Add the Package_Version_Tracker class

projects/packages/backup/actions.php

@@ -14,3 +14,6 @@
 
 // Register REST routes.
 add_action( 'rest_api_init', array( 'Automattic\\Jetpack\\Backup\\REST_Controller', 'register_rest_routes' ) );
+
+// Set up package version hook.
+add_filter( 'jetpack_package_versions', 'Automattic\\Jetpack\\Backup\\Package_Version::send_package_version_to_tracker' );

projects/packages/backup/changelog/update-package_version_filter

@@ -0,0 +1,4 @@
+Significance: patch
+Type: added
+
+Add package version tracking.

projects/packages/backup/src/class-package-version.php

@@ -14,4 +14,18 @@ class Package_Version {
 
 	const PACKAGE_VERSION = '1.1.2-alpha';
 
+	const PACKAGE_SLUG = 'backup';
+
+	/**
+	 * Adds the package slug and version to the package version tracker's data.
+	 *
+	 * @param array $package_versions The package version array.
+	 *
+	 * @return array The packge version array.
+	 */
+	public static function send_package_version_to_tracker( $package_versions ) {
+		$package_versions[ self::PACKAGE_SLUG ] = self::PACKAGE_VERSION;
+		return $package_versions;
+	}
+
 }

projects/packages/backup/tests/php/test-package-version.php

@@ -0,0 +1,46 @@
+<?php // phpcs:ignore WordPress.Files.FileName.InvalidClassFileName
+
+namespace Automattic\Jetpack\Backup;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for the Package_Version class.
+ *
+ * @package automattic/jetpack-backup
+ */
+class Test_Package_Version extends TestCase {
+
+	/**
+	 * Tests that the backup package version is added to the package verions array obtained by the
+	 * Package_Version_Tracker.
+	 */
+	public function test_send_package_version_to_tracker_empty_array() {
+		$expected = array(
+			Package_Version::PACKAGE_SLUG => Package_Version::PACKAGE_VERSION,
+		);
+
+		add_filter( 'jetpack_package_versions', __NAMESPACE__ . '\Package_Version::send_package_version_to_tracker' );
+
+		$this->assertSame( $expected, apply_filters( 'jetpack_package_versions', array() ) );
+	}
+
+	/**
+	 * Tests that the backup package version is added to the package verions array obtained by the
+	 * Package_Version_Tracker.
+	 */
+	public function test_send_package_version_to_tracker_existing_array() {
+		$existing_array = array(
+			'test-package-slug' => '1.0.0',
+		);
+
+		$expected = array_merge(
+			$existing_array,
+			array( Package_Version::PACKAGE_SLUG => Package_Version::PACKAGE_VERSION )
+		);
+
+		add_filter( 'jetpack_package_versions', __NAMESPACE__ . '\Package_Version::send_package_version_to_tracker' );
+
+		$this->assertSame( $expected, apply_filters( 'jetpack_package_versions', $existing_array ) );
+	}
+}

projects/packages/connection/changelog/update-package_version_filter

@@ -0,0 +1,4 @@
+Significance: patch
+Type: added
+
+Add package version tracking.

projects/packages/connection/src/class-manager.php

@@ -94,6 +94,7 @@ public static function configure() {
 
 		if ( $manager->is_connected() ) {
 			add_filter( 'xmlrpc_methods', array( $manager, 'public_xmlrpc_methods' ) );
+			add_filter( 'plugins_loaded', array( new Package_Version_Tracker(), 'maybe_update_package_versions' ) );
 		}
 
 		add_action( 'rest_api_init', array( $manager, 'initialize_rest_api_registration_connector' ) );
@@ -108,6 +109,9 @@ public static function configure() {
 		add_filter( 'jetpack_heartbeat_stats_array', array( $manager, 'add_stats_to_heartbeat' ) );
 
 		Webhooks::init( $manager );
+
+		// Set up package version hook.
+		add_filter( 'jetpack_package_versions', __NAMESPACE__ . '\Package_Version::send_package_version_to_tracker' );
 	}
 
