Add ability to define file path of "wp-tests-config.php"

[clarinetlord]

There are several reasons why someone might want to define the location of wp-tests-config.php themselves instead of tests/phpunit/includes/bootstrap.php only checking in two distinct locations. Personally, I would like to define the location outside the project root so I can check the file into my project repositories and keep the develop core as a clean dependency directory. I suggest that the bootstrap check for a constant in the phpunit.xml.dist file, since this file can be copied and modified outside the project to be used by phpunit.

[johnbillion]

Thanks for the ticket, @clarinetlord. This is a sensible request. It would be nice if it could work in the same way as the bootstrap attribute on the phpunit element in phpunit.xml, but I'm not sure if that's possible. Otherwise, a constant makes sense.

[clarinetlord]

Thanks @johnbillion, I think a PHP constant is the best option I can see here. There may be a way to add custom XML attributes to the phpunit.xml file, but it's probably more trouble than it's worth. As a constant, there's also the option to define it other places besides phpunit.xml. Here's a simple patch to bootstrap.php to add this feature.

[johnbillion]

Thanks for the patch. I think the WP_CONFIG_FILE_PATH constant should take precedence over the default location of wp-tests-config.php in case someone wants to do a particularly crazy setup where wp-tests-config.php is in place but they want to override it with WP_CONFIG_FILE_PATH.

[clarinetlord]

That's a good idea. Here's a modified patch that wraps the entire file location check with a check for the existence of that constant first. It seemed cleanest to also set the constant in the default procedure, so it's always defined no matter what. I replaced future variable references with the constant.

[clarinetlord]

Replying to johnbillion:

Hey @johnbillion, any chance we could get this into 5.0?

[kasparsd]

It would be great to get this in for 5.0 especially since #43558 was already merged.

PHPUnit also supports ​defining environment variables but constants appear to be the WordPress way of doing it.

[johnbillion]

39734.patch​ simplifies the patch a little and changes the constant name to WP_TESTS_CONFIG_FILE_PATH.

[johnbillion]

In 43369:

Build/Test Tools: Introduce support for a WP_TESTS_CONFIG_FILE_PATH constant to override the test suite config file location.

This can be used in phpunit.xml:

<php>
	<const name="WP_TESTS_CONFIG_FILE_PATH" value="/path/to/wp-tests-config.php" />
</php>

Props clarinetlord

Fixes #39734

[desrosj]

This was detailed in a dev note: ​https://make.wordpress.org/core/2019/01/23/miscellaneous-developer-focused-changes-in-5-1/