--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-plugin-dependencies.php Fri Sep 05 18:40:08 2025 +0200
@@ -0,0 +1,878 @@
+<?php
+/**
+ * WordPress Plugin Administration API: WP_Plugin_Dependencies class
+ *
+ * @package WordPress
+ * @subpackage Administration
+ * @since 6.5.0
+ */
+
+/**
+ * Core class for installing plugin dependencies.
+ *
+ * It is designed to add plugin dependencies as designated in the
+ * `Requires Plugins` header to a new view in the plugins install page.
+ */
+class WP_Plugin_Dependencies {
+
+ /**
+ * Holds 'get_plugins()'.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $plugins;
+
+ /**
+ * Holds plugin directory names to compare with cache.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $plugin_dirnames;
+
+ /**
+ * Holds sanitized plugin dependency slugs.
+ *
+ * Keyed on the dependent plugin's filepath,
+ * relative to the plugins directory.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $dependencies;
+
+ /**
+ * Holds an array of sanitized plugin dependency slugs.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $dependency_slugs;
+
+ /**
+ * Holds an array of dependent plugin slugs.
+ *
+ * Keyed on the dependent plugin's filepath,
+ * relative to the plugins directory.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $dependent_slugs;
+
+ /**
+ * Holds 'plugins_api()' data for plugin dependencies.
+ *
+ * @since 6.5.0
+ *
+ * @var array
+ */
+ protected static $dependency_api_data;
+
+ /**
+ * Holds plugin dependency filepaths, relative to the plugins directory.
+ *
+ * Keyed on the dependency's slug.
+ *
+ * @since 6.5.0
+ *
+ * @var string[]
+ */
+ protected static $dependency_filepaths;
+
+ /**
+ * An array of circular dependency pairings.
+ *
+ * @since 6.5.0
+ *
+ * @var array[]
+ */
+ protected static $circular_dependencies_pairs;
+
+ /**
+ * An array of circular dependency slugs.
+ *
+ * @since 6.5.0
+ *
+ * @var string[]
+ */
+ protected static $circular_dependencies_slugs;
+
+ /**
+ * Whether Plugin Dependencies have been initialized.
+ *
+ * @since 6.5.0
+ *
+ * @var bool
+ */
+ protected static $initialized = false;
+
+ /**
+ * Initializes by fetching plugin header and plugin API data.
+ *
+ * @since 6.5.0
+ */
+ public static function initialize() {
+ if ( false === self::$initialized ) {
+ self::read_dependencies_from_plugin_headers();
+ self::get_dependency_api_data();
+ self::$initialized = true;
+ }
+ }
+
+ /**
+ * Determines whether the plugin has plugins that depend on it.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return bool Whether the plugin has plugins that depend on it.
+ */
+ public static function has_dependents( $plugin_file ) {
+ return in_array( self::convert_to_slug( $plugin_file ), (array) self::$dependency_slugs, true );
+ }
+
+ /**
+ * Determines whether the plugin has plugin dependencies.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return bool Whether a plugin has plugin dependencies.
+ */
+ public static function has_dependencies( $plugin_file ) {
+ return isset( self::$dependencies[ $plugin_file ] );
+ }
+
+ /**
+ * Determines whether the plugin has active dependents.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return bool Whether the plugin has active dependents.
+ */
+ public static function has_active_dependents( $plugin_file ) {
+ require_once ABSPATH . '/wp-admin/includes/plugin.php';
+
+ $dependents = self::get_dependents( self::convert_to_slug( $plugin_file ) );
+ foreach ( $dependents as $dependent ) {
+ if ( is_plugin_active( $dependent ) ) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Gets filepaths of plugins that require the dependency.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slug The dependency's slug.
+ * @return array An array of dependent plugin filepaths, relative to the plugins directory.
