From 65240a5cf2e23e2bc96792fb4f846223205f7337 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 16:46:20 -0300
Subject: [PATCH 01/13] feat(content-distribution): partial payload

---
 includes/class-content-distribution.php       | 76 +++++++++++++++++--
 .../class-incoming-post.php                   | 31 +++++++-
 .../class-outgoing-post.php                   | 37 +++++++++
 .../test-incoming-post.php                    | 47 ++++++++++++
 .../test-outgoing-post.php                    | 12 +++
 5 files changed, 192 insertions(+), 11 deletions(-)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index 6075878..36bd4e4 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -30,7 +30,7 @@ class Content_Distribution {
 	 *
 	 * @var array Post IDs to update.
 	 */
-	private static $queued_post_updates = [];
+	private static $queued_distributions = [];
 
 	/**
 	 * Initialize this class and register hooks
@@ -77,22 +77,53 @@ public static function register_data_event_actions() {
 		Data_Events::register_action( 'network_incoming_post_inserted' );
 	}
 
+	/**
+	 * Queue post distribution to run on PHP shutdown.
+	 *
+	 * @param int         $post_id       The post ID.
+	 * @param null|string $post_data_key The post data key to update.
+	 *                                   Default is null (entire post payload).
+	 *
+	 * @return void
+	 */
+	public static function queue_post_distribution( $post_id, $post_data_key = null ) {
+		// Bail if the post is already queued for a full update.
+		if ( isset( self::$queued_distributions[ $post_id ] ) && self::$queued_distributions[ $post_id ] === true ) {
+			return;
+		}
+
+		// Queue for a full post update.
+		if ( empty( $post_data_key ) ) {
+			self::$queued_distributions[ $post_id ] = true;
+			return;
+		}
+
+		// Queue for a partial update.
+		if ( ! isset( self::$queued_distributions[ $post_id ] ) ) {
+			self::$queued_distributions[ $post_id ] = [];
+		}
+		self::$queued_distributions[ $post_id ][] = $post_data_key;
+	}
+
 	/**
 	 * Distribute queued posts.
 	 */
 	public static function distribute_queued_posts() {
-		if ( empty( self::$queued_post_updates ) ) {
+		if ( empty( self::$queued_distributions ) ) {
 			return;
 		}
-		$post_ids = array_unique( self::$queued_post_updates );
-		foreach ( $post_ids as $post_id ) {
+		foreach ( self::$queued_distributions as $post_id => $post_data_keys ) {
 			$post = get_post( $post_id );
 			if ( ! $post ) {
 				continue;
 			}
-			self::distribute_post( $post );
+			if ( is_array( $post_data_keys ) ) {
+				self::distribute_post_partial( $post, array_unique( $post_data_keys ) );
+			} else {
+				self::distribute_post( $post );
+			}
 		}
-		self::$queued_post_updates = [];
+		self::$queued_distributions = [];
 	}
 
 	/**
@@ -170,7 +201,7 @@ public static function handle_postmeta_update( $meta_id, $object_id, $meta_key )
 		) {
 			return;
 		}
-		self::$queued_post_updates[] = $object_id;
+		self::queue_post_distribution( $post->ID, 'post_meta' );
 	}
 
 	/**
@@ -191,7 +222,7 @@ public static function handle_post_updated( $post ) {
 		if ( ! self::is_post_distributed( $post ) ) {
 			return;
 		}
-		self::$queued_post_updates[] = $post->ID;
+		self::queue_post_distribution( $post->ID );
 	}
 
 	/**
@@ -388,4 +419,33 @@ public static function distribute_post( $post, $status_on_create = 'draft' ) {
 			update_post_meta( $post->ID, self::PAYLOAD_HASH_META, $payload_hash );
 		}
 	}
+
+	/**
+	 * Trigger a partial post distribution.
+	 *
+	 * @param WP_Post|Outgoing_Post|int $post           The post object or ID.
+	 * @param string[]                  $post_data_keys The post data key to update.
+	 *
+	 * @return void|WP_Error The error if the payload is invalid.
+	 */
+	public static function distribute_post_partial( $post, $post_data_keys ) {
+		if ( ! class_exists( 'Newspack\Data_Events' ) ) {
+			return;
+		}
+		if ( is_string( $post_data_keys ) ) {
+			$post_data_keys = [ $post_data_keys ];
+		}
+		if ( $post instanceof Outgoing_Post ) {
+			$distributed_post = $post;
+		} else {
+			$distributed_post = self::get_distributed_post( $post );
+		}
+		if ( $distributed_post ) {
+			$payload = $distributed_post->get_partial_payload( $post_data_keys );
+			if ( is_wp_error( $payload ) ) {
+				return $payload;
+			}
+			Data_Events::dispatch( 'network_post_updated', $payload );
+		}
+	}
 }
diff --git a/includes/content-distribution/class-incoming-post.php b/includes/content-distribution/class-incoming-post.php
index 6824a02..0e89e6f 100644
--- a/includes/content-distribution/class-incoming-post.php
+++ b/includes/content-distribution/class-incoming-post.php
@@ -87,9 +87,6 @@ public function __construct( $payload ) {
 			throw new \InvalidArgumentException( esc_html( $error->get_error_message() ) );
 		}
 
