WP Core Tests vs PHP 8.1

Introduction for the live streamed mob programming session of July 30th, 2021, with as the topic: Modernizing the WP Core test suite to allow the tests to run on PHP 8.1.

Slides set forth the problem outline and solution direction applied in the patch which was reviewed during the remainder of the session.

Missed it ? The recording is available as video on demand at https://www.youtube.com/watch?v=SAtiKaUwLU4

Transcript

1. WP Core Tests vs PHP 8.1 Juliette Reinders Folmer Tweet about it: @jrf_nl
2. Current Situation ▪ Composer "phpunit/phpunit": "^7.5" ▪ Composer lock file Continuous Integration: ▪ PHP 5.6, 7.0: Use PHPUnit 5.7 Phar ▪ PHP 7.1 – 7.4: Use PHPUnit 7.5 Phar ▪ PHP 8.0: Use Composer install with –ignore-platform-reqs Copied in PHPUnit 9.x MockObject files
3. The Problem With the Current Setup Testing locally against different PHP versions PHP 8.1 Maintenance burden
4. PHPUnit Support v Compatible with: 10 PHP >= 8.0 (expected end of 2021) 9 PHP >= 7.3 8 PHP >= 7.2 7 PHP 7.1, 7.2, 7.3 [EOL] 6 PHP 7.0, 7.1, 7.2 [EOL] 5 PHP 5.6, 7.0, 7.1 [EOL] Seemann
5. Making Test Suites PHPUnit Cross-version Compatible Renamed/split assertion and expectation methods void return type for fixture methods (PHPUnit >= 8.0) Configuration file format change (PHPUnit >= 9.3)
6. PHPUnit vs PHP PHPUnit / PHP 5.6 7.0 7.1 7.2 7.3 7.4 8.0 8.1 5.x 6.x 7.x 8.x 8.6+ ? 9.x 9.3+ 9.6+ ? 10.x void 8.5+
7. What Happened Last Year ? (PHP 8.0) Phar Version constraint 5.x PHPUnit version constraints Mocking Code Coverage Composer Version constraint 7.x --ignore-platform-reqs in CI Copied in files from PHPUnit 9.x Not available on PHP 8.0
8. PHP 8.1 vs PHPUnit 7.x  Config file  PHPUnit 7.x + PHPUnit 7.x dependencies incompatible with PHP 8.1 (and won't be fixed anymore)
9. Constraints and Wishes » Supporting PHP 5.6 + 7.0 still required » Plugin tests often extend WP integration test suite » Supporting both PHPUnit PHAR + Composer install preferred » Make running tests locally against different PHP versions easier for contributors
10. WP native solution PHPUnit Polyfills Symfony Bridge Options
11. PHPUnit Polyfills What you get: ▪ Polyfills via traits for all new assertions and expectations in PHPUnit ▪ Helper to work round removal of assertAttribute*() methods ▪ An cross-version compatible abstract base TestCase (to get round void) which includes all polyfills ▪ A cross-version compatible TestListenerImplementation Sponsored by:
12. Action Plan ❑Remove composer.lock file ❑Use PHPUnit 9.x assertion and expectation methods ❑Solve void for fixtures ❑Remove old work-arounds ❑Enable testing against PHP 8.1 in CI ❑Fix any and all PHP 8.1 incompatibilities
13. Follow Along ▪ Remove composer.lock https://core.trac.wordpress.org/ticket/47381 Patch: https://github.com/WordPress/wordpress-develop/pull/1511 ▪ Make test suite compatible with PHPUnit 8.x + 9.x https://core.trac.wordpress.org/ticket/46149 Patches not pulled yet: https://github.com/jrfnl/wordpress-develop- official/tree/WIP/all-stacked-in-the-right-order ▪ PHP 8.1 fixes https://core.trac.wordpress.org/ticket/53635
14. Open Questions ▪ What to do about the Speedtrap listener package ? ▪ How to handle the stdClass / __invoke() warning ? ▪ Update the Core Test running and contributing docs
15. Further Reading ▪ The Grumpy Programmer's Guide to Testing PHP Applications https://grumpy-learning.com/ ▪ Your Mocks Won't Save You! https://24daysindecember.net/2020/12/08/your-mocks-wont-save-you/ ▪ My Top 10 PHPUnit Tips & Tricks https://speakerdeck.com/jrf/my-top-10-phpunit-tips-and-tricks-e6ea54ce- 2515-4ea9-aacf-9bf7ab3b3141 ▪ PHPUnit Documentation https://phpunit.readthedocs.io/ ▪ Path Coverage in PHPUnit https://doug.codes/php-code-coverage
16. Tooling ▪ PHPUnit Polyfills https://packagist.org/packages/yoast/phpunit-polyfills ▪ WP Test Utils https://packagist.org/packages/yoast/wp-test-utils
17. Thanks! @jrf_nl @jrfnl Any questions ? Slides: https://speakerdeck.com/jrf