Omit page caching and object caching tests for Site Health if on WP>=6.1

[milindmore22]

Feature Description

New description from @westonruter: The Site Health tests for page caching and object caching from the AMP plugin have been incorporated into WordPress core as of 6.1. See WordPress/performance#220 (Core-56041) and WordPress/performance#35 (Core-56040). At the very least these tests can be disabled in WP 6.1+. But I think it would be better to just remove them entirely.

Original description

We got a support topic where the user is getting a site health a warning for cache plugin, although he is using a cache plugin (Litespeed cache) because LiteSpeed uses a different header it's not able to detect it.

The Litespeed author suggested that we use a filter so that other vendors can pass their headers so it will fix warnings for their plugins.

Acceptance Criteria

No response

Implementation Brief

No response

QA Testing Instructions

No response

Demo

No response

Changelog Entry

No response

[westonruter]

Actually, since page caching detection is now part of Site Health in WordPress core, I think we can just remove our check entirely now, right?

There is a filter that caching plugins can use to add recognition of their own headers, as noted in the support topic.

[westonruter]

For the impending release, we could just disable the tests by default. Then in the next release we could remove them entirely, if this would make it easier to get the release out the door.

[thelovekesh]

We are also using page cache tests internally.

amp-wp/src/Admin/OptionsMenu.php

Line 250 in a2d8418

$page_cache_detail = $this->site_health->get_page_cache_detail( true );

amp-wp/assets/src/settings-page/settings-footer.js

Line 120 in a2d8418

{HAS_PAGE_CACHING &&

[westonruter]

Presumably these should be using what core has now for WP>=6.1.

[thelovekesh]

I need to dig in more but seems like it could be tricky to determine due to the visibility of methods.

https://github.com/WordPress/wordpress-develop/blob/ce342f1a33051dcafdb47132f8e07d0597f49124/src/wp-admin/includes/class-wp-site-health.php#L3458

[westonruter]

Ah yes. Well, in that case, we can just add a condition to only include the following tests if WP<6.1:

amp-wp/src/Admin/SiteHealth.php

Lines 183 to 186 in a2d8418

	$tests['direct']['amp_persistent_object_cache'] = [
	'label' => esc_html__( 'Persistent object cache', 'amp' ),
	'test' => [ $this, 'persistent_object_cache' ],
	];

amp-wp/src/Admin/SiteHealth.php

Lines 220 to 227 in a2d8418

	if ( $this->supports_async_rest_tests( $tests ) ) {
	$tests['async'][ self::TEST_PAGE_CACHING ] = [
	'label' => esc_html__( 'Page caching', 'amp' ),
	'test' => rest_url( self::REST_API_NAMESPACE . self::REST_API_PAGE_CACHE_ENDPOINT ),
	'has_rest' => true,
	'async_direct_test' => [ $this, 'page_cache' ],
	];
	}

The latter essentially already has such a test, but for WP 5.6.

[pavanpatil1]

QA Passed ✅

Cross-verified the issue and the page caching and object caching test notices are not visible. Now, it is only visible if WP version is less than 6.1.

Before fix	After fix