-		$this->payload         = $payload;
-		$this->network_post_id = $payload['network_post_id'];
-
 		if ( ! $post ) {
 			$post = $this->query_post();
 		}
@@ -98,6 +95,21 @@ public function __construct( $payload ) {
 			$this->ID      = $post->ID;
 			$this->post    = $post;
 		}
+
+		// Handle partial payload.
+		if ( ! empty( $payload['partial'] ) ) {
+			if ( ! $this->ID ) {
+				throw new \InvalidArgumentException( esc_html( __( 'Partial payload requires an existing post.', 'newspack-network' ) ) );
+			}
+
+			$current_post_data    = $this->get_post_payload()['post_data'];
+			$payload['post_data'] = array_merge( $current_post_data, $payload['post_data'] );
+
+			unset( $payload['partial'] );
+		}
+
+		$this->payload         = $payload;
+		$this->network_post_id = $payload['network_post_id'];
 	}
 
 	/**
@@ -394,6 +406,19 @@ protected function update_payload( $payload ) {
 			return $error;
 		}
 
+		/**
+		 * Handle partial payload
+		 */
+		if ( ! empty( $payload['partial'] ) ) {
+			$current_payload = $this->get_post_payload();
+			if ( ! $this->ID ) {
+				self::log( 'Partial payload requires an existing post.' );
+				return new WP_Error( 'partial_payload', __( 'Partial payload requires an existing post.', 'newspack-network' ) );
+			}
+			$payload['post_data'] = array_merge( $current_payload['post_data'], $payload['post_data'] );
+			unset( $payload['partial'] );
+		}
+
 		// Do not update if network post ID mismatches.
 		if ( $this->network_post_id !== $payload['network_post_id'] ) {
 			return new WP_Error( 'mismatched_post_id', __( 'Mismatched post ID.', 'newspack-network' ) );
diff --git a/includes/content-distribution/class-outgoing-post.php b/includes/content-distribution/class-outgoing-post.php
index c51537f..3ce75ce 100644
--- a/includes/content-distribution/class-outgoing-post.php
+++ b/includes/content-distribution/class-outgoing-post.php
@@ -228,6 +228,43 @@ public function get_payload( $status_on_create = 'draft' ) {
 		];
 	}
 