+ */
+ public static function get_dependents( $slug ) {
+ $dependents = array();
+
+ foreach ( (array) self::$dependencies as $dependent => $dependencies ) {
+ if ( in_array( $slug, $dependencies, true ) ) {
+ $dependents[] = $dependent;
+ }
+ }
+
+ return $dependents;
+ }
+
+ /**
+ * Gets the slugs of plugins that the dependent requires.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The dependent plugin's filepath, relative to the plugins directory.
+ * @return array An array of dependency plugin slugs.
+ */
+ public static function get_dependencies( $plugin_file ) {
+ if ( isset( self::$dependencies[ $plugin_file ] ) ) {
+ return self::$dependencies[ $plugin_file ];
+ }
+
+ return array();
+ }
+
+ /**
+ * Gets a dependent plugin's filepath.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slug The dependent plugin's slug.
+ * @return string|false The dependent plugin's filepath, relative to the plugins directory,
+ * or false if the plugin has no dependencies.
+ */
+ public static function get_dependent_filepath( $slug ) {
+ $filepath = array_search( $slug, self::$dependent_slugs, true );
+
+ return $filepath ? $filepath : false;
+ }
+
+ /**
+ * Determines whether the plugin has unmet dependencies.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return bool Whether the plugin has unmet dependencies.
+ */
+ public static function has_unmet_dependencies( $plugin_file ) {
+ if ( ! isset( self::$dependencies[ $plugin_file ] ) ) {
+ return false;
+ }
+
+ require_once ABSPATH . '/wp-admin/includes/plugin.php';
+
+ foreach ( self::$dependencies[ $plugin_file ] as $dependency ) {
+ $dependency_filepath = self::get_dependency_filepath( $dependency );
+
+ if ( false === $dependency_filepath || is_plugin_inactive( $dependency_filepath ) ) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Determines whether the plugin has a circular dependency.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return bool Whether the plugin has a circular dependency.
+ */
+ public static function has_circular_dependency( $plugin_file ) {
+ if ( ! is_array( self::$circular_dependencies_slugs ) ) {
+ self::get_circular_dependencies();
+ }
+
+ if ( ! empty( self::$circular_dependencies_slugs ) ) {
+ $slug = self::convert_to_slug( $plugin_file );
+
+ if ( in_array( $slug, self::$circular_dependencies_slugs, true ) ) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * Gets the names of plugins that require the plugin.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return array An array of dependent names.
+ */
+ public static function get_dependent_names( $plugin_file ) {
+ $dependent_names = array();
+ $plugins = self::get_plugins();
+ $slug = self::convert_to_slug( $plugin_file );
+
+ foreach ( self::get_dependents( $slug ) as $dependent ) {
+ $dependent_names[ $dependent ] = $plugins[ $dependent ]['Name'];
+ }
+ sort( $dependent_names );
+
+ return $dependent_names;
+ }
+
+ /**
+ * Gets the names of plugins required by the plugin.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The dependent plugin's filepath, relative to the plugins directory.
+ * @return array An array of dependency names.
+ */
+ public static function get_dependency_names( $plugin_file ) {
+ $dependency_api_data = self::get_dependency_api_data();
+ $dependencies = self::get_dependencies( $plugin_file );
+ $plugins = self::get_plugins();
+
+ $dependency_names = array();
+ foreach ( $dependencies as $dependency ) {
+ // Use the name if it's available, otherwise fall back to the slug.
+ if ( isset( $dependency_api_data[ $dependency ]['name'] ) ) {
+ $name = $dependency_api_data[ $dependency ]['name'];
+ } else {
+ $dependency_filepath = self::get_dependency_filepath( $dependency );
+ if ( false !== $dependency_filepath ) {
+ $name = $plugins[ $dependency_filepath ]['Name'];
+ } else {
+ $name = $dependency;
+ }
+ }
+
+ $dependency_names[ $dependency ] = $name;
+ }
+
+ return $dependency_names;
+ }
+
+ /**
+ * Gets the filepath for a dependency, relative to the plugin's directory.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slug The dependency's slug.
+ * @return string|false If installed, the dependency's filepath relative to the plugins directory, otherwise false.
