IterableType - fix getReferencedTemplateTypes

src/Type/IterableType.php

@@ -359,8 +359,8 @@ public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 	public function getReferencedTemplateTypes(TemplateTypeVariance $positionVariance): array
 	{
 		return array_merge(
-			$this->getIterableKeyType()->getReferencedTemplateTypes(TemplateTypeVariance::createCovariant()),
-			$this->getIterableValueType()->getReferencedTemplateTypes(TemplateTypeVariance::createCovariant()),
+			$this->getIterableKeyType()->getReferencedTemplateTypes($positionVariance),
+			$this->getIterableValueType()->getReferencedTemplateTypes($positionVariance),
 		);
 	}
 

tests/PHPStan/Rules/Generics/MethodSignatureVarianceRuleTest.php

@@ -176,4 +176,14 @@ public function testRule(): void
 		]);
 	}
 
+	public function testBug8880(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-8880.php'], [
+			[
+				'Template type T is declared as covariant, but occurs in contravariant position in parameter items of method Bug8880\IProcessor::processItems().',
+				17,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Generics/data/bug-8880.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Bug8880;
+
+function putStrLn(string $s): void {
+	echo $s, PHP_EOL;
+}
+
+/**
+ * @template-covariant T
+ */
+interface IProcessor {
+	/**
+	 * @param iterable<T> $items
+	 * @return void
+	 */
+	function processItems($items);
+}
+
+/** @implements IProcessor<string> */
+final class StringPrinter implements IProcessor {
+	function processItems($items) {
+		foreach ($items as $s)
+			putStrLn($s);
+	}
+}
+
+/**
+ * @param IProcessor<string | int> $p
+ * @return void
+ */
+function callWithInt($p) {
+	$p->processItems([1]);
+}