Add more unit tests namespaces to FeatureFlag extension

INFO

This document represents an architecture decision record (ADR) and has been mirrored from the ADR section in our Shopware 6 repository. You can find the original version here

Context

The Shopware\Core\Test\PHPUnit\Extension\FeatureFlag\Subscriber\TestPreparationStartedSubscriber only allows the Shopware\Tests\Unit namespace to be considered when enabling the major feature in the unit tests suite.

Decision

To be able to unit test the upcoming major feature in other plugins we will enable the possibility to add other namespaces to the Shopware\Core\Test\PHPUnit\Extension\FeatureFlag\Subscriber\TestPreparationStartedSubscriber.

We'll add a static method called addNamespace() method to the Shopware\Core\Test\PHPUnit\Extension\FeatureFlag\FeatureFlagExtension and by this we are able to add other namespaces to the allowlist of the namespaces to be considered when enabling the major flags in the unit test suite.

This can be useful for plugins that wants to enable the major flags in their unit tests suite.

Therefore, add the extension to the extension list in the phpunit.xml:

<extensions>
    ...
    <bootstrap class="Shopware\Core\Test\PHPUnit\Extension\FeatureFlag\FeatureFlagExtension"/>
</extensions>

And register your test namespace in your test bootstrap file:

FeatureFlagExtension::addTestNamespace('Your\\Unit\\Tests\\Namespace\\');

For example, in the Commercial plugin, we added the following code to the tests/TestBootstrap.php file:

FeatureFlagExtension::addTestNamespace('Shopware\\Commercial\\Tests\\Unit\\');

Consequences

If your namespace will be added via the FeatureFlagExtension::addNamespace() method, the major flags will be enabled by default in your unit tests suite, and you have to explicitly disable the feature you don't want to be executed with the upcoming major flag turned on. If you want to know the decision why all feature flags are activated by default, please read this ADR.