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
   

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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
   

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3. The Problem With the Current Setup
   Testing locally
   against different
   PHP versions
   PHP 8.1 Maintenance burden
   

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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
   

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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)
   

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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+
   

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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
   

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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)
   

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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
   

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10. WP native
    solution
    PHPUnit
    Polyfills
    Symfony
    Bridge
    Options
    

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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:
    

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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
    

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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
    

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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
    

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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
    

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16. Tooling
    ▪ PHPUnit Polyfills
    https://packagist.org/packages/yoast/phpunit-polyfills
    ▪ WP Test Utils
    https://packagist.org/packages/yoast/wp-test-utils
    

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17. Thanks!
    @jrf_nl @jrfnl
    Any
    questions ?
    Slides: https://speakerdeck.com/jrf
    

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