feat: add the booking domain layer

tests/Entity/UserTest.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Entity;
+
+use App\Entity\User;
+use PHPUnit\Framework\TestCase;
+
+class UserTest extends TestCase
+{
+    public function testEveryUserGetsRoleUserWithoutItBeingStored(): void
+    {
+        self::assertSame(['ROLE_USER'], (new User('[email protected]', 'A'))->getRoles());
+    }
+
+    public function testRoleUserIsNotDuplicatedWhenAlreadyGranted(): void
+    {
+        $user = new User('[email protected]', 'A');
+        $user->setRoles(['ROLE_USER', 'ROLE_EMPLOYEE']);
+
+        self::assertSame(['ROLE_USER', 'ROLE_EMPLOYEE'], $user->getRoles());
+    }
+
+    public function testTheEmailIsTheSecurityIdentifier(): void
+    {
+        self::assertSame('[email protected]', (new User('[email protected]', 'A'))->getUserIdentifier());
+    }
+}