+ */
+ public static function get_dependency_filepath( $slug ) {
+ $dependency_filepaths = self::get_dependency_filepaths();
+
+ if ( ! isset( $dependency_filepaths[ $slug ] ) ) {
+ return false;
+ }
+
+ return $dependency_filepaths[ $slug ];
+ }
+
+ /**
+ * Returns API data for the dependency.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slug The dependency's slug.
+ * @return array|false The dependency's API data on success, otherwise false.
+ */
+ public static function get_dependency_data( $slug ) {
+ $dependency_api_data = self::get_dependency_api_data();
+
+ if ( isset( $dependency_api_data[ $slug ] ) ) {
+ return $dependency_api_data[ $slug ];
+ }
+
+ return false;
+ }
+
+ /**
+ * Displays an admin notice if dependencies are not installed.
+ *
+ * @since 6.5.0
+ */
+ public static function display_admin_notice_for_unmet_dependencies() {
+ if ( in_array( false, self::get_dependency_filepaths(), true ) ) {
+ $error_message = __( 'Some required plugins are missing or inactive.' );
+
+ if ( is_multisite() ) {
+ if ( current_user_can( 'manage_network_plugins' ) ) {
+ $error_message .= ' ' . sprintf(
+ /* translators: %s: Link to the network plugins page. */
+ __( '<a href="%s">Manage plugins</a>.' ),
+ esc_url( network_admin_url( 'plugins.php' ) )
+ );
+ } else {
+ $error_message .= ' ' . __( 'Please contact your network administrator.' );
+ }
+ } elseif ( 'plugins' !== get_current_screen()->base ) {
+ $error_message .= ' ' . sprintf(
+ /* translators: %s: Link to the plugins page. */
+ __( '<a href="%s">Manage plugins</a>.' ),
+ esc_url( admin_url( 'plugins.php' ) )
+ );
+ }
+
+ wp_admin_notice(
+ $error_message,
+ array(
+ 'type' => 'warning',
+ )
+ );
+ }
+ }
+
+ /**
+ * Displays an admin notice if circular dependencies are installed.
+ *
+ * @since 6.5.0
+ */
+ public static function display_admin_notice_for_circular_dependencies() {
+ $circular_dependencies = self::get_circular_dependencies();
+ if ( ! empty( $circular_dependencies ) && count( $circular_dependencies ) > 1 ) {
+ $circular_dependencies = array_unique( $circular_dependencies, SORT_REGULAR );
+ $plugins = self::get_plugins();
+ $plugin_dirnames = self::get_plugin_dirnames();
+
+ // Build output lines.
+ $circular_dependency_lines = '';
+ foreach ( $circular_dependencies as $circular_dependency ) {
+ $first_filepath = $plugin_dirnames[ $circular_dependency[0] ];
+ $second_filepath = $plugin_dirnames[ $circular_dependency[1] ];
+ $circular_dependency_lines .= sprintf(
+ /* translators: 1: First plugin name, 2: Second plugin name. */
+ '<li>' . _x( '%1$s requires %2$s', 'The first plugin requires the second plugin.' ) . '</li>',
+ '<strong>' . esc_html( $plugins[ $first_filepath ]['Name'] ) . '</strong>',
+ '<strong>' . esc_html( $plugins[ $second_filepath ]['Name'] ) . '</strong>'
+ );
+ }
+
+ wp_admin_notice(
+ sprintf(
+ '<p>%1$s</p><ul>%2$s</ul><p>%3$s</p>',
+ __( 'These plugins cannot be activated because their requirements are invalid.' ),
+ $circular_dependency_lines,
+ __( 'Please contact the plugin authors for more information.' )
+ ),
+ array(
+ 'type' => 'warning',
+ 'paragraph_wrap' => false,
+ )
+ );
+ }
+ }
+
+ /**
+ * Checks plugin dependencies after a plugin is installed via AJAX.