+	/**
+	 * Get a partial payload for distribution.
+	 *
+	 * @param string[] $post_data_keys Keys in the post_data array to include in
+	 *                                 the partial payload.
+	 *
+	 * @return array|WP_Error The partial payload or WP_Error if any of the keys were not found.
+	 */
+	public function get_partial_payload( $post_data_keys ) {
+		if ( is_string( $post_data_keys ) ) {
+			$post_data_keys = [ $post_data_keys ];
+		}
+
+		$payload = $this->get_payload();
+		foreach ( $post_data_keys as $post_data_key ) {
+			if ( ! isset( $payload['post_data'][ $post_data_key ] ) ) {
+				return new WP_Error( 'key_not_found', __( 'Key not found in payload.', 'newspack-network' ) );
+			}
+		}
+
+		// Mark the payload as partial.
+		$payload['partial'] = true;
+
+		$post_data = [];
+		foreach ( $post_data_keys as $post_data_key ) {
+			$post_data[ $post_data_key ] = $payload['post_data'][ $post_data_key ];
+		}
+
+		// Always add the date and modified date to the partial payload.
+		$post_data['date_gmt']     = $payload['post_data']['date_gmt'];
+		$post_data['modified_gmt'] = $payload['post_data']['modified_gmt'];
+
+		$payload['post_data'] = $post_data;
+
+		return $payload;
+	}
+
 	/**
 	 * Get the processed post content for distribution.
 	 *
diff --git a/tests/unit-tests/content-distribution/test-incoming-post.php b/tests/unit-tests/content-distribution/test-incoming-post.php
index efbcbe1..43aac98 100644
--- a/tests/unit-tests/content-distribution/test-incoming-post.php
+++ b/tests/unit-tests/content-distribution/test-incoming-post.php
@@ -481,4 +481,51 @@ public function test_status_on_create() {
 		$this->incoming_post->insert( $payload );
 		$this->assertSame( 'draft', get_post_status( $post_id ) );
 	}
+
+	/**
+	 * Test partial post payload update.
+	 */
+	public function test_partial_payload_insert() {
+		$payload = $this->get_sample_payload();
+
+		$post_id = $this->incoming_post->insert( $payload );
+
+		// Update the post payload with a partial update.
+		$payload['partial']   = true;
+		$payload['post_data'] = [
+			'title'        => 'Updated Title',
+			'date_gmt'     => $payload['post_data']['date_gmt'],
+			'modified_gmt' => $payload['post_data']['modified_gmt'],
+		];
+
+		$this->incoming_post->insert( $payload );
+
+		// Assert that the post title was updated and the content was not.
+		$this->assertSame( 'Updated Title', get_the_title( $post_id ) );
+		$this->assertSame( 'Content', get_post_field( 'post_content', $post_id ) );
+	}
+
+	/**
+	 * Test partial post pyload update on instantiating.
+	 */
+	public function test_partial_payload_instantiating() {
+		$payload = $this->get_sample_payload();
+
+		$this->incoming_post->insert( $payload );
+
+		// Make the payload a partial.
+		$payload['partial']   = true;
+		$payload['post_data'] = [
+			'title'        => 'Updated Title',
+			'date_gmt'     => $payload['post_data']['date_gmt'],
+			'modified_gmt' => $payload['post_data']['modified_gmt'],
+		];
+
+		$incoming_post = new Incoming_Post( $payload );
+		$incoming_post->insert();
+
+		// Assert that the post title was updated and the content was not.
+		$this->assertSame( 'Updated Title', get_the_title( $post_id ) );
+		$this->assertSame( 'Content', get_post_field( 'post_content', $post_id ) );
+	}
 }
diff --git a/tests/unit-tests/content-distribution/test-outgoing-post.php b/tests/unit-tests/content-distribution/test-outgoing-post.php
index 3b48fb4..7213b7e 100644
--- a/tests/unit-tests/content-distribution/test-outgoing-post.php
+++ b/tests/unit-tests/content-distribution/test-outgoing-post.php
@@ -197,4 +197,16 @@ public function test_ignored_taxonomies() {
 		$payload = $this->outgoing_post->get_payload();
 		$this->assertTrue( empty( $payload['post_data']['taxonomy'][ $taxonomy ] ) );
 	}
+
+	/**
+	 * Test get partial payload.
+	 */
+	public function test_get_partial_payload() {
+		$partial_payload = $this->outgoing_post->get_partial_payload( 'post_meta' );
+
+		$this->assertArrayHasKey( 'post_meta', $partial_payload['post_data'] );
+		$this->assertArrayHasKey( 'date_gmt', $partial_payload['post_data'] );
+		$this->assertArrayHasKey( 'modified_gmt', $partial_payload['post_data'] );
+		$this->assertArrayNotHasKey( 'title', $partial_payload['post_data'] );
+	}
 }

From 8cd95575fc7e5a4b7234d47d6fb5426abfe2f6c5 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 16:56:53 -0300
Subject: [PATCH 02/13] fix: typo

---
 includes/class-content-distribution.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index 36bd4e4..8c66dac 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -201,7 +201,7 @@ public static function handle_postmeta_update( $meta_id, $object_id, $meta_key )
 		) {
 			return;
 		}
-		self::queue_post_distribution( $post->ID, 'post_meta' );
+		self::queue_post_distribution( $object_id, 'post_meta' );
 	}
 
 	/**

From 31afc86778bc4f066ace3bc040fe12977aca96c5 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 16:57:19 -0300
Subject: [PATCH 03/13] chore: restore for readbility

---
 includes/class-content-distribution.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index 8c66dac..36bd4e4 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -201,7 +201,7 @@ public static function handle_postmeta_update( $meta_id, $object_id, $meta_key )
 		) {
 			return;
 		}
-		self::queue_post_distribution( $object_id, 'post_meta' );
+		self::queue_post_distribution( $post->ID, 'post_meta' );
 	}
 
