ArrayFilterFunctionReturnTypeReturnTypeExtension handle error types

Author: mglaman

src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php

@@ -23,6 +23,7 @@
 use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\ErrorType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NeverType;
 use PHPStan\Type\NullType;
@@ -54,9 +55,13 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		}
 
 		$arrayArgType = $scope->getType($arrayArg);
+		$arrayArgType->isArray();
 		$keyType = $arrayArgType->getIterableKeyType();
 		$itemType = $arrayArgType->getIterableValueType();
 
+		if ($itemType instanceof ErrorType || $keyType instanceof ErrorType) {
+			return new ConstantArrayType([], []);
+		}
 		if ($itemType instanceof NeverType || $keyType instanceof NeverType) {
 			return new ConstantArrayType([], []);
 		}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1386,6 +1386,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8366.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7291.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/conditional-vars.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-10189.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-10189.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Bug10189;
+
+use function PHPStan\Testing\assertType;
+
+interface SomeInterface {
+}
+
+/**
+ * @return array|SomeInterface|null|false
+ */
+function _file_save_upload_from_form() {
+	return [];
+}
+
+function file_managed_file_save_upload(): array {
+	if (!$files = _file_save_upload_from_form()) {
+		return [];
+	}
+	assertType('non-empty-array|Bug10189\SomeInterface', $files);
+	$files = array_filter($files);
+	assertType('array{}', $files);
+
+	return empty($files) ? [] : [1,2];
+}