wp-discourse/tests/phpunit/helpers/multisite.php

<?php
/**
 * Class \Test\Multisite
 *
 * @package WPDiscourse
 */

namespace WPDiscourse\Test;

/**
 * Multisite methods for WPDiscourse unit tests
 */
trait Multisite {

    /**
     * Setup multisite tests
     */
    public function setUp(): void {
		parent::setUp();
		$this->create_topic_blog_table();
    }

    /**
     * Teardown multisite tests
     */
    public function tearDown(): void {
		parent::tearDown();
		$this->clear_topic_blog_table();
    }

    /**
     * Create topic_blog_table if it doesn't exist.
     */
    protected function create_topic_blog_table() {
		global $wpdb;

		$table = $wpdb->base_prefix . 'wpdc_topic_blog';
		$sql   = sprintf(
            'CREATE TABLE %s (
            topic_id mediumint(9) NOT NULL,
            blog_id mediumint(9) NOT NULL,
            PRIMARY KEY  (topic_id)
          ) %s;',
            $table,
            $wpdb->get_charset_collate()
		);

		require_once ABSPATH . 'wp-admin/includes/upgrade.php';
		maybe_create_table( $table, $sql );
    }

    /**
     * Clear topic_blog_table.
     */
    protected function clear_topic_blog_table() {
		global $wpdb;
		$table  = $wpdb->base_prefix . 'wpdc_topic_blog';
		$result = $wpdb->query( "TRUNCATE TABLE $table" );
    }

    /**
     * Switch to blog for discourse topic.
     */
    protected function switch_to_blog_for_topic( $topic_id ) {
		global $wpdb;
		$table_name = $wpdb->base_prefix . 'wpdc_topic_blog';
		$query      = "SELECT blog_id FROM $table_name WHERE topic_id = %d";
		$blog_id    = $wpdb->get_var( $wpdb->prepare( $query, $topic_id ) );
		switch_to_blog( $blog_id );
    }
}