Send Add/Remove activities when changing a post's sticky status

.github/changelog/add-featured-collection-activities

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Send Add/Remove activities when changing a post's sticky status to improve interoperability with the featured collection.

includes/scheduler/class-actor.php

@@ -154,7 +154,7 @@ public static function schedule_profile_update( $user_id ) {
 	}
 
 	/**
-	 * Detect sticky posts update.
+	 * Send a profile update when a post's sticky status changes.
 	 *
 	 * @param int $post_id The post ID.
 	 */

includes/scheduler/class-post.php

@@ -7,7 +7,11 @@
 
 namespace Activitypub\Scheduler;
 
+use Activitypub\Activity\Activity;
+use Activitypub\Collection\Actors;
+
 use function Activitypub\add_to_outbox;
+use function Activitypub\get_post_id;
 use function Activitypub\get_wp_object_state;
 use function Activitypub\is_post_disabled;
 
@@ -29,6 +33,19 @@ public static function init() {
 		\add_action( 'add_attachment', array( self::class, 'transition_attachment_status' ) );
 		\add_action( 'edit_attachment', array( self::class, 'transition_attachment_status' ) );
 		\add_action( 'delete_attachment', array( self::class, 'transition_attachment_status' ) );
+
+		/*
+		 * Sticky post transitions (featured collection).
+		 *
+		 * Note: These hooks run in addition to the legacy sticky hooks in
+		 * Actor scheduler, which send an Update activity when a post becomes
+		 * sticky or is unstuck. This means a sticky/unsticky event will cause both:
+		 * - an Add/Remove activity for the Actor's featured collection (below), and
+		 * - an Update activity (from Actor scheduler).
+		 * The Update activity is kept for backwards compatibility.
+		 */
+		\add_action( 'post_stuck', array( self::class, 'schedule_featured_add' ) );
+		\add_action( 'post_unstuck', array( self::class, 'schedule_featured_remove' ) );
 	}
 
 	/**
@@ -166,4 +183,63 @@ public static function transition_attachment_status( $post_id ) {
 			add_to_outbox( $post, $type, $post->post_author );
 		}
 	}
+
+	/**
+	 * Schedule an Add activity when a post is added to the featured collection.
+	 *
+	 * @param int $post_id The post ID.
+	 */
+	public static function schedule_featured_add( $post_id ) {
+		self::schedule_featured_update( $post_id, 'Add' );
+	}
+
+	/**
+	 * Schedule a Remove activity when a post is removed from the featured collection.
+	 *
+	 * @param int $post_id The post ID.
+	 */
+	public static function schedule_featured_remove( $post_id ) {
+		self::schedule_featured_update( $post_id, 'Remove' );
+	}
+
+	/**
+	 * Schedule an Add or Remove activity for the featured collection.
+	 *
+	 * When a post's sticky status changes, this sends an Add or Remove activity
+	 * to notify followers about the change to the actor's featured collection.
+	 *
+	 * @see https://github.com/Automattic/wordpress-activitypub/issues/2795
+	 *
+	 * @param int    $post_id       The post ID.
+	 * @param string $activity_type The activity type ('Add' or 'Remove').
+	 */
+	private static function schedule_featured_update( $post_id, $activity_type ) {
+		if ( \defined( 'WP_IMPORTING' ) && WP_IMPORTING ) {
+			return;
+		}
+
+		$post = \get_post( $post_id );
+
+		if ( ! $post ) {
+			return;
+		}
+
+		if ( is_post_disabled( $post ) ) {
+			return;
+		}
+
+		$actor = Actors::get_by_id( $post->post_author );
+
+		if ( ! $actor || \is_wp_error( $actor ) ) {
+			return;
+		}
+
+		$activity = new Activity();
+		$activity->set_type( $activity_type );
+		$activity->set_actor( $actor->get_id() );
+		$activity->set_object( get_post_id( $post->ID ) );
+		$activity->set_target( $actor->get_featured() );
+
+		add_to_outbox( $activity, null, $post->post_author );
+	}
 }

tests/phpunit/tests/includes/scheduler/class-test-actor.php

@@ -306,33 +306,6 @@ public function test_actor_profile_update_sets_updated_attribute() {
 		$this->assertEqualsWithDelta( strtotime( $post->post_modified ), strtotime( $activity['updated'] ), 2, 'Updated attribute does not match post modified date.' );
 	}
 
