test PromoteUserToAdmin use case

backend/tests/Unit/User/UseCases/PromoteUserToAdminTest.php

@@ -0,0 +1,94 @@
+<?php
+
+namespace Tests\Unit\User\UseCases;
+
+use App\Exceptions\BadRequestException;
+use App\Exceptions\ForbiddenException;
+use App\Shared\ValueObject\EmailAddress;
+use App\User\CreateUserDto;
+use App\User\UseCases\PromoteUserToAdmin\PromoteUserToAdmin;
+use App\User\UseCases\PromoteUserToAdmin\PromoteUserToAdminRequest;
+use DomainException;
+use Tests\Fakes\FakeUserRepository;
+use Tests\TestCase;
+
+class PromoteUserToAdminTest extends TestCase
+{
+    private FakeUserRepository $userRepo;
+
+    private PromoteUserToAdmin $useCase;
+
+    protected function setUp(): void
+    {
+        $this->userRepo = new FakeUserRepository;
+        $this->useCase = new PromoteUserToAdmin($this->userRepo);
+    }
+
+    private function seedUser(bool $isAdmin): int
+    {
+        $user = $this->userRepo->create(new CreateUserDto(
+            email: new EmailAddress('user@example.com'),
+            displayName: 'user',
+            passwordHash: 'h',
+            isAdmin: $isAdmin,
+            emailConfirmedAt: null,
+        ));
+
+        return $user->getId();
+    }
+
+    public function test_non_admin_requester_throws_forbidden(): void
+    {
+        $userId = $this->seedUser(false);
+
+        $this->expectException(ForbiddenException::class);
+        $this->useCase->execute(new PromoteUserToAdminRequest(
+            targetUserId: $userId,
+            requesterIsAdmin: false,
+        ));
+    }
+
+    public function test_zero_target_id_throws_bad_request(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->useCase->execute(new PromoteUserToAdminRequest(
+            targetUserId: 0,
+            requesterIsAdmin: true,
+        ));
+    }
+
+    public function test_unknown_user_throws_domain_exception(): void
+    {
+        $this->expectException(DomainException::class);
+        $this->useCase->execute(new PromoteUserToAdminRequest(
+            targetUserId: 999,
+            requesterIsAdmin: true,
+        ));
+    }
+
+    public function test_admin_promotes_target(): void
+    {
+        $userId = $this->seedUser(false);
+
+        $this->useCase->execute(new PromoteUserToAdminRequest(
+            targetUserId: $userId,
+            requesterIsAdmin: true,
+        ));
+
+        $reloaded = $this->userRepo->find($userId);
+        $this->assertTrue($reloaded->isAdmin());
+    }
+
+    public function test_already_admin_is_idempotent(): void
+    {
+        $userId = $this->seedUser(true);
+
+        $this->useCase->execute(new PromoteUserToAdminRequest(
+            targetUserId: $userId,
+            requesterIsAdmin: true,
+        ));
+
+        $reloaded = $this->userRepo->find($userId);
+        $this->assertTrue($reloaded->isAdmin());
+    }
+}