 	/**

From 143d197b105032d81ab201db098e633435603538 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 17:16:45 -0300
Subject: [PATCH 04/13] fix: ensure payload is present for post query

---
 includes/class-content-distribution.php       |  2 +-
 .../class-incoming-post.php                   | 67 ++++++++++++-------
 .../test-incoming-post.php                    |  5 +-
 3 files changed, 45 insertions(+), 29 deletions(-)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index 36bd4e4..a602079 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -424,7 +424,7 @@ public static function distribute_post( $post, $status_on_create = 'draft' ) {
 	 * Trigger a partial post distribution.
 	 *
 	 * @param WP_Post|Outgoing_Post|int $post           The post object or ID.
-	 * @param string[]                  $post_data_keys The post data key to update.
+	 * @param string[]                  $post_data_keys The post data keys to update.
 	 *
 	 * @return void|WP_Error The error if the payload is invalid.
 	 */
diff --git a/includes/content-distribution/class-incoming-post.php b/includes/content-distribution/class-incoming-post.php
index 0e89e6f..137b799 100644
--- a/includes/content-distribution/class-incoming-post.php
+++ b/includes/content-distribution/class-incoming-post.php
@@ -87,29 +87,26 @@ public function __construct( $payload ) {
 			throw new \InvalidArgumentException( esc_html( $error->get_error_message() ) );
 		}
 
+		$this->payload         = $payload;
+		$this->network_post_id = $payload['network_post_id'];
+
 		if ( ! $post ) {
 			$post = $this->query_post();
 		}
 
 		if ( $post ) {
-			$this->ID      = $post->ID;
-			$this->post    = $post;
+			$this->ID   = $post->ID;
+			$this->post = $post;
 		}
 
 		// Handle partial payload.
 		if ( ! empty( $payload['partial'] ) ) {
-			if ( ! $this->ID ) {
-				throw new \InvalidArgumentException( esc_html( __( 'Partial payload requires an existing post.', 'newspack-network' ) ) );
+			$payload = $this->get_payload_from_partial( $payload );
+			if ( is_wp_error( $payload ) ) {
+				throw new \InvalidArgumentException( esc_html( $payload->get_error_message() ) );
 			}
-
-			$current_post_data    = $this->get_post_payload()['post_data'];
-			$payload['post_data'] = array_merge( $current_post_data, $payload['post_data'] );
-
-			unset( $payload['partial'] );
+			$this->payload = $payload;
 		}
-
-		$this->payload         = $payload;
-		$this->network_post_id = $payload['network_post_id'];
 	}
 
 	/**
@@ -185,6 +182,31 @@ protected function get_post_payload() {
 		return get_post_meta( $this->ID, self::PAYLOAD_META, true );
 	}
 
+	/**
+	 * Get payload from partial.
+	 *
+	 * @param array $payload The partial payload.
+	 *
+	 * @return array|WP_Error The full payload or WP_Error on failure.
+	 */
+	protected function get_payload_from_partial( $payload ) {
+		if ( ! $this->ID ) {
+			return new WP_Error( 'missing_post', __( 'Partial payload requires an existing post.', 'newspack-network' ) );
+		}
+
+		$current_payload       = $this->get_post_payload();
+		$current_payload_error = self::get_payload_error( $current_payload );
+		if ( is_wp_error( $current_payload_error ) ) {
+			return $current_payload_error->get_error_message();
+		}
+
+		$payload['post_data'] = array_merge( $current_payload['post_data'], $payload['post_data'] );
+
+		unset( $payload['partial'] );
+
+		return $payload;
+	}
+
 	/**
 	 * Get the post's original site URL.
 	 *
@@ -406,24 +428,19 @@ protected function update_payload( $payload ) {
 			return $error;
 		}
 
-		/**
-		 * Handle partial payload
-		 */
-		if ( ! empty( $payload['partial'] ) ) {
-			$current_payload = $this->get_post_payload();
-			if ( ! $this->ID ) {
-				self::log( 'Partial payload requires an existing post.' );
-				return new WP_Error( 'partial_payload', __( 'Partial payload requires an existing post.', 'newspack-network' ) );
-			}
-			$payload['post_data'] = array_merge( $current_payload['post_data'], $payload['post_data'] );
-			unset( $payload['partial'] );
-		}
-
 		// Do not update if network post ID mismatches.
 		if ( $this->network_post_id !== $payload['network_post_id'] ) {
 			return new WP_Error( 'mismatched_post_id', __( 'Mismatched post ID.', 'newspack-network' ) );
 		}
 
