autoloader: Preload classes on plugin upgrade to avoid mid-upgrade fatals

projects/packages/autoloader/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+On plugin update, pre-load all (non-PSR-4) classes from the plugin to avoid mid-upgrade fatals.

projects/packages/autoloader/composer.json

@@ -49,7 +49,7 @@
 			"link-template": "https://github.com/Automattic/jetpack-autoloader/compare/v${old}...v${new}"
 		},
 		"branch-alias": {
-			"dev-master": "2.10.x-dev"
+			"dev-master": "2.11.x-dev"
 		}
 	}
 }

projects/packages/autoloader/src/class-autoloader.php

@@ -77,6 +77,13 @@ public static function init( $container = null ) {
 		// Register a shutdown handler to clean up the autoloader.
 		$hook_manager->add_action( 'shutdown', new Shutdown_Handler( $plugins_handler, $cached_plugins, $was_included_by_autoloader ) );
 
+		// Register an upgrade handler to handle plugin upgrades.
+		$upgrade_handler = new Upgrade_Handler();
+		$hook_manager->add_filter( 'upgrader_pre_install', array( $upgrade_handler, 'upgrader_pre_install' ), 10, 2 );
+		// wp-cli never fires `delete_plugin` but always fires `pre_uninstall_plugin`, while core only conditionally fires `pre_uninstall_plugin` but always fires `delete_plugin`.
+		$hook_manager->add_action( 'delete_plugin', array( $upgrade_handler, 'delete_plugin' ), 10, 1 );
+		$hook_manager->add_action( 'pre_uninstall_plugin', array( $upgrade_handler, 'delete_plugin' ), 10, 1 );
+
 		// phpcs:enable Generic.Commenting.DocComment.MissingShort
 	}
 }

projects/packages/autoloader/src/class-container.php

@@ -119,6 +119,7 @@ private function register_dependencies() {
 		// Register any classes that we will use elsewhere.
 		require_once __DIR__ . '/class-version-loader.php';
 		require_once __DIR__ . '/class-shutdown-handler.php';
+		require_once __DIR__ . '/class-upgrade-handler.php';
 	}
 
 	/**

projects/packages/autoloader/src/class-upgrade-handler.php

@@ -0,0 +1,52 @@
+<?php
+/* HEADER */ // phpcs:ignore
+
+/**
+ * This class handles plugin upgrades and uninstalls.
+ */
+class Upgrade_Handler {
+
+	/**
+	 * Handles a plugin upgrade.
+	 *
+	 * @param bool|WP_Error $response Response.
+	 * @param array         $hook_extra Extra arguments passed to hooked filters.
+	 * @return bool|WP_Error Response
+	 */
+	public function upgrader_pre_install( $response, $hook_extra ) {
+		if ( isset( $hook_extra['plugin'] ) ) {
+			$this->load_plugin_classes( $hook_extra['plugin'] );
+		}
+		return $response;
+	}
+
+	/**
+	 * Handles a plugin deletion.
+	 *
+	 * @param string $plugin_file Path to the plugin file relative to the plugins directory.
+	 */
+	public function delete_plugin( $plugin_file ) {
+		$this->load_plugin_classes( $plugin_file );
+	}
+
+	/**
+	 * Load classes for a plugin.
+	 *
+	 * The intention here is to avoid errors on upgrade when a file is deleted,
+	 * by loading everything the autoloader knows about before the upgrade
+	 * happens.
+	 *
+	 * Note this can't load classes autoloaded by PSR-0 or PSR-4 unless an
+	 * optimized autoloader was used.
+	 *
+	 * See p9dueE-4c4-p2 for internal discussion.
+	 *
+	 * @param string $plugin Path to the plugin file relative to the plugins directory.
+	 */
+	private function load_plugin_classes( $plugin ) {
+		global $jetpack_autoloader_loader;
+		if ( isset( $jetpack_autoloader_loader ) && defined( 'WP_PLUGIN_DIR' ) ) {
+			$jetpack_autoloader_loader->load_classes_in_path( WP_PLUGIN_DIR . '/' . dirname( $plugin ) );
+		}
+	}
+}

