Add PHP unit tests for theme starter content

[westonruter]

Needing tests:

• \WP_Customize_Manager::import_theme_starter_content()
• \get_theme_starter_content()
• The clearing of the fresh_site flag.

See #38114, #38533.

[welcher]

I'm writing up some tests for \get_theme_starter_content and noticed that it is possible to do this add_theme_support( 'starter-content' ) which causes a PHP invalid foreach error.

I am not sure how common that would be but there is no check in get_theme_starter_content to ensure that $theme_support is an array. I've attached a patch with tests to address this and introduce a new test file for the method.

[westonruter]

@welcher yeah, you're right. If $config is anything other than an array then it should be overridden to be an empty array.

[welcher]

@westonruter the patch I added addresses the issue - should that get committed before the tests are completed? I can also add a separate patch for just the tests if that makes sense as well.

[westonruter]

@welcher you can include that fix with your unity tests patch.

[westonruter]

@welcher are you going to flesh out the unit tests? Note that some key fixes were done as part of #38541.

[welcher]

Replying to westonruter:

@welcher are you going to flesh out the unit tests? Note that some key fixes were done as part of #38541.

@westonruter I am working on updating my tests for reflect the key changes.

[welcher]

Patch with tests for get_theme_starter_content()

[welcher]

@westonruter I've added some tests for the default content that is generated. The patch also contains the fix if for not passing the second parameter to add_theme_support.

I'm hoping to keep working on the tests for the other items in this ticket but time is in short supply lately so if there is anyone that wants to jump in and help that would be awesome.

[westonruter]

In 39276:

Customize: Add unit tests for importing theme starter content.

Props welcher, westonruter.
See #38114, #38533, #38615.
Fixes #38540.