 	/**

projects/packages/connection/src/class-package-version-tracker.php

@@ -0,0 +1,83 @@
+<?php
+/**
+ * The Package_Version_Tracker class.
+ *
+ * @package automattic/jetpack-connection
+ */
+
+namespace Automattic\Jetpack\Connection;
+
+/**
+ * The Package_Version_Tracker class.
+ */
+class Package_Version_Tracker {
+
+	const PACKAGE_VERSION_OPTION = 'jetpack_package_versions';
+
+	/**
+	 * Uses the jetpack_package_versions filter to obtain the package versions from packages that need
+	 * version tracking. If the package versions have changed, updates the option and notifies WPCOM.
+	 */
+	public function maybe_update_package_versions() {
+		/**
+		 * Obtains the package versions.
+		 *
+		 * @since $$next_version$$
+		 *
+		 * @param array An associative array of Jetpack package slugs and their corresponding versions as key/value pairs.
+		 */
+		$filter_versions = apply_filters( 'jetpack_package_versions', array() );
+
+		if ( ! is_array( $filter_versions ) ) {
+			return;
+		}
+
+		$option_versions = get_option( self::PACKAGE_VERSION_OPTION, array() );
+
+		foreach ( $filter_versions as $package => $version ) {
+			if ( ! is_string( $package ) || ! is_string( $version ) ) {
+				unset( $filter_versions[ $package ] );
+			}
+		}
+
+		if ( ! is_array( $option_versions )
+			|| count( array_diff_assoc( $filter_versions, $option_versions ) )
+			|| count( array_diff_assoc( $option_versions, $filter_versions ) )
+		) {
+			$this->update_package_versions_option( $filter_versions );
+		}
+	}
+
+	/**
+	 * Updates the package versions:
+	 *   - Sends the updated package versions to wpcom.
+	 *   - Updates the 'jetpack_package_versions' option.
+	 *
+	 * @param array $package_versions The package versions.
+	 */
+	protected function update_package_versions_option( $package_versions ) {
+		$site_id = \Jetpack_Options::get_option( 'id' );
+
+		$body = wp_json_encode(
+			array(
+				'package_versions' => $package_versions,
+			)
+		);
+
+		$response = Client::wpcom_json_api_request_as_blog(
+			sprintf( '/sites/%d/jetpack-package-versions', $site_id ),
+			'2',
+			array(
+				'headers' => array( 'content-type' => 'application/json' ),
+				'method'  => 'POST',
+			),
+			$body,
+			'wpcom'
+		);
+
+		if ( 200 === wp_remote_retrieve_response_code( $response ) ) {
+			update_option( self::PACKAGE_VERSION_OPTION, $package_versions );
+		}
+	}
+
+}

projects/packages/connection/src/class-package-version.php

@@ -12,5 +12,19 @@
  */
 class Package_Version {
 
-	const PACKAGE_VERSION = '1.30.1';
+	const PACKAGE_VERSION = '1.30.2-alpha';
+
+	const PACKAGE_SLUG = 'connection';
+
+	/**
+	 * Adds the package slug and version to the package version tracker's data.
+	 *
+	 * @param array $package_versions The package version array.
+	 *
+	 * @return array The packge version array.
+	 */
+	public static function send_package_version_to_tracker( $package_versions ) {
+		$package_versions[ self::PACKAGE_SLUG ] = self::PACKAGE_VERSION;
+		return $package_versions;
+	}
 }

projects/packages/connection/tests/php/test-package-version.php

@@ -0,0 +1,46 @@
+<?php // phpcs:ignore WordPress.Files.FileName.InvalidClassFileName
+
+namespace Automattic\Jetpack\Connection;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for the Package_Version class.
+ *
+ * @package automattic/jetpack-connection
+ */
+class Test_Package_Version extends TestCase {
+
+	/**
+	 * Tests that the connction package version is added to the package verions array obtained by the
+	 * Package_Version_Tracker.
+	 */
+	public function test_send_package_version_to_tracker_empty_array() {
+		$expected = array(
+			Package_Version::PACKAGE_SLUG => Package_Version::PACKAGE_VERSION,
+		);
+
+		add_filter( 'jetpack_package_versions', __NAMESPACE__ . '\Package_Version::send_package_version_to_tracker' );
+
+		$this->assertSame( $expected, apply_filters( 'jetpack_package_versions', array() ) );
+	}
+
+	/**
+	 * Tests that the connection package version is added to the package verions array obtained by the
+	 * Package_Version_Tracker.
+	 */
+	public function test_send_package_version_to_tracker_existing_array() {
+		$existing_array = array(
+			'test-package-slug' => '1.0.0',
+		);
+
+		$expected = array_merge(
+			$existing_array,
+			array( Package_Version::PACKAGE_SLUG => Package_Version::PACKAGE_VERSION )
+		);
+
+		add_filter( 'jetpack_package_versions', __NAMESPACE__ . '\Package_Version::send_package_version_to_tracker' );
+
+		$this->assertSame( $expected, apply_filters( 'jetpack_package_versions', $existing_array ) );
+	}
+}