Add tests

phpstan.neon.dist

@@ -2,6 +2,7 @@ parameters:
     level: 8
     paths:
         - src
+        - tests/StaticAnalysis
 
     ignoreErrors:
         -

psalm.xml.dist

@@ -9,6 +9,7 @@
 >
     <projectFiles>
         <directory name="src" />
+        <directory name="tests/StaticAnalysis" />
         <ignoreFiles>
             <directory name="vendor" />
             <directory name="src/Expr"/>

tests/StaticAnalysis/CustomCollection.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Common\Collections\StaticAnalysis;
+
+use Closure;
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+
+/**
+ * @phpstan-template TKey of array-key
+ * @phpstan-template T of object
+ * @phpstan-implements Collection<TKey, T>
+ */
+abstract class CustomCollection implements Collection
+{
+    /** @var ArrayCollection<TKey, T> */
+    private ArrayCollection $collection;
+
+    /** @param ArrayCollection<TKey, T> $arrayCollection */
+    public function __construct(ArrayCollection $arrayCollection)
+    {
+        $this->collection = $arrayCollection;
+    }
+
+    /**
+     * @psalm-param Closure(T, TKey):bool $p
+     *
+     * @return Collection<TKey, T>
+     */
+    public function filter(Closure $p)
+    {
+        return $this->collection->filter($p);
+    }
+
+    /**
+     * @psalm-param Closure(TKey, T):bool $p
+     *
+     * @psalm-return array{0: Collection<TKey, T>, 1: Collection<TKey, T>}
+     */
+    public function partition(Closure $p)
+    {
+        return $this->collection->partition($p);
+    }
+}