-	/**
-	 * Test that sticky posts are detected.
-	 *
-	 * @covers ::sticky_post_update
-	 */
-	public function test_sticky_post_update() {
-		$user_id = self::factory()->user->create( array( 'role' => 'author' ) );
-
-		$last_item = $this->get_latest_outbox_item();
-
-		$this->assertNull( $last_item );
-
-		$post_id = self::factory()->post->create( array( 'post_author' => $user_id ) );
-		\stick_post( $post_id );
-
-		$last_item_stick = $this->get_latest_outbox_item();
-
-		$this->assertNotNull( $last_item_stick );
-
-		\unstick_post( $post_id );
-
-		$last_item_unstick = $this->get_latest_outbox_item();
-
-		$this->assertNotEquals( $last_item_stick->ID, $last_item_unstick->ID );
-		$this->assertEquals( $last_item_stick->post_author, $last_item_unstick->post_author );
-	}
-
 	/**
 	 * Test that user deletion creates a Delete activity.
 	 *

tests/phpunit/tests/includes/scheduler/class-test-post.php

@@ -7,6 +7,7 @@
 
 namespace Activitypub\Tests\Scheduler;
 
+use Activitypub\Collection\Actors;
 use Activitypub\Scheduler\Post;
 
 /**
@@ -195,4 +196,96 @@ public function test_no_activity_scheduled( $args ) {
 
 		$this->assertNull( $this->get_latest_outbox_item( $activitypub_id ) );
 	}
+
+	/**
+	 * Test that sticking a post creates an Add activity for the featured collection.
+	 *
+	 * @covers ::schedule_featured_add
+	 * @covers ::schedule_featured_update
+	 */
+	public function test_sticky_post_creates_add_activity() {
+		$user_id = self::factory()->user->create( array( 'role' => 'author' ) );
+		$actor   = Actors::get_by_id( $user_id );
+
+		$post_id        = self::factory()->post->create( array( 'post_author' => $user_id ) );
+		$activitypub_id = \Activitypub\get_post_id( $post_id );
+
+		\stick_post( $post_id );
+
+		// Query for the Add activity by object ID and activity type.
+		$outbox_items = \get_posts(
+			array(
+				'post_type'   => 'ap_outbox',
+				'post_status' => 'pending',
+				'meta_query'  => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+					array(
+						'key'   => '_activitypub_object_id',
+						'value' => $activitypub_id,
+					),
+					array(
+						'key'   => '_activitypub_activity_type',
+						'value' => 'Add',
+					),
+				),
+			)
+		);
+
+		$this->assertCount( 1, $outbox_items );
+
+		$last_item = $outbox_items[0];
+
+		// Verify the activity content.
+		$activity = \json_decode( $last_item->post_content, true );
+		$this->assertEquals( 'Add', $activity['type'] );
+		$this->assertEquals( $actor->get_id(), $activity['actor'] );
+		$this->assertEquals( $activitypub_id, $activity['object'] );
+		$this->assertEquals( $actor->get_featured(), $activity['target'] );
+	}
+
+	/**
+	 * Test that unsticking a post creates a Remove activity for the featured collection.
+	 *
+	 * @covers ::schedule_featured_remove
+	 * @covers ::schedule_featured_update
+	 */
+	public function test_unsticky_post_creates_remove_activity() {
+		$user_id = self::factory()->user->create( array( 'role' => 'author' ) );
+		$actor   = Actors::get_by_id( $user_id );
+
+		$post_id        = self::factory()->post->create( array( 'post_author' => $user_id ) );
+		$activitypub_id = \Activitypub\get_post_id( $post_id );
+
+		// First stick, then unstick.
+		\stick_post( $post_id );
+		\unstick_post( $post_id );
+
+		// Query for the Remove activity by object ID and activity type.
+		$outbox_items = \get_posts(
+			array(
+				'post_type'   => 'ap_outbox',
+				'post_status' => 'pending',
+				'meta_query'  => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+					array(
+						'key'   => '_activitypub_object_id',
+						'value' => $activitypub_id,
+					),
+					array(
+						'key'   => '_activitypub_activity_type',
+						'value' => 'Remove',
+					),
+				),
+			)
+		);
+
+		$this->assertCount( 1, $outbox_items );
+
+		$last_item = $outbox_items[0];
+
+		// Verify the activity content.
+		$activity = \json_decode( $last_item->post_content, true );
+		$this->assertEquals( 'Remove', $activity['type'] );
+		$this->assertEquals( $actor->get_id(), $activity['actor'] );
+		$this->assertEquals( $activitypub_id, $activity['object'] );
+		$this->assertEquals( $actor->get_featured(), $activity['target'] );
+	}
 }