Fix checking list return type

Author: rvanvelzen

src/Rules/RuleLevelHelper.php

@@ -111,6 +111,7 @@ public function accepts(Type $acceptingType, Type $acceptedType, bool $strictTyp
 			$acceptedType->isArray()->yes()
 			&& $acceptingType->isArray()->yes()
 			&& !$acceptingType->isIterableAtLeastOnce()->yes()
+			&& !$acceptingType->isList()->yes()
 			&& $acceptedType->isConstantArray()->no()
 			&& $acceptingType->isConstantArray()->no()
 		) {

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1081,6 +1081,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/allowed-subtypes-throwable.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array_values.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array_keys.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/bug-8174.php');
 	}
 
 	/**

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -775,4 +775,15 @@ public function testBug3499(): void
 		$this->analyse([__DIR__ . '/data/bug-3499.php'], []);
 	}
 
+	public function testBug8174(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->analyse([__DIR__ . '/data/bug-8174.php'], [
+			[
+				"Method Bug8174\HelloWorld::filterList() should return list<string> but returns array<int<0, max>, '23423'>.",
+				21,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-8174.php

@@ -0,0 +1,23 @@
+<?php declare(strict_types = 1);
+
+namespace Bug8174;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+	/**
+	 * @param list<string> $list
+	 * @return list<string>
+	 */
+	public function filterList(array $list): array {
+		$filtered = array_filter($list, function ($elem) {
+			return $elem === '23423';
+		});
+		assertType("array<int<0, max>, '23423'>", $filtered); // this is not a list
+		assertType("list<'23423'>", array_values($filtered)); // this is a list
+
+		// why am I allowed to return not a list then?
+		return $filtered;
+	}
+}