+		// Handle partial payload.
+		if ( ! empty( $payload['partial'] ) ) {
+			$payload = $this->get_payload_from_partial( $payload );
+			if ( is_wp_error( $payload ) ) {
+				return $payload;
+			}
+		}
+
 		$this->payload = $payload;
 	}
 
diff --git a/tests/unit-tests/content-distribution/test-incoming-post.php b/tests/unit-tests/content-distribution/test-incoming-post.php
index 43aac98..d77e82e 100644
--- a/tests/unit-tests/content-distribution/test-incoming-post.php
+++ b/tests/unit-tests/content-distribution/test-incoming-post.php
@@ -509,11 +509,10 @@ public function test_partial_payload_insert() {
 	 * Test partial post pyload update on instantiating.
 	 */
 	public function test_partial_payload_instantiating() {
-		$payload = $this->get_sample_payload();
-
-		$this->incoming_post->insert( $payload );
+		$this->incoming_post->insert();
 
 		// Make the payload a partial.
+		$payload              = $this->get_sample_payload();
 		$payload['partial']   = true;
 		$payload['post_data'] = [
 			'title'        => 'Updated Title',

From 667fef9ae89c7ad5d67ca1a6e9c8e89db6e999c1 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 17:18:42 -0300
Subject: [PATCH 05/13] fix: restore $post_id for test

---
 tests/unit-tests/content-distribution/test-incoming-post.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/unit-tests/content-distribution/test-incoming-post.php b/tests/unit-tests/content-distribution/test-incoming-post.php
index d77e82e..e9d72d7 100644
--- a/tests/unit-tests/content-distribution/test-incoming-post.php
+++ b/tests/unit-tests/content-distribution/test-incoming-post.php
@@ -509,7 +509,7 @@ public function test_partial_payload_insert() {
 	 * Test partial post pyload update on instantiating.
 	 */
 	public function test_partial_payload_instantiating() {
-		$this->incoming_post->insert();
+		$post_id = $this->incoming_post->insert();
 
 		// Make the payload a partial.
 		$payload              = $this->get_sample_payload();

From 01534806a69be8254637811afe99b2993f5c932a Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 17:20:00 -0300
Subject: [PATCH 06/13] chore: standardize test

---
 .../content-distribution/test-incoming-post.php     | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/tests/unit-tests/content-distribution/test-incoming-post.php b/tests/unit-tests/content-distribution/test-incoming-post.php
index e9d72d7..03c7c7b 100644
--- a/tests/unit-tests/content-distribution/test-incoming-post.php
+++ b/tests/unit-tests/content-distribution/test-incoming-post.php
@@ -483,14 +483,13 @@ public function test_status_on_create() {
 	}
 
 	/**
-	 * Test partial post payload update.
+	 * Test partial post payload on insert.
 	 */
 	public function test_partial_payload_insert() {
-		$payload = $this->get_sample_payload();
-
-		$post_id = $this->incoming_post->insert( $payload );
+		$post_id = $this->incoming_post->insert();
 
-		// Update the post payload with a partial update.
+		// Make the payload a partial.
+		$payload              = $this->get_sample_payload();
 		$payload['partial']   = true;
 		$payload['post_data'] = [
 			'title'        => 'Updated Title',
@@ -506,9 +505,9 @@ public function test_partial_payload_insert() {
 	}
 
 	/**
-	 * Test partial post pyload update on instantiating.
+	 * Test partial post payload on instantiation.
 	 */
-	public function test_partial_payload_instantiating() {
+	public function test_partial_payload_instantiation() {
 		$post_id = $this->incoming_post->insert();
 
 		// Make the payload a partial.

From f58bb23a090dd1def1c049a86a8ae1ac0878490c Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 17:53:39 -0300
Subject: [PATCH 07/13] test: queue post distribution

---
 includes/class-content-distribution.php       |  7 +++++
 .../test-content-distribution.php             | 26 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index a602079..5f3beea 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -105,6 +105,13 @@ public static function queue_post_distribution( $post_id, $post_data_key = null
 		self::$queued_distributions[ $post_id ][] = $post_data_key;
 	}
 
