Fix phpstan/phpstan#10345: Array inside object used in anonymous function assumed to be empty ("Empty array passed to foreach")

src/Analyser/MutatingScope.php

@@ -36,6 +36,7 @@
 use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Node\VirtualNode;
 use PHPStan\Parser\ArrayMapArgVisitor;
+use PHPStan\Parser\ImmediatelyInvokedClosureVisitor;
 use PHPStan\Parser\Parser;
 use PHPStan\Php\PhpVersion;
 use PHPStan\Php\PhpVersionFactory;
@@ -2080,6 +2081,22 @@ public function enterAnonymousFunctionWithoutReflection(
 				}
 			}
 
+			if (
+				$expr instanceof PropertyFetch
+				|| $expr instanceof MethodCall
+				|| $expr instanceof Expr\NullsafePropertyFetch
+				|| $expr instanceof Expr\NullsafeMethodCall
+				|| $expr instanceof Expr\StaticPropertyFetch
+				|| $expr instanceof Expr\StaticCall
+			) {
+				if (
+					$closure->getAttribute(ImmediatelyInvokedClosureVisitor::ATTRIBUTE_NAME) !== true
+					&& $closure->getAttribute(NodeScopeResolver::IMMEDIATELY_CALLED_CALLBACK_ATTRIBUTE_NAME) !== true
+				) {
+					continue;
+				}
+			}
+
 			$expressionTypes[$exprString] = $typeHolder;
 		}
 

src/Analyser/NodeScopeResolver.php

@@ -187,6 +187,8 @@ class NodeScopeResolver
 	private const LOOP_SCOPE_ITERATIONS = 3;
 	private const GENERALIZE_AFTER_ITERATION = 1;
 
+	public const IMMEDIATELY_CALLED_CALLBACK_ATTRIBUTE_NAME = 'isImmediatelyCalledCallback';
+
 	/** @var array<string, true> filePath(string) => bool(true) */
 	private array $analysedFiles = [];
 
@@ -3332,8 +3334,12 @@ public function processArgs(
 				}
 
 				$this->callNodeCallbackWithExpression($nodeCallback, $arg->value, $scopeToPass, $storage, $context);
+				$callImmediately = $this->callCallbackImmediately($parameter, $parameterType, $calleeReflection);
+				if ($callImmediately) {
+					$arg->value->setAttribute(self::IMMEDIATELY_CALLED_CALLBACK_ATTRIBUTE_NAME, true);
+				}
 				$closureResult = $this->processClosureNode($stmt, $arg->value, $scopeToPass, $storage, $nodeCallback, $context, $parameterType ?? null);
-				if ($this->callCallbackImmediately($parameter, $parameterType, $calleeReflection)) {
+				if ($callImmediately) {
 					$throwPoints = array_merge($throwPoints, array_map(static fn (InternalThrowPoint $throwPoint) => $throwPoint->isExplicit() ? InternalThrowPoint::createExplicit($scope, $throwPoint->getType(), $arg->value, $throwPoint->canContainAnyThrowable()) : InternalThrowPoint::createImplicit($scope, $arg->value), $closureResult->getThrowPoints()));
 					$impurePoints = array_merge($impurePoints, $closureResult->getImpurePoints());
 					$isAlwaysTerminating = $isAlwaysTerminating || $closureResult->isAlwaysTerminating();

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -262,6 +262,7 @@ private static function findTestFiles(): iterable
 		yield __DIR__ . '/../Rules/Properties/data/bug-14012.php';
 		yield __DIR__ . '/../Rules/Variables/data/bug-14124.php';
 		yield __DIR__ . '/../Rules/Variables/data/bug-14124b.php';
+		yield __DIR__ . '/../Rules/Arrays/data/bug-10345.php';
 		yield __DIR__ . '/../Rules/Arrays/data/bug-14308.php';
 	}
 

tests/PHPStan/Analyser/nsrt/specified-types-closure-use.php

@@ -13,7 +13,7 @@ public function doFoo(MethodCall $call, MethodCall $bar): void
 	{
 		if ($call->name instanceof Identifier && $bar->name instanceof Identifier) {
 			function () use ($call): void {
-				assertType('PhpParser\Node\Identifier', $call->name);
+				assertType('PhpParser\Node\Expr|PhpParser\Node\Identifier', $call->name);
 				assertType('mixed', $bar->name);
 			};
 
@@ -26,14 +26,32 @@ public function doBar(MethodCall $call, MethodCall $bar): void
 		if ($call->name instanceof Identifier && $bar->name instanceof Identifier) {
 			$a = 1;
 			function () use ($call, &$a): void {
-				assertType('PhpParser\Node\Identifier', $call->name);
+				assertType('PhpParser\Node\Expr|PhpParser\Node\Identifier', $call->name);
 				assertType('mixed', $bar->name);
 			};
 
 			assertType('PhpParser\Node\Identifier', $call->name);
 		}
 	}
 
+	public function doImmediatelyInvoked(MethodCall $call): void
+	{
+		if ($call->name instanceof Identifier) {
+			array_map(function () use ($call): void {
+				assertType('PhpParser\Node\Identifier', $call->name);
+			}, [1]);
+		}
+	}
+
+	public function doIife(MethodCall $call): void
+	{
+		if ($call->name instanceof Identifier) {
+			(function () use ($call): void {
+				assertType('PhpParser\Node\Identifier', $call->name);
+			})();
+		}
+	}
+
 	public function doBaz(array $arr, string $key): void
 	{
 		$arr[$key] = 'test';

tests/PHPStan/Rules/Arrays/DeadForeachRuleTest.php

@@ -60,4 +60,22 @@ public function testBug8056(): void
 		$this->analyse([__DIR__ . '/data/bug-8056.php'], []);
 	}
 
