perf: enable PHPUnit 12 execution ordering and GC control in test configs

[lbajsarowicz]

Summary

Enables three PHPUnit 12 configuration attributes across integration and unit test configs to improve test execution time and memory stability:

• executionOrder="depends" (integration) — ensures @depends / #[Depends] chains execute in the correct order. Uses depends only (not depends,duration) to preserve the explicit "Memory Usage Tests run first" guarantee documented in the suite definition.
• executionOrder="depends,duration" (unit) — respects dependency chains and schedules faster tests first. Safe here because there are no ordering constraints between unit test suites.
• controlGarbageCollector="true" (both) — lets PHPUnit trigger gc_collect_cycles() periodically during long runs, preventing gradual memory bloat that causes slowdowns and OOM kills in CI. Thresholds: 50 tests for integration (heavier fixture graphs), 200 for unit (lightweight).

Problem

1. Test ordering: The current configs use PHPUnit's default discovery order. 22 integration test files use @depends/#[Depends] (e.g. ConfigurableTest.php), but without executionOrder="depends", PHPUnit does not guarantee dependency chains execute correctly — leading to intermittent failures.

2. Memory growth: Long integration test runs accumulate cyclic references from fixture graphs, DI containers, and service objects. Without periodic GC, PHP's refcount-based memory management cannot reclaim these, causing memory usage to grow monotonically until the process is killed or becomes swap-bound.

Changes

File	Attribute	Value	Why
dev/tests/integration/phpunit.xml.dist	executionOrder	depends	Respect @depends without reordering suites (preserves Memory Usage Tests priority)
dev/tests/integration/phpunit.xml.dist	controlGarbageCollector	true	Periodic GC during long integration runs
dev/tests/integration/phpunit.xml.dist	numberOfTestsBeforeGarbageCollection	50	Integration tests are heavy; GC every 50 tests
dev/tests/unit/phpunit.xml.dist	executionOrder	depends,duration	Respect dependencies + run fast tests first
dev/tests/unit/phpunit.xml.dist	controlGarbageCollector	true	Periodic GC during full suite runs
dev/tests/unit/phpunit.xml.dist	numberOfTestsBeforeGarbageCollection	200	Unit tests are lighter; less frequent GC needed

Test plan

• php vendor/bin/phpunit -c dev/tests/unit/phpunit.xml.dist --list-suites — config accepted by PHPUnit 12.5.14
• php vendor/bin/phpunit -c dev/tests/unit/phpunit.xml.dist --no-coverage app/code/Magento/Catalog/Test/Unit/ — 2632 tests pass
• All attributes validate against PHPUnit 12.5 XSD schema
• CI integration tests pass with new config

References

• PHPUnit 12.5 configuration docs
• PHPUnit 12.5 CLI options

⭐ Support my work

Do you like the fix? Remember to react with "👍🏻" to get it merged faster,
Then Sponsor me on Github so I can spend more time on fixing issues like this one.

Learn more at https://github.com/sponsors/lbajsarowicz

Resolved issues:

1. resolves [Issue] perf: enable PHPUnit 12 execution ordering and GC control in test configs #40768: perf: enable PHPUnit 12 execution ordering and GC control in test configs

[m2-assistant]

Hi @lbajsarowicz. Thank you for your contribution!
Here are some useful tips on how you can test your changes using Magento test environment.
❗ Automated tests can be triggered manually with an appropriate comment:

• @magento run all tests - run or re-run all required tests against the PR changes
• @magento run <test-build(s)> - run or re-run specific test build(s)
  For example: @magento run Unit Tests

<test-build(s)> is a comma-separated list of build names.

Allowed build names are:

1. Database Compare
2. Functional Tests CE
3. Functional Tests EE
4. Functional Tests B2B
5. Integration Tests
6. Magento Health Index
7. Sample Data Tests CE
8. Sample Data Tests EE
9. Sample Data Tests B2B
10. Static Tests
11. Unit Tests
12. WebAPI Tests
13. Semantic Version Checker

You can find more information about the builds here
ℹ️ Run only required test builds during development. Run all test builds before sending your pull request for review.

---

For more details, review the Code Contributions documentation.
Join Magento Community Engineering Slack and ask your questions in #github channel.

[lbajsarowicz]

@magento run all tests

[engcom-Dash]

@magento create issue