+	/**
+	 * Get queued post distributions.
+	 */
+	public static function get_queued_distributions() {
+		return self::$queued_distributions;
+	}
+
 	/**
 	 * Distribute queued posts.
 	 */
diff --git a/tests/unit-tests/content-distribution/test-content-distribution.php b/tests/unit-tests/content-distribution/test-content-distribution.php
index 748339e..cb4cd7f 100644
--- a/tests/unit-tests/content-distribution/test-content-distribution.php
+++ b/tests/unit-tests/content-distribution/test-content-distribution.php
@@ -7,6 +7,7 @@
 
 namespace Test\Content_Distribution;
 
+use Newspack_Network\Content_Distribution as Content_Distribution_Class;
 use Newspack_Network\Content_Distribution\Outgoing_Post;
 use Newspack_Network\Hub\Node as Hub_Node;
 
@@ -64,4 +65,29 @@ public function test_update_distributed_post_meta() {
 		$result = update_post_meta( $post_id, Outgoing_Post::DISTRIBUTED_POST_META, [ 'https://node.test', 'https://other-node.test' ] );
 		$this->assertNotFalse( $result );
 	}
+
+	/**
+	 * Test queue post distribution.
+	 */
+	public function test_queue_post_distribution() {
+		$post_id = $this->factory->post->create();
+
+		// Queue post meta for distribution.
+		Content_Distribution_Class::queue_post_distribution( $post_id, 'post_meta' );
+		$queue = Content_Distribution_Class::get_queued_distributions();
+		$this->assertArrayHasKey( $post_id, $queue );
+		$this->assertSame( [ 'post_meta' ], $queue[ $post_id ] );
+
+		// Queue full post for distribution.
+		Content_Distribution_Class::queue_post_distribution( $post_id );
+		$queue = Content_Distribution_Class::get_queued_distributions();
+		$this->assertArrayHasKey( $post_id, $queue );
+		$this->assertTrue( $queue[ $post_id ] );
+
+		// Queue another attribute for distribution.
+		$queue = Content_Distribution_Class::get_queued_distributions( $post_id, 'taxonomy' );
+		$this->assertArrayHasKey( $post_id, $queue );
+		// Assert that the post is still queued for full distribution.
+		$this->assertTrue( $queue[ $post_id ] );
+	}
 }

From d84ded00ad9b18e7ec80944a73b6b01194120d6b Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 17:59:01 -0300
Subject: [PATCH 08/13] test: increase coverage for outgoing_post

---
 .../test-outgoing-post.php                    | 26 ++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/tests/unit-tests/content-distribution/test-outgoing-post.php b/tests/unit-tests/content-distribution/test-outgoing-post.php
index 7213b7e..1b4cf8a 100644
--- a/tests/unit-tests/content-distribution/test-outgoing-post.php
+++ b/tests/unit-tests/content-distribution/test-outgoing-post.php
@@ -204,9 +204,29 @@ public function test_ignored_taxonomies() {
 	public function test_get_partial_payload() {
 		$partial_payload = $this->outgoing_post->get_partial_payload( 'post_meta' );
 
-		$this->assertArrayHasKey( 'post_meta', $partial_payload['post_data'] );
-		$this->assertArrayHasKey( 'date_gmt', $partial_payload['post_data'] );
-		$this->assertArrayHasKey( 'modified_gmt', $partial_payload['post_data'] );
+		$payload = $this->outgoing_post->get_payload();
+		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
+		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
+		$this->assertSame( $payload['post_data']['date_gmt'], $partial_payload['post_data']['date_gmt'] );
+		$this->assertSame( $payload['post_data']['modified_gmt'], $partial_payload['post_data']['modified_gmt'] );
+		$this->assertArrayNotHasKey( 'title', $partial_payload['post_data'] );
+		$this->assertArrayNotHasKey( 'content', $partial_payload['post_data'] );
+		$this->assertArrayNotHasKey( 'taxonomy', $partial_payload['post_data'] );
+	}
+
+	/**
+	 * Test get partial payload multiple keys.
+	 */
+	public function test_get_partial_payload_multiple_keys() {
+		$partial_payload = $this->outgoing_post->get_partial_payload( [ 'post_meta', 'taxonomy' ] );
+
+		$payload = $this->outgoing_post->get_payload();
+		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
+		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
+		$this->assertSame( $payload['post_data']['taxonomy'], $partial_payload['post_data']['taxonomy'] );
+		$this->assertSame( $payload['post_data']['date_gmt'], $partial_payload['post_data']['date_gmt'] );
+		$this->assertSame( $payload['post_data']['modified_gmt'], $partial_payload['post_data']['modified_gmt'] );
 		$this->assertArrayNotHasKey( 'title', $partial_payload['post_data'] );
+		$this->assertArrayNotHasKey( 'content', $partial_payload['post_data'] );
 	}
 }

