Run PHP unit tests in different versions of PHP

[spacedmonkey]

Feature Description

Run PHP unit tests in different versions of PHP in CI.

[mxbclang]

Tagging in @felixarntz for further discussion.

[merkys7]

We could make Github workflow to test using multiple PHP versions, like the following example: https://github.com/WordPress/rollback-update-failure/blob/main/.github/workflows/wp-phpunit.yml

If that's the case, could I assign this issue to myself?

[mxbclang]

@merkys7 I'd like to get @felixarntz's input on this one before we proceed, and he's out of the office for the next few weeks. Stand by. :)

[mukeshpanchal27]

We should set a similar Github workflow that we have for WordPress/wordpress-develop https://github.com/WordPress/wordpress-develop/blob/trunk/.github/workflows/phpunit-tests.yml because we have to add our module code/tests on WordPress core so we face some issues when we move our changes here to the core.

[felixarntz]

@merkys7 @mukeshpanchal27 @bethanylang I definitely support expanding our GitHub workflow to test using additional PHP versions. However I have some specific feedback:

• We should not test for every supported PHP version as that would take way too long and not really help that much. I would instead choose 3 very different PHP versions and limit testing to those, for example the latest (for now 8.1), the oldest supported (for now 5.6) and something in between (for now e.g. 7.4).
• We should expand and follow the setup in our existing GitHub action rather than creating something from scratch, most importantly we should keep using @wordpress/env which ensures we maintain our very easy-to-configure setup and don't have to manually maintain a Docker configuration etc.
• Looking at the @wordpress/env documentation linked above, it looks like we can set a WP_ENV_PHP_VERSION environment variable to force the PHP version to a specific version. So I think we can modify our existing https://github.com/WordPress/performance/blob/trunk/.github/workflows/php-test.yml to include a matrix of PHP versions and then use the above environment variable to set up @wordpress/env correctly.

Let me know your thoughts.

[mukeshpanchal27]

@felixarntz Sorry for the delay. I agree with you. I will explore that document.

[mukeshpanchal27]

@felixarntz I have submitted PR for this issue but different PHP version is not support when we set custom phpVersion config value. Check WordPress/gutenberg#29323 for more information.