+ *
+ * @since 6.5.0
+ */
+ public static function check_plugin_dependencies_during_ajax() {
+ check_ajax_referer( 'updates' );
+
+ if ( empty( $_POST['slug'] ) ) {
+ wp_send_json_error(
+ array(
+ 'slug' => '',
+ 'pluginName' => '',
+ 'errorCode' => 'no_plugin_specified',
+ 'errorMessage' => __( 'No plugin specified.' ),
+ )
+ );
+ }
+
+ $slug = sanitize_key( wp_unslash( $_POST['slug'] ) );
+ $status = array( 'slug' => $slug );
+
+ self::get_plugins();
+ self::get_plugin_dirnames();
+
+ if ( ! isset( self::$plugin_dirnames[ $slug ] ) ) {
+ $status['errorCode'] = 'plugin_not_installed';
+ $status['errorMessage'] = __( 'The plugin is not installed.' );
+ wp_send_json_error( $status );
+ }
+
+ $plugin_file = self::$plugin_dirnames[ $slug ];
+ $status['pluginName'] = self::$plugins[ $plugin_file ]['Name'];
+ $status['plugin'] = $plugin_file;
+
+ if ( current_user_can( 'activate_plugin', $plugin_file ) && is_plugin_inactive( $plugin_file ) ) {
+ $status['activateUrl'] = add_query_arg(
+ array(
+ '_wpnonce' => wp_create_nonce( 'activate-plugin_' . $plugin_file ),
+ 'action' => 'activate',
+ 'plugin' => $plugin_file,
+ ),
+ is_multisite() ? network_admin_url( 'plugins.php' ) : admin_url( 'plugins.php' )
+ );
+ }
+
+ if ( is_multisite() && current_user_can( 'manage_network_plugins' ) ) {
+ $status['activateUrl'] = add_query_arg( array( 'networkwide' => 1 ), $status['activateUrl'] );
+ }
+
+ self::initialize();
+ $dependencies = self::get_dependencies( $plugin_file );
+ if ( empty( $dependencies ) ) {
+ $status['message'] = __( 'The plugin has no required plugins.' );
+ wp_send_json_success( $status );
+ }
+
+ require_once ABSPATH . '/wp-admin/includes/plugin.php';
+
+ $inactive_dependencies = array();
+ foreach ( $dependencies as $dependency ) {
+ if ( false === self::$plugin_dirnames[ $dependency ] || is_plugin_inactive( self::$plugin_dirnames[ $dependency ] ) ) {
+ $inactive_dependencies[] = $dependency;
+ }
+ }
+
+ if ( ! empty( $inactive_dependencies ) ) {
+ $inactive_dependency_names = array_map(
+ function ( $dependency ) {
+ if ( isset( self::$dependency_api_data[ $dependency ]['Name'] ) ) {
+ $inactive_dependency_name = self::$dependency_api_data[ $dependency ]['Name'];
+ } else {
+ $inactive_dependency_name = $dependency;
+ }
+ return $inactive_dependency_name;
+ },
+ $inactive_dependencies
+ );
+
+ $status['errorCode'] = 'inactive_dependencies';
+ $status['errorMessage'] = sprintf(
+ /* translators: %s: A list of inactive dependency plugin names. */
+ __( 'The following plugins must be activated first: %s.' ),
+ implode( ', ', $inactive_dependency_names )
+ );
+ $status['errorData'] = array_combine( $inactive_dependencies, $inactive_dependency_names );
+
+ wp_send_json_error( $status );
+ }
+
+ $status['message'] = __( 'All required plugins are installed and activated.' );
+ wp_send_json_success( $status );
+ }
+
+ /**
+ * Gets data for installed plugins.
+ *
+ * @since 6.5.0
+ *
+ * @return array An array of plugin data.
+ */
+ protected static function get_plugins() {
+ if ( is_array( self::$plugins ) ) {
+ return self::$plugins;
+ }
+
+ require_once ABSPATH . '/wp-admin/includes/plugin.php';
+ self::$plugins = get_plugins();
+
+ return self::$plugins;
+ }
+
+ /**
+ * Reads and stores dependency slugs from a plugin's 'Requires Plugins' header.