From 278e54a79c30feb2a541e88b8c84fd5f7159e179 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 18:03:04 -0300
Subject: [PATCH 09/13] test: fix queue post distribution test

---
 .../content-distribution/test-content-distribution.php      | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/unit-tests/content-distribution/test-content-distribution.php b/tests/unit-tests/content-distribution/test-content-distribution.php
index cb4cd7f..99a7d16 100644
--- a/tests/unit-tests/content-distribution/test-content-distribution.php
+++ b/tests/unit-tests/content-distribution/test-content-distribution.php
@@ -81,12 +81,12 @@ public function test_queue_post_distribution() {
 		// Queue full post for distribution.
 		Content_Distribution_Class::queue_post_distribution( $post_id );
 		$queue = Content_Distribution_Class::get_queued_distributions();
-		$this->assertArrayHasKey( $post_id, $queue );
+		// Assert that the post is queued for full distribution (= true).
 		$this->assertTrue( $queue[ $post_id ] );
 
 		// Queue another attribute for distribution.
-		$queue = Content_Distribution_Class::get_queued_distributions( $post_id, 'taxonomy' );
-		$this->assertArrayHasKey( $post_id, $queue );
+		Content_Distribution_Class::queue_post_distribution( $post_id, 'post_meta' );
+		$queue = Content_Distribution_Class::get_queued_distributions();
 		// Assert that the post is still queued for full distribution.
 		$this->assertTrue( $queue[ $post_id ] );
 	}

From 51fa9851224e82f35735ccfa9e7941d6cac98234 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 19:02:01 -0300
Subject: [PATCH 10/13] test: assert payload partial property

---
 includes/class-content-distribution.php                      | 4 +++-
 tests/unit-tests/content-distribution/test-outgoing-post.php | 2 ++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/includes/class-content-distribution.php b/includes/class-content-distribution.php
index 5f3beea..73f5a8a 100644
--- a/includes/class-content-distribution.php
+++ b/includes/class-content-distribution.php
@@ -51,7 +51,9 @@ public static function init() {
 		add_filter( 'newspack_webhooks_request_priority', [ __CLASS__, 'webhooks_request_priority' ], 10, 2 );
 		add_filter( 'update_post_metadata', [ __CLASS__, 'maybe_short_circuit_distributed_meta' ], 10, 4 );
 		add_action( 'wp_after_insert_post', [ __CLASS__, 'handle_post_updated' ] );
-		add_action( 'updated_postmeta', [ __CLASS__, 'handle_postmeta_update' ], 10, 3 );
+		add_action( 'updated_post_meta', [ __CLASS__, 'handle_postmeta_update' ], 10, 3 );
+		add_action( 'added_post_meta', [ __CLASS__, 'handle_postmeta_update' ], 10, 3 );
+		add_action( 'deleted_post_meta', [ __CLASS__, 'handle_postmeta_update' ], 10, 3 );
 		add_action( 'before_delete_post', [ __CLASS__, 'handle_post_deleted' ] );
 		add_action( 'newspack_network_incoming_post_inserted', [ __CLASS__, 'handle_incoming_post_inserted' ], 10, 3 );
 
diff --git a/tests/unit-tests/content-distribution/test-outgoing-post.php b/tests/unit-tests/content-distribution/test-outgoing-post.php
index 1b4cf8a..f48f4fd 100644
--- a/tests/unit-tests/content-distribution/test-outgoing-post.php
+++ b/tests/unit-tests/content-distribution/test-outgoing-post.php
@@ -205,6 +205,7 @@ public function test_get_partial_payload() {
 		$partial_payload = $this->outgoing_post->get_partial_payload( 'post_meta' );
 
 		$payload = $this->outgoing_post->get_payload();
+		$this->assertTrue( $payload['partial'] );
 		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
 		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
 		$this->assertSame( $payload['post_data']['date_gmt'], $partial_payload['post_data']['date_gmt'] );
@@ -221,6 +222,7 @@ public function test_get_partial_payload_multiple_keys() {
 		$partial_payload = $this->outgoing_post->get_partial_payload( [ 'post_meta', 'taxonomy' ] );
 
 		$payload = $this->outgoing_post->get_payload();
+		$this->assertTrue( $payload['partial'] );
 		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
 		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
 		$this->assertSame( $payload['post_data']['taxonomy'], $partial_payload['post_data']['taxonomy'] );

