Unit testing Multisite's bootstrap

[jeremyfelt]

This ticket is prodded by the cause of #27866.

We were able to add a few tests for the site and network finding process in #27003 during 3.8 development, but we're still limited by the structure of ms-settings.php pretty severely.

We should be able to test how $_SERVER requests turn into expected $current_site and $current_blog globals.

In an ideal world, we could also harness something in our tests to change the DOMAIN_CURRENT_SITE and PATH_CURRENT_SITE constants on every test to test various situations. If nothing else, we can initiate phpunit with different values.

[jeremyfelt]

So. To start things off at the bottom.

If we move a few things from ms-settings.php to wp-settings.php and remove the need for ms-settings to call any external files, we can technically include ms-settings.php at any time. This could mean unsetting $current_site and $current_blog, changing the $_SERVER request, and then reloading that part of the bootstrap in a unit test to see if we get expected results.

unit-hack.diff does this. ;-/

[nacin]

I don't actually hate this. Nice work. Good to start somewhere.

[jeremyfelt]

Ok. 27884.diff goes all in.

• Introduces wp_network_is_defined(), which applies a network_is_defined filter so that we can specify whether to use DOMAIN_CURRENT_SITE, etc...
• Introduces wp_get_defined_network(), which applies a get_defined_network filter so that we no longer need to rely on constants to predefine the network being loaded.
• Moves the include of ms-load.php, ms-default-constants.php, and sunrise.php to wp-settings.php so that we can include ms-settings.php repeatedly while testing.
• Removes the definition of network constants in the test bootstrap.
• Adds basic multisite bootstrap tests for some easy scenarios.
• Makes use of the new filters while testing so that we can modify the load "constants".

This feels nicer than I expected.

No guarantee on the full MS tests passing, there seems to be a failure of a different type with terms right now. If you run with just the 27884 group, it works fine.

[DrewAPicture]

Hook docs.

[jeremyfelt]

Related #24173 - for testing multisite installed in a subdirectory.

[jeremyfelt]

27884.2.diff pulls back a bit on the previous patch.

• Move all uses of require() to wp-settings.php and leave the include_once and ms_subdomain_constants in ms-settings as these can be called multiple times.
• Add tests for multisite bootstrap
• Remove use of site specific multisite constants in the tests.

[nacin]

In 28910:

Add initial unit tests for multisite's bootstrap.

props jeremyfelt.
fixes #27884.

[danielbachhuber]

fyi - this broke WP-CLI: ​https://github.com/wp-cli/wp-cli/pull/1267

Not really your fault though.

[SergeyBiryukov]

Replying to danielbachhuber:

fyi - this broke WP-CLI: ​https://github.com/wp-cli/wp-cli/pull/1267

Related: #28696.

[jeremyfelt]

As @danielbachhuber mentioned, moving the require() statements out of ms-settings.php and wp-settings.php caused a break with WP-CLI, which closely mirrors the load process here. If the same change was made in WP-CLI, this would break back-compat.

It appears that we can instead use require_once() for ms-load and ms-default-constants and leave this in ms-settings.php without causing issue.

27884.3.diff makes this change. It's likely worth reverting [28910] for the time being to make sure this is the right move.

[SergeyBiryukov]

In 28934:

Move ms-load.php and ms-default-constants.php inclusion back to ms-settings.php to avoid breaking WP-CLI.

Use require_once() to allow for ms-settings.php to be included multiple times while testing.

props jeremyfelt.
see #27884.

[jeremyfelt]

I think we're back to fixed in [28934]

[tellyworth]

I'm getting a PHP warning that I think was created here:

PHP Warning:  Uncaught exception 'PHPUnit_Framework_Error_Notice' with message 'Undefined variable: wpdb' in wordpress-develop/src/wp-includes/ms-settings.php:76

The ! is_subdomain_install() block in ms-settings.php refers to $wpdb which is not in scope when called from _setup_host_request().

Adding $wpdb to the globals in _setup_host_request() fixes it.

[wonderboymusic]

In 29552:

Ensure that $wpdb is imported in Tests_MS::_setup_host_request.

Props tellyworth.
Fixes #27884.

[helen]

Getting a failure:

1) Tests_MS::test_multisite_bootstrap
Failed to assert that define() triggered a deprecated notice

/srv/www/wp-core/develop/tests/phpunit/includes/testcase.php:168
/srv/www/wp-core/develop/tests/phpunit/includes/testcase.php:47
/srv/www/wp-core/develop/tests/phpunit/tests/ms.php:24

[helen]

Actually, going to leave this as fixed for now.