Fix array_reverse type for list{0: int, 1?: int} etc.

vimeo · Nov 6, 2024 · c297b4c · c297b4c
1 parent 0f796f1
commit c297b4c
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Showing 2 changed files with 67 additions and 10 deletions.
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReverseReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayReverseReturnTypeProvider.php
@@ -3,6 +3,7 @@
 namespace Psalm\Internal\Provider\ReturnTypeProvider;
 
 use Psalm\Internal\Analyzer\StatementsAnalyzer;
+use Psalm\Internal\Type\TypeCombiner;
 use Psalm\Plugin\EventHandler\Event\FunctionReturnTypeProviderEvent;
 use Psalm\Plugin\EventHandler\FunctionReturnTypeProviderInterface;
 use Psalm\Type;
@@ -11,6 +12,8 @@
 use Psalm\Type\Union;
 
 use function array_reverse;
+use function array_values;
+use function count;
 
 /**
  * @internal
@@ -57,17 +60,46 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
         if ($first_arg_array->is_list) {
             $second_arg = $call_args[1]->value ?? null;
 
-            if (!$second_arg
-                || (($second_arg_type = $statements_source->node_data->getType($second_arg))
-                    && $second_arg_type->isFalse()
-                )
-            ) {
-                return $first_arg_array->fallback_params
-                    ? ($first_arg_array->isNonEmpty()
+            $preserve_keys =
+                $second_arg &&
+                !(($second_arg_type = $statements_source->node_data->getType($second_arg)) &&
+                $second_arg_type->isFalse());
+            if (!$preserve_keys) {
+                if ($first_arg_array->fallback_params) {
+                    return $first_arg_array->isNonEmpty()
                         ? Type::getNonEmptyList($first_arg_array->getGenericValueType())
-                        : Type::getList($first_arg_array->getGenericValueType())
-                    )
-                    : new Union([$first_arg_array->setProperties(array_reverse($first_arg_array->properties))]);
+                        : Type::getList($first_arg_array->getGenericValueType());
+                }
+
+                $reversed_array_items = [];
+                $num_undefined = 0;
+                $i = 0;
+                foreach (array_reverse($first_arg_array->properties) as $array_item_type) {
+                    $reversed_array_items[] = $array_item_type;
+                    /** @var int<0,max> $j */
+                    $j = $i - $num_undefined;
+                    for (; $j < $i; ++$j) {
+                        $reversed_array_items[$j] = TypeCombiner::combine([
+                            ...array_values($reversed_array_items[$j]->getAtomicTypes()),
+                            ...array_values($array_item_type->getAtomicTypes()),
+                        ]);
+                    }
+                    if ($array_item_type->possibly_undefined) {
+                        ++$num_undefined;
+                    }
+                    ++$i;
+                }
+
+                $max_len = count($reversed_array_items);
+                /** @var int<0,max> $i */
+                $i = $max_len - $num_undefined;
+                for (; $i < $max_len; ++$i) {
+                    $reversed_array_items[$i] = $reversed_array_items[$i]->setPossiblyUndefined(
+                        $i >= $max_len - $num_undefined,
+                    );
+                }
+
+                return new Union([$first_arg_array->setProperties($reversed_array_items)]);
             }
 
             return new Union([new TKeyedArray(

diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
@@ -442,6 +442,31 @@ public function replace($a, $b): array
                     '$d' => 'non-empty-array<int|string, int|string>',
                 ],
             ],
+            'arrayReverseListDontPreserveKey' => [
+                'code' => '<?php
+                    /** @return list{0: int, 1: float, 2: int, 3: false, 4?: string|true, 5?: true} */
+                    function f(): array {
+                        return [1, 1.1, 2, false, "", true];
+                    }
+                    /** @return list{0: int, 1: int, 2: int, 3?: int, 4?: int} */
+                    function g(): array { return [1,2,3]; }
+
+                    $r = array_reverse(f());
+                    $s = array_reverse(g());',
+                'assertions' => [
+                    '$r' => 'list{0: bool|string, 1: bool|int|string, 2: false|float|int, 3: float|int, 4?: float|int, 5?: int}',
+                    '$s' => 'list{0: int, 1: int, 2: int, 3?: int, 4?: int}',
+                ],
+            ],
+            'arrayReverseListInt' => [
+                'code' => '<?php
+                    /** @return list<int> */
+                    function f(): array { return []; }
+                    $a = array_reverse(f());',
+                'assertions' => [
+                    '$a' => 'list<int>',
+                ],
+            ],
             'arrayReverseDontPreserveKeyExplicitArg' => [
                 'code' => '<?php
                     $d = array_reverse(["a", "b", 1, "d" => 4], false);',