created

Issue Available: @engcom-Charlie, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[aleromano89]

@magento-engcom-team the issue also happens on 2.4-develop

[VladimirZaets]

Hi @adrian-martinez-interactiv4. Thank you for your report.
The issue has been fixed in #26264 by @aleromano89 in 2.4-develop branch
Related commit(s):

• 95fc06f456d933aaaf8ca2b039946dc02d48483d
• b015b65baa6d54dbffd85f11e37d62ca1a28d5da
• 05ecfda9c34698c670ff8fc302632e52fe82f9de

The fix will be available with the upcoming 2.4.0 release.