Add tests for counting previous talks

References #31

web/modules/custom/custom/src/Service/TalkCounter.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\custom\Service;
+
+use Carbon\Carbon;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\custom\Entity\Node\Talk;
+use Drupal\node\NodeInterface;
+use Drupal\paragraphs\ParagraphInterface;
+use Illuminate\Support\Collection;
+
+final class TalkCounter {
+
+  private EntityStorageInterface $nodeStorage;
+
+  public function __construct(EntityTypeManagerInterface $entityTypeManager) {
+    $this->nodeStorage = $entityTypeManager->getStorage('node');
+  }
+
+  public function getCount(): int {
+    $today = Carbon::today()->format('Y-m-d H:i:s');
+
+    return $this->getTalks()
+      ->flatMap->getEvents()
+      ->filter(fn(ParagraphInterface $event) => $event->get('field_date')->getString() <= $today)
+      ->count();
+  }
+
+  private function getTalks(): Collection {
+    $talks = $this->nodeStorage->loadByProperties([
+      'status' => NodeInterface::PUBLISHED,
+      'type' => 'talk',
+    ]);
+
+    return new Collection($talks);
+  }
+
+}