Created unit tests for new Domain-related elements

module/Rest/test/Action/Domain/ListDomainsActionTest.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ShlinkioTest\Shlink\Rest\Action\Domain;
+
+use Laminas\Diactoros\Response\JsonResponse;
+use Laminas\Diactoros\ServerRequestFactory;
+use PHPUnit\Framework\TestCase;
+use Prophecy\Prophecy\ObjectProphecy;
+use Shlinkio\Shlink\Core\Domain\DomainServiceInterface;
+use Shlinkio\Shlink\Core\Entity\Domain;
+use Shlinkio\Shlink\Rest\Action\Domain\ListDomainsAction;
+
+class ListDomainsActionTest extends TestCase
+{
+    private ListDomainsAction $action;
+    private ObjectProphecy $domainService;
+
+    public function setUp(): void
+    {
+        $this->domainService = $this->prophesize(DomainServiceInterface::class);
+        $this->action = new ListDomainsAction($this->domainService->reveal(), 'foo.com');
+    }
+
+    /** @test */
+    public function domainsAreProperlyListed(): void
+    {
+        $listDomains = $this->domainService->listDomainsWithout('foo.com')->willReturn([
+            new Domain('bar.com'),
+            new Domain('baz.com'),
+        ]);
+
+        /** @var JsonResponse $resp */
+        $resp = $this->action->handle(ServerRequestFactory::fromGlobals());
+        $payload = $resp->getPayload();
+
+        self::assertEquals([
+            'domains' => [
+                'data' => [
+                    [
+                        'domain' => 'foo.com',
+                        'isDefault' => true,
+                    ],
+                    [
+                        'domain' => 'bar.com',
+                        'isDefault' => false,
+                    ],
+                    [
+                        'domain' => 'baz.com',
+                        'isDefault' => false,
+                    ],
+                ],
+            ],
+        ], $payload);
+        $listDomains->shouldHaveBeenCalledOnce();
+    }
+}