Regression test

Closes phpstan/phpstan#8008

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1049,6 +1049,7 @@ public function dataFileAsserts(): iterable
 		}
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-offset-unset.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8008.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-8008.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace Bug8008;
+
+use function \PHPStan\Testing\assertType;
+
+/**
+ * @template TValue
+ */
+class Collection
+{
+	/**
+	 * @param array<TValue> $items
+	 */
+	public function __construct(
+		public array $items,
+	) {
+	}
+
+	/**
+	 * @return array<TValue>
+	 */
+	public function all() {
+		return $this->items;
+	}
+}
+
+/**
+ * @template TValue of object
+ *
+ * @mixin Collection<TValue>
+ */
+class Paginator
+{
+	/**
+	 * @var Collection<TValue>
+	 */
+	public Collection $collection;
+
+	/**
+	 * @param array<TValue> $items
+	 */
+	public function __construct(public array $items)
+	{
+		$this->collection = new Collection($items);
+	}
+}
+
+class MyObject {}
+
+
+function (): void {
+	$paginator = new Paginator([new MyObject()]);
+
+	assertType('Bug8008\Paginator<Bug8008\MyObject>', $paginator);
+	assertType('array<Bug8008\MyObject>', $paginator->items);
+	assertType('Bug8008\Collection<Bug8008\MyObject>', $paginator->collection);
+	assertType('array<Bug8008\MyObject>', $paginator->collection->items);
+
+	assertType('array<Bug8008\MyObject>', $paginator->all());
+};