• File: class-wp-plugin-dependencies.php
  • Full Path: /home/u505525515/domains/medineeestates.com/public_html/wp-includes/class-wp-plugin-dependencies.php
  • Date Modified: 05/25/2026 6:29 AM
  • File size: 24.59 KB
  • MIME-type: text/x-php
  • Charset: utf-8
<?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( $plugin_file ) {
        return self::$dependencies[ $plugin_file ] ?? 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();
        return $dependency_api_data[ $slug ] ?? 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 );
    }
}