Include a uninstall routine

[TheCrowned]

Right now, the plugin does not uninstall itself at all. We may want to create a uninstall.php file that removes all plugin records from database to avoid leaving it cluttered with potentially unwanted data.

[TheCrowned]

Right now I am using this WP_CLI command to clear the database from all non-necessary CAP entries. Useful for testing, it basically reverts wp co-authors-plus create-guest-authors and wp co-authors-plus create-terms-for-posts. Nor sure we want it in the repo code though.

/**
 * Subcommand to delete guest authors based on users.
 *
 * @subcommand delete-linked-guest-authors
 */
public function delete_linked_guest_authors( $args, $assoc_args ) {
    global $coauthors_plus;

    WP_CLI::confirm( 'Are you sure you want to delete author terms for all users having a linked account? This includes posts and author terms.' );

    $defaults = array(
        // There are no arguments at this time
    );
    $this->args = wp_parse_args( $assoc_args, $defaults );

    $users = get_users();
    $created = 0;
    $skipped = 0;
    $progress = \WP_CLI\Utils\make_progress_bar( 'Processing guest authors...', count ( $users ) );
    foreach ( $users as $user ) {

        $guest_author = $coauthors_plus->guest_authors->get_guest_author_by( 'linked_account', $user->data->user_login );

        if ( ! empty( $guest_author ) ) {
            $coauthors_plus->guest_authors->delete( $guest_author->ID );
        }           
        $progress->tick();
    }
    $progress->finish();
    WP_CLI::success( sprintf( 'All done! Processed %d users.', count( $users ) ) );
}