From d50d94ce32c6b9986f251b485cb238614042fa07 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 19:03:41 -0300
Subject: [PATCH 11/13] test: fix typo

---
 tests/unit-tests/content-distribution/test-outgoing-post.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/unit-tests/content-distribution/test-outgoing-post.php b/tests/unit-tests/content-distribution/test-outgoing-post.php
index f48f4fd..017bcb8 100644
--- a/tests/unit-tests/content-distribution/test-outgoing-post.php
+++ b/tests/unit-tests/content-distribution/test-outgoing-post.php
@@ -205,7 +205,7 @@ public function test_get_partial_payload() {
 		$partial_payload = $this->outgoing_post->get_partial_payload( 'post_meta' );
 
 		$payload = $this->outgoing_post->get_payload();
-		$this->assertTrue( $payload['partial'] );
+		$this->assertTrue( $partial_payload['partial'] );
 		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
 		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
 		$this->assertSame( $payload['post_data']['date_gmt'], $partial_payload['post_data']['date_gmt'] );
@@ -222,7 +222,7 @@ public function test_get_partial_payload_multiple_keys() {
 		$partial_payload = $this->outgoing_post->get_partial_payload( [ 'post_meta', 'taxonomy' ] );
 
 		$payload = $this->outgoing_post->get_payload();
-		$this->assertTrue( $payload['partial'] );
+		$this->assertTrue( $partial_payload['partial'] );
 		$this->assertSame( $payload['network_post_id'], $partial_payload['network_post_id'] );
 		$this->assertSame( $payload['post_data']['post_meta'], $partial_payload['post_data']['post_meta'] );
 		$this->assertSame( $payload['post_data']['taxonomy'], $partial_payload['post_data']['taxonomy'] );

From 3ce6f40413d6e04f8332c16e5d8902187c22c73d Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Tue, 28 Jan 2025 19:13:17 -0300
Subject: [PATCH 12/13] test: partial payload exception

---
 .../test-incoming-post.php                    | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/unit-tests/content-distribution/test-incoming-post.php b/tests/unit-tests/content-distribution/test-incoming-post.php
index 03c7c7b..4686c8b 100644
--- a/tests/unit-tests/content-distribution/test-incoming-post.php
+++ b/tests/unit-tests/content-distribution/test-incoming-post.php
@@ -526,4 +526,24 @@ public function test_partial_payload_instantiation() {
 		$this->assertSame( 'Updated Title', get_the_title( $post_id ) );
 		$this->assertSame( 'Content', get_post_field( 'post_content', $post_id ) );
 	}
+
+	/**
+	 * Test partial payload on missing post.
+	 */
+	public function test_partial_payload_missing_post() {
+		$payload = $this->get_sample_payload();
+
+		// Make the payload a partial.
+		$payload['partial']   = true;
+		$payload['post_data'] = [
+			'title'        => 'Updated Title',
+			'date_gmt'     => $payload['post_data']['date_gmt'],
+			'modified_gmt' => $payload['post_data']['modified_gmt'],
+		];
+
+		// Assert that instantiating a partial payload will throw an exception.
+		$this->expectException( \InvalidArgumentException::class );
+		$this->expectExceptionMessage( 'Partial payload requires an existing post.' );
+		new Incoming_Post( $payload );
+	}
 }

From ac91081baaf6d1312071dbdddb85e8644e7a78c7 Mon Sep 17 00:00:00 2001
From: Miguel Peixe <miguel.peixe@automattic.com>
Date: Wed, 29 Jan 2025 09:11:18 -0300
Subject: [PATCH 13/13] fix: error return

---
 includes/content-distribution/class-incoming-post.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/includes/content-distribution/class-incoming-post.php b/includes/content-distribution/class-incoming-post.php
index 137b799..675e8ec 100644
--- a/includes/content-distribution/class-incoming-post.php
+++ b/includes/content-distribution/class-incoming-post.php
@@ -197,7 +197,7 @@ protected function get_payload_from_partial( $payload ) {
 		$current_payload       = $this->get_post_payload();
 		$current_payload_error = self::get_payload_error( $current_payload );
 		if ( is_wp_error( $current_payload_error ) ) {
-			return $current_payload_error->get_error_message();
+			return $current_payload_error;
 		}
 
 		$payload['post_data'] = array_merge( $current_payload['post_data'], $payload['post_data'] );