+ *
+ * @since 6.5.0
+ */
+ protected static function read_dependencies_from_plugin_headers() {
+ self::$dependencies = array();
+ self::$dependency_slugs = array();
+ self::$dependent_slugs = array();
+ $plugins = self::get_plugins();
+ foreach ( $plugins as $plugin => $header ) {
+ if ( '' === $header['RequiresPlugins'] ) {
+ continue;
+ }
+
+ $dependency_slugs = self::sanitize_dependency_slugs( $header['RequiresPlugins'] );
+ self::$dependencies[ $plugin ] = $dependency_slugs;
+ self::$dependency_slugs = array_merge( self::$dependency_slugs, $dependency_slugs );
+
+ $dependent_slug = self::convert_to_slug( $plugin );
+ self::$dependent_slugs[ $plugin ] = $dependent_slug;
+ }
+ self::$dependency_slugs = array_unique( self::$dependency_slugs );
+ }
+
+ /**
+ * Sanitizes slugs.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slugs A comma-separated string of plugin dependency slugs.
+ * @return array An array of sanitized plugin dependency slugs.
+ */
+ protected static function sanitize_dependency_slugs( $slugs ) {
+ $sanitized_slugs = array();
+ $slugs = explode( ',', $slugs );
+
+ foreach ( $slugs as $slug ) {
+ $slug = trim( $slug );
+
+ /**
+ * Filters a plugin dependency's slug before matching to
+ * the WordPress.org slug format.
+ *
+ * Can be used to switch between free and premium plugin slugs, for example.
+ *
+ * @since 6.5.0
+ *
+ * @param string $slug The slug.
+ */
+ $slug = apply_filters( 'wp_plugin_dependencies_slug', $slug );
+
+ // Match to WordPress.org slug format.
+ if ( preg_match( '/^[a-z0-9]+(-[a-z0-9]+)*$/mu', $slug ) ) {
+ $sanitized_slugs[] = $slug;
+ }
+ }
+ $sanitized_slugs = array_unique( $sanitized_slugs );
+ sort( $sanitized_slugs );
+
+ return $sanitized_slugs;
+ }
+
+ /**
+ * Gets the filepath of installed dependencies.
+ * If a dependency is not installed, the filepath defaults to false.
+ *
+ * @since 6.5.0
+ *
+ * @return array An array of install dependencies filepaths, relative to the plugins directory.
+ */
+ protected static function get_dependency_filepaths() {
+ if ( is_array( self::$dependency_filepaths ) ) {
+ return self::$dependency_filepaths;
+ }
+
+ if ( null === self::$dependency_slugs ) {
+ return array();
+ }
+
+ self::$dependency_filepaths = array();
+
+ $plugin_dirnames = self::get_plugin_dirnames();
+ foreach ( self::$dependency_slugs as $slug ) {
+ if ( isset( $plugin_dirnames[ $slug ] ) ) {
+ self::$dependency_filepaths[ $slug ] = $plugin_dirnames[ $slug ];
+ continue;
+ }
+
+ self::$dependency_filepaths[ $slug ] = false;
+ }
+
+ return self::$dependency_filepaths;
+ }
+
+ /**
+ * Retrieves and stores dependency plugin data from the WordPress.org Plugin API.
+ *
+ * @since 6.5.0
+ *
+ * @global string $pagenow The filename of the current screen.
+ *
+ * @return array|void An array of dependency API data, or void on early exit.
+ */
+ protected static function get_dependency_api_data() {
+ global $pagenow;
+
+ if ( ! is_admin() || ( 'plugins.php' !== $pagenow && 'plugin-install.php' !== $pagenow ) ) {
+ return;
+ }
+
+ if ( is_array( self::$dependency_api_data ) ) {
+ return self::$dependency_api_data;
+ }
+
+ $plugins = self::get_plugins();
+ self::$dependency_api_data = (array) get_site_transient( 'wp_plugin_dependencies_plugin_data' );
+ foreach ( self::$dependency_slugs as $slug ) {
+ // Set transient for individual data, remove from self::$dependency_api_data if transient expired.