projects/packages/autoloader/src/class-version-loader.php

@@ -85,6 +85,23 @@ public function load_filemap() {
 		}
 	}
 
+	/**
+	 * Load all of the (non-PSR-4) classes located under a path.
+	 *
+	 * @param string $path Path.
+	 */
+	public function load_classes_in_path( $path ) {
+		$path = rtrim( $path, '/' ) . '/';
+		$l    = strlen( $path );
+		foreach ( $this->classmap as $classname => $data ) {
+			if ( substr( $data['path'], 0, $l ) === $path && file_exists( $data['path'] ) ) {
+				// Use the autoloader instead of loading directly in case there's a PSR-4 class or
+				// something masking it.
+				class_exists( $classname, true );
+			}
+		}
+	}
+
 	/**
 	 * Compares different class sources and returns the newest.
 	 *

projects/plugins/backup/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Updated package dependencies.

projects/plugins/backup/composer.json

@@ -6,7 +6,7 @@
 	"require": {
 		"automattic/jetpack-assets": "1.17.x-dev",
 		"automattic/jetpack-admin-ui": "0.2.x-dev",
-		"automattic/jetpack-autoloader": "2.10.x-dev",
+		"automattic/jetpack-autoloader": "2.11.x-dev",
 		"automattic/jetpack-backup": "1.2.x-dev",
 		"automattic/jetpack-composer-plugin": "1.1.x-dev",
 		"automattic/jetpack-config": "1.6.x-dev",

projects/plugins/beta/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Updated package dependencies.

projects/plugins/beta/composer.json

@@ -8,7 +8,7 @@
 		"issues": "https://github.com/Automattic/jetpack/issues"
 	},
 	"require": {
-		"automattic/jetpack-autoloader": "2.10.x-dev",
+		"automattic/jetpack-autoloader": "2.11.x-dev",
 		"composer/semver": "3.2.7",
 		"erusev/parsedown": "1.7.4"
 	},

projects/plugins/boost/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Updated package dependencies.

projects/plugins/boost/composer.json

@@ -16,7 +16,7 @@
 		"ext-json": "*",
 		"automattic/jetpack-assets": "1.17.x-dev",
 		"automattic/jetpack-admin-ui": "0.2.x-dev",
-		"automattic/jetpack-autoloader": "2.10.x-dev",
+		"automattic/jetpack-autoloader": "2.11.x-dev",
 		"automattic/jetpack-composer-plugin": "1.1.x-dev",
 		"automattic/jetpack-config": "1.6.x-dev",
 		"automattic/jetpack-connection": "1.37.x-dev",

projects/plugins/jetpack/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: patch
+Type: other
+
+Updated package dependencies.

projects/plugins/jetpack/composer.json

@@ -14,7 +14,7 @@
 		"automattic/jetpack-a8c-mc-stats": "1.4.x-dev",
 		"automattic/jetpack-abtest": "1.9.x-dev",
 		"automattic/jetpack-assets": "1.17.x-dev",
-		"automattic/jetpack-autoloader": "2.10.x-dev",
+		"automattic/jetpack-autoloader": "2.11.x-dev",
 		"automattic/jetpack-backup": "1.2.x-dev",
 		"automattic/jetpack-blocks": "1.4.x-dev",
 		"automattic/jetpack-compat": "1.6.x-dev",

projects/plugins/vaultpress/changelog/add-autoloader-load-everything-on-plugin-update

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Updated package dependencies.

projects/plugins/vaultpress/composer.json

@@ -9,7 +9,7 @@
 	},
 	"require": {
 		"automattic/jetpack-logo": "1.5.x-dev",
-		"automattic/jetpack-autoloader": "2.10.x-dev"
+		"automattic/jetpack-autoloader": "2.11.x-dev"
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "1.0.3",

tools/cli/commands/build.js

@@ -679,7 +679,8 @@ async function buildProject( t ) {
 	}
 
 	// HACK: Create stubs to avoid upgrade errors. See https://github.com/Automattic/jetpack/pull/22431.
-	// Ideally we'll have fixed the upgrade errors by the time something else breaks, in which case this should be removed instead of extended.
+	// This should no longer be needed for upgrades when jetpack-autoloader 2.11+ is in use, but we should probably
+	// keep it around for a few versions for people still upgrading from older versions.
 	if ( t.project === 'plugins/jetpack' || t.project === 'plugins/backup' ) {
 		t.output( '\n=== Stubbing old vendor files for backward compatibility ===\n\n' );
 		const files = [