More SPL iterator stubs

Author: ondrejmirtes

stubs/iterable.stub

@@ -159,3 +159,32 @@ class RecursiveIteratorIterator
 	}
 
 }
+
+/**
+ * @template-covariant TKey
+ * @template-covariant TValue
+ *
+ * @template-extends Iterator<TKey, TValue>
+ */
+interface OuterIterator extends Iterator {
+    /**
+     * @return Iterator<TKey, TValue>
+     */
+    public function getInnerIterator();
+}
+
+/**
+ * @template-covariant TKey
+ * @template-covariant TValue
+ * @template TIterator as Traversable<TKey, TValue>
+ *
+ * @template-implements OuterIterator<TKey, TValue>
+ *
+ * @mixin TIterator
+ */
+class IteratorIterator implements OuterIterator {
+    /**
+     * @param TIterator $iterator
+     */
+    public function __construct(Traversable $iterator) {}
+}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -10956,6 +10956,11 @@ public function dataNestedGenericIncompleteConstructor(): array
 		return $this->gatherAssertTypes(__DIR__ . '/data/nested-generic-incomplete-constructor.php');
 	}
 
+	public function dataIteratorIterator(): array
+	{
+		return $this->gatherAssertTypes(__DIR__ . '/data/iterator-iterator.php');
+	}
+
 	/**
 	 * @param string $file
 	 * @return array<string, mixed[]>
@@ -11208,6 +11213,7 @@ private function gatherAssertTypes(string $file): array
 	 * @dataProvider dataBug3922
 	 * @dataProvider dataNestedGenericTypesUnwrapping
 	 * @dataProvider dataNestedGenericIncompleteConstructor
+	 * @dataProvider dataIteratorIterator
 	 * @param string $assertType
 	 * @param string $file
 	 * @param mixed ...$args

tests/PHPStan/Analyser/data/iterator-iterator.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace IteratorIteratorTest;
+
+use function PHPStan\Analyser\assertType;
+
+class Foo
+{
+
+	/**
+	 * @param \ArrayIterator<int, string> $it
+	 */
+	public function doFoo(\ArrayIterator $it): void
+	{
+		$iteratorIterator = new \IteratorIterator($it);
+		assertType('Iterator<int, string>', $iteratorIterator->getInnerIterator());
+		assertType('array<int, string>', $iteratorIterator->getArrayCopy());
+	}
+
+}