[TOOLS][TESTS] Add data fixtures, which populate the database with users used for testing

src/DataFixtures/NicknameFixtures.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace App\DataFixtures;
+
+use App\Entity\GSActor;
+use App\Entity\LocalGroup;
+use App\Entity\LocalUser;
+use App\Util\Nickname;
+use Doctrine\Bundle\FixturesBundle\Fixture;
+use Doctrine\Persistence\ObjectManager;
+
+class NicknameFixtures extends Fixture
+{
+    public function load(ObjectManager $manager)
+    {
+        foreach ([LocalUser::class => ['taken_user', 'setId'], LocalGroup::class => ['taken_group', 'setGroupId']] as $entity => [$nick, $method]) {
+            $actor = GSActor::create(['nickname' => $nick, 'normalized_nickname' => Nickname::normalize($nick, check_already_used: false)]);
+            $manager->persist($actor);
+            $ent = $entity::create(['nickname' => $nick]);
+            $ent->{$method}($actor->getId());
+            $manager->persist($ent);
+        }
+        $manager->flush();
+    }
+}