Force the use of only one "test-tenant" in phpunit tests

TestCase.php

<?php

namespace Tests;

use Hyn\Tenancy\Contracts\Repositories\HostnameRepository;
use Hyn\Tenancy\Contracts\Repositories\WebsiteRepository;
use Hyn\Tenancy\Environment;
use Hyn\Tenancy\Models\Hostname;
use Hyn\Tenancy\Models\Website;
use Illuminate\Foundation\Testing\DatabaseTransactions;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Illuminate\Foundation\Testing\TestCase as BaseTestCase;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

abstract class TestCase extends BaseTestCase
{
    use CreatesApplication;
//    use RefreshDatabase;
//    use DatabaseTransactions;

    protected static $is_tenant_created = false;

    const WEBSITE_UUID = 'test-tenant';
    const DOMAIN = 'example.com';
    const FQDN = self::WEBSITE_UUID . '.' . self::DOMAIN;

    protected function setUp()
    {
        parent::setUp();

        if (!static::$is_tenant_created) {
            if (!Hostname::where('fqdn', '=', self::FQDN)->first()) {
                $this->createNewTenant();
            }
            static::$is_tenant_created = true;
        }

        $this->switchActiveTenant();

        // TODO: Would be nice to be able to use the RefreshDatabase trait instead of this.
        $this->truncateAllTables();
    }

    protected function truncateAllTables(): void
    {
        $table_names = Schema::getConnection()->getDoctrineSchemaManager()->listTableNames();

        DB::statement('SET FOREIGN_KEY_CHECKS=0;');
        foreach ($table_names as $table_name) {
            if ($table_name == 'migrations') {
                continue;
            }
            DB::table($table_name)->truncate();
        }
        DB::statement('SET FOREIGN_KEY_CHECKS=1;');
    }

    protected function createNewTenant(): void
    {
        $website = $this->createTenantWebsite();
        $this->createTenantHostname($website);
    }

    /**
     * @return Website
     */
    protected function createTenantWebsite(): Website
    {
        $website = new Website;
        $website->uuid = self::WEBSITE_UUID;
        app(WebsiteRepository::class)->create($website);

        return $website;
    }

    /**
     * @param $website
     */
    protected function createTenantHostname($website): void
    {
        $hostname = new Hostname;
        $hostname->fqdn = self::FQDN;
        app(HostnameRepository::class)->attach($hostname, $website);
    }

    protected function switchActiveTenant(): void
    {
        $hostname = Hostname::where('fqdn', '=', self::FQDN)->firstOrFail();

        $environment = app(Environment::class);
        $environment->hostname($hostname);
    }
}