+	public function testBug10345(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-10345.php'], [
+			[
+				'Empty array passed to foreach.',
+				153,
+			],
+			[
+				'Empty array passed to foreach.',
+				170,
+			],
+			[
+				'Empty array passed to foreach.',
+				185,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-10345.php

@@ -0,0 +1,188 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug10345;
+
+use function PHPStan\Testing\assertType;
+
+$container = new \stdClass();
+$container->items = [];
+
+assertType('stdClass', $container);
+assertType('array{}', $container->items);
+$func = function() use ($container): int {
+	assertType('stdClass', $container);
+	assertType('mixed', $container->items);
+	foreach ($container->items as $item) {
+	}
+	return 1;
+};
+
+$container->items[] = '1';
+
+$a = $func();
+
+class Foo {
+	/** @var list<string> */
+	public array $items = [];
+}
+
+$container2 = new Foo();
+$container2->items = [];
+
+assertType('Bug10345\Foo', $container2);
+assertType('array{}', $container2->items);
+$func2 = function() use ($container2): int {
+	assertType('Bug10345\Foo', $container2);
+	assertType('list<string>', $container2->items);
+	foreach ($container2->items as $item) {}
+	return 1;
+};
+
+$container2->items[] = '1';
+
+$a2 = $func2();
+
+class Bar {
+	/** @var list<string> */
+	private array $items = [];
+
+	/** @return list<string> */
+	public function getItems(): array
+	{
+		return $this->items;
+	}
+
+	/** @param list<string> $items */
+	public function setItems(array $items): void
+	{
+		$this->items = $items;
+	}
+}
+
+$container3 = new Bar();
+if ($container3->getItems() === []) {
+	assertType('Bug10345\Bar', $container3);
+	assertType('array{}', $container3->getItems());
+	$func3 = function() use ($container3): int {
+		assertType('Bug10345\Bar', $container3);
+		assertType('list<string>', $container3->getItems());
+		foreach ($container3->getItems() as $item) {}
+		return 1;
+	};
+
+	$container3->setItems(['foo']);
+
+	$a3 = $func3();
+}
+
+// Nullsafe property fetch
+$container4 = new Foo();
+$container4->items = [];
+
+assertType('Bug10345\Foo', $container4);
+assertType('array{}', $container4->items);
+$func4 = function() use ($container4): int {
+	assertType('Bug10345\Foo', $container4);
+	assertType('list<string>', $container4->items);
+	foreach ($container4?->items as $item) {}
+	return 1;
+};
+
+$container4->items[] = '1';
+
+$a4 = $func4();
+
+// Static property access
+class Baz {
+	/** @var list<string> */
+	public static array $items = [];
+
+	/** @return list<string> */
+	public static function getItems(): array
+	{
+		return self::$items;
+	}
+
+	/** @param list<string> $items */
+	public static function setItems(array $items): void
+	{
+		self::$items = $items;
+	}
+}
+
+Baz::$items = [];
+
+assertType('array{}', Baz::$items);
+$func5 = function(): int {
+	assertType('list<string>', Baz::$items);
+	foreach (Baz::$items as $item) {}
+	return 1;
+};
+
+Baz::$items[] = '1';
+
+$a5 = $func5();
+
+// Static method call
+Baz::setItems([]);
+if (Baz::getItems() === []) {
+	assertType('array{}', Baz::getItems());
+	$func6 = function(): int {
+		assertType('list<string>', Baz::getItems());
+		foreach (Baz::getItems() as $item) {}
+		return 1;
+	};
+
+	Baz::setItems(['foo']);
+
+	$a6 = $func6();
+}
+
+// Immediately invoked closure should keep the type
+$container7 = new \stdClass();
+$container7->items = [];
+
+assertType('stdClass', $container7);
+assertType('array{}', $container7->items);
+$result7 = array_map(
+	function() use ($container7): int {
+		assertType('stdClass', $container7);
+		assertType('array{}', $container7->items);
+		foreach ($container7->items as $item) {
+		}
+		return 1;
+	},
+	[1, 2, 3],
+);
+
+// Immediately invoked closure with declared property should also keep the type
+$container8 = new Foo();
+$container8->items = [];
+
+assertType('Bug10345\Foo', $container8);
+assertType('array{}', $container8->items);
+$result8 = array_map(
+	function() use ($container8): int {
+		assertType('Bug10345\Foo', $container8);
+		assertType('array{}', $container8->items);
+		foreach ($container8->items as $item) {}
+		return 1;
+	},
+	[1, 2, 3],
+);
+
+// IIFE should keep the type
+$container9 = new \stdClass();
+$container9->items = [];
+
+assertType('stdClass', $container9);
+assertType('array{}', $container9->items);
+$result9 = (function() use ($container9): int {
+	assertType('stdClass', $container9);
+	assertType('array{}', $container9->items);
+	foreach ($container9->items as $item) {
+	}
+	return 1;
+})();