+ if ( ! get_site_transient( "wp_plugin_dependencies_plugin_timeout_{$slug}" ) ) {
+ unset( self::$dependency_api_data[ $slug ] );
+ set_site_transient( "wp_plugin_dependencies_plugin_timeout_{$slug}", true, 12 * HOUR_IN_SECONDS );
+ }
+
+ if ( isset( self::$dependency_api_data[ $slug ] ) ) {
+ if ( false === self::$dependency_api_data[ $slug ] ) {
+ $dependency_file = self::get_dependency_filepath( $slug );
+
+ if ( false === $dependency_file ) {
+ self::$dependency_api_data[ $slug ] = array( 'Name' => $slug );
+ } else {
+ self::$dependency_api_data[ $slug ] = array( 'Name' => $plugins[ $dependency_file ]['Name'] );
+ }
+ continue;
+ }
+
+ // Don't hit the Plugin API if data exists.
+ if ( ! empty( self::$dependency_api_data[ $slug ]['last_updated'] ) ) {
+ continue;
+ }
+ }
+
+ if ( ! function_exists( 'plugins_api' ) ) {
+ require_once ABSPATH . 'wp-admin/includes/plugin-install.php';
+ }
+
+ $information = plugins_api(
+ 'plugin_information',
+ array(
+ 'slug' => $slug,
+ 'fields' => array(
+ 'short_description' => true,
+ 'icons' => true,
+ ),
+ )
+ );
+
+ if ( is_wp_error( $information ) ) {
+ continue;
+ }
+
+ self::$dependency_api_data[ $slug ] = (array) $information;
+ // plugins_api() returns 'name' not 'Name'.
+ self::$dependency_api_data[ $slug ]['Name'] = self::$dependency_api_data[ $slug ]['name'];
+ set_site_transient( 'wp_plugin_dependencies_plugin_data', self::$dependency_api_data, 0 );
+ }
+
+ // Remove from self::$dependency_api_data if slug no longer a dependency.
+ $differences = array_diff( array_keys( self::$dependency_api_data ), self::$dependency_slugs );
+ foreach ( $differences as $difference ) {
+ unset( self::$dependency_api_data[ $difference ] );
+ }
+
+ ksort( self::$dependency_api_data );
+ // Remove empty elements.
+ self::$dependency_api_data = array_filter( self::$dependency_api_data );
+ set_site_transient( 'wp_plugin_dependencies_plugin_data', self::$dependency_api_data, 0 );
+
+ return self::$dependency_api_data;
+ }
+
+ /**
+ * Gets plugin directory names.
+ *
+ * @since 6.5.0
+ *
+ * @return array An array of plugin directory names.
+ */
+ protected static function get_plugin_dirnames() {
+ if ( is_array( self::$plugin_dirnames ) ) {
+ return self::$plugin_dirnames;
+ }
+
+ self::$plugin_dirnames = array();
+
+ $plugin_files = array_keys( self::get_plugins() );
+ foreach ( $plugin_files as $plugin_file ) {
+ $slug = self::convert_to_slug( $plugin_file );
+ self::$plugin_dirnames[ $slug ] = $plugin_file;
+ }
+
+ return self::$plugin_dirnames;
+ }
+
+ /**
+ * Gets circular dependency data.
+ *
+ * @since 6.5.0
+ *
+ * @return array[] An array of circular dependency pairings.
+ */
+ protected static function get_circular_dependencies() {
+ if ( is_array( self::$circular_dependencies_pairs ) ) {
+ return self::$circular_dependencies_pairs;
+ }
+
+ if ( null === self::$dependencies ) {
+ return array();
+ }
+
+ self::$circular_dependencies_slugs = array();
+
+ self::$circular_dependencies_pairs = array();
+ foreach ( self::$dependencies as $dependent => $dependencies ) {
+ /*
+ * $dependent is in 'a/a.php' format. Dependencies are stored as slugs, i.e. 'a'.
