Improve plugin compatibility with HealthCheck - PageCache

inc/Engine/HealthCheck/PageCache.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace WP_Rocket\Engine\HealthCheck;
+
+use WP_Rocket\Event_Management\Subscriber_Interface;
+
+class PageCache implements Subscriber_Interface {
+	/**
+	 * Returns an array of events that this subscriber wants to listen to.
+	 *
+	 * @return array
+	 */
+	public static function get_subscribed_events() {
+		return [
+			'http_headers_useragent' => [ 'page_cache_useragent', 10, 2 ],
+		];
+	}
+
+	/**
+	 * Pass plugin header to skip test "mandatory cookie".
+	 *
+	 * @param string $user_agent WordPress user agent string.
+	 * @param string $url        The request URL.
+	 * @return string
+	 */
+	public function page_cache_useragent( $user_agent, $url = null ) {
+		$uri = sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ?? '' ) );
+		if (
+			strpos( $uri, 'wp-site-health' ) !== false &&
+			strpos( $uri, 'page-cache' ) !== false
+		) {
+			$user_agent = 'WP Rocket';
+		}
+
+		return $user_agent;
+	}
+}

inc/Engine/HealthCheck/ServiceProvider.php

@@ -16,6 +16,7 @@ class ServiceProvider extends AbstractServiceProvider {
 	 */
 	protected $provides = [
 		'health_check',
+		'health_check_page_cache',
 		'action_scheduler_check',
 	];
 
@@ -38,6 +39,7 @@ public function provides( string $id ): bool {
 	public function register(): void {
 		$this->getContainer()->addShared( 'health_check', HealthCheck::class )
 			->addArgument( 'options' );
+		$this->getContainer()->addShared( 'health_check_page_cache', PageCache::class );
 		$this->getContainer()->addShared( 'action_scheduler_check', ActionSchedulerCheck::class );
 	}
 }

inc/Plugin.php

@@ -389,6 +389,7 @@ private function init_common_subscribers() {
 			'media_fonts_frontend_subscriber',
 			'media_fonts_admin_subscriber',
 			'media_fonts_clean_subscriber',
+			'health_check_page_cache',
 		];
 
 		$host_type = HostResolver::get_host_service();

tests/Fixtures/inc/Engine/HealthCheck/PageCache/userAgent.php

@@ -0,0 +1,19 @@
+<?php
+
+return [
+	'null' => [
+		'request_uri' => null,
+		'user_agent_default' => 'WordPress',
+		'user_agent_expected' => 'WordPress',
+	],
+	'default' => [
+		'request_uri' => '/wp-json/wp-site-health/v1/tests/https-status?_locale=user',
+		'user_agent_default' => 'WordPress',
+		'user_agent_expected' => 'WordPress',
+	],
+	'plugin' => [
+		'request_uri' => '/wp-json/wp-site-health/v1/tests/page-cache?_locale=user',
+		'user_agent_default' => 'WP Rocket',
+		'user_agent_expected' => 'WP Rocket',
+	],
+];

tests/Unit/inc/Engine/HealthCheck/PageCache/userAgent.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace WP_Rocket\Tests\Unit\inc\Engine\HealthCheck\PageCache;
+
+use Brain\Monkey\Functions;
+use WP_Rocket\Engine\HealthCheck\PageCache;
+use WP_Rocket\Tests\Unit\TestCase;
+
+/**
+ * @covers \WP_Rocket\Engine\HealthCheck\PageCache::page_cache_useragent
+ *
+ * @group  zzz
+ */
+class Test_UserAgent extends TestCase {
+	private $health;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->health = new PageCache();
+
+		Functions\when( 'sanitize_text_field' )->alias(
+			function ( $value ) {
+				return $value;
+			}
+		);
+
+		Functions\when( 'wp_unslash' )->alias(
+			function ( $value ) {
+				return stripslashes( $value );
+			}
+		);
+	}
+
+	/**
+	 * @dataProvider configTestData
+	 */
+	public function testShouldReturnExpected( $request_uri, $user_agent_default, $user_agent_expected ) {
+		$_SERVER['REQUEST_URI'] = $request_uri;
+
+		$user_agent = $this->health->page_cache_useragent( $user_agent_default );
+		$this->assertSame( $user_agent_expected, $user_agent );
+	}
+}