Testing Laravel apps with multiple domains

When testing Laravel applications that use multiple domains tests get tricky. Imagine an application with the following structure:

• API: api.domain.com
• Backend: manage.domain.com
• Client domains: client1domain.com,client2domain.com, etc..

Route::domain(config('app.domains.api'))->group(function() {
  Route::get('/', 'Api\ApiIndexController@index')->as('api.index');
});

Route::domain(config('app.domains.backend'))->group(function() {
  Route::get('/', 'Backend\BackendIndexController@index')->as('backend.index');
});

// fallback to client domains
Route::group(function() {
  Route::get('/', 'Sites\SitesIndexController@index')->as('site.index');
});

Now let’s see how we would go about testing the routes within each domain.

namespace Tests\Feature\Api;

use Tests\TestCase;

class ApiDomainTest extends TestCase
{
    function setUp(): void
    {
        parent::setUp();
        config(['app.url' => "http://${config('app.domains.api')}"]);
    }

    public function testApiIndex()
    {
        $response = $this->json('GET', route('api.index'));
        $response->assertStatus(200)->assertSeeText('API index.');
    }
}

namespace Tests\Feature\Backend;

use Tests\TestCase;

class BackendDomainTest extends TestCase
{
    function setUp(): void
    {
        parent::setUp();
        config(['app.url' => "https://${config('app.domains.backend')}"]);
    }

    public function testBackendApiIndex()
    {
        $response = $this->json('GET', route('backend.index'));
        $response->assertStatus(200)->assertSeeText('Backend index.');
    }
}

namespace Tests\Feature\Site;

use Tests\TestCase;

class SiteDomainsTest extends TestCase
{
    public function testClient1SiteIndex()
    {
        config(['app.url' => "http://clientdomain1.com"]);
        $response = $this->json('GET', route('site.index'));
        $response->assertStatus(200)->assertSeeText('This is client site 1 index.');
    }

     public function testClient1SiteIndex()
    {
        config(['app.url' => "http://clientdomain2.com"]);
        $response = $this->json('GET', route('site.index'));
        $response->assertStatus(200)->assertSeeText('This is client site 2 index.');
    }
}