+ *
+ * Convert $dependent to slug format for checking.
+ */
+ $dependent_slug = self::convert_to_slug( $dependent );
+
+ self::$circular_dependencies_pairs = array_merge(
+ self::$circular_dependencies_pairs,
+ self::check_for_circular_dependencies( array( $dependent_slug ), $dependencies )
+ );
+ }
+
+ return self::$circular_dependencies_pairs;
+ }
+
+ /**
+ * Checks for circular dependencies.
+ *
+ * @since 6.5.0
+ *
+ * @param array $dependents Array of dependent plugins.
+ * @param array $dependencies Array of plugins dependencies.
+ * @return array A circular dependency pairing, or an empty array if none exists.
+ */
+ protected static function check_for_circular_dependencies( $dependents, $dependencies ) {
+ $circular_dependencies_pairs = array();
+
+ // Check for a self-dependency.
+ $dependents_location_in_its_own_dependencies = array_intersect( $dependents, $dependencies );
+ if ( ! empty( $dependents_location_in_its_own_dependencies ) ) {
+ foreach ( $dependents_location_in_its_own_dependencies as $self_dependency ) {
+ self::$circular_dependencies_slugs[] = $self_dependency;
+ $circular_dependencies_pairs[] = array( $self_dependency, $self_dependency );
+
+ // No need to check for itself again.
+ unset( $dependencies[ array_search( $self_dependency, $dependencies, true ) ] );
+ }
+ }
+
+ /*
+ * Check each dependency to see:
+ * 1. If it has dependencies.
+ * 2. If its list of dependencies includes one of its own dependents.
+ */
+ foreach ( $dependencies as $dependency ) {
+ // Check if the dependency is also a dependent.
+ $dependency_location_in_dependents = array_search( $dependency, self::$dependent_slugs, true );
+
+ if ( false !== $dependency_location_in_dependents ) {
+ $dependencies_of_the_dependency = self::$dependencies[ $dependency_location_in_dependents ];
+
+ foreach ( $dependents as $dependent ) {
+ // Check if its dependencies includes one of its own dependents.
+ $dependent_location_in_dependency_dependencies = array_search(
+ $dependent,
+ $dependencies_of_the_dependency,
+ true
+ );
+
+ if ( false !== $dependent_location_in_dependency_dependencies ) {
+ self::$circular_dependencies_slugs[] = $dependent;
+ self::$circular_dependencies_slugs[] = $dependency;
+ $circular_dependencies_pairs[] = array( $dependent, $dependency );
+
+ // Remove the dependent from its dependency's dependencies.
+ unset( $dependencies_of_the_dependency[ $dependent_location_in_dependency_dependencies ] );
+ }
+ }
+
+ $dependents[] = $dependency;
+
+ /*
+ * Now check the dependencies of the dependency's dependencies for the dependent.
+ *
+ * Yes, that does make sense.
+ */
+ $circular_dependencies_pairs = array_merge(
+ $circular_dependencies_pairs,
+ self::check_for_circular_dependencies( $dependents, array_unique( $dependencies_of_the_dependency ) )
+ );
+ }
+ }
+
+ return $circular_dependencies_pairs;
+ }
+
+ /**
+ * Converts a plugin filepath to a slug.
+ *
+ * @since 6.5.0
+ *
+ * @param string $plugin_file The plugin's filepath, relative to the plugins directory.
+ * @return string The plugin's slug.
+ */
+ protected static function convert_to_slug( $plugin_file ) {
+ if ( 'hello.php' === $plugin_file ) {
+ return 'hello-dolly';
+ }
+ return str_contains( $plugin_file, '/' ) ? dirname( $plugin_file ) : str_replace( '.php', '', $plugin_file );
+ }
+}