Add PHPStan

src/Presentation/Collection/Collection.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Presentation\Collection;
+
+use ArrayIterator;
+use Countable;
+use Iterator;
+use IteratorAggregate;
+
+/**
+ * @template TItem
+ */
+class Collection implements Countable, IteratorAggregate
+{
+    /**
+     * @param TItem[] $items
+     */
+    final public function __construct(protected array $items = [])
+    {
+    }
+
+    public function count(): int
+    {
+        return count($this->items);
+    }
+
+    public function filter(callable $callback): self
+    {
+        return new static(
+            array_filter(
+                array: $this->items,
+                callback: $callback,
+            )
+        );
+    }
+
+    public function getIterator(): Iterator
+    {
+        return new ArrayIterator($this->items);
+    }
+
+    /**
+     * @return TItem[]
+     */
+    public function toArray(): array
+    {
+        return $this->items;
+    }
+}