From c271b1245eb2fc1f231d75f8f019e7f2434f7b09 Mon Sep 17 00:00:00 2001
From: AndrolGenhald <AndrolGenhald@gmail.com>
Date: Thu, 2 Jun 2022 13:59:00 -0500
Subject: [PATCH] Fix possibly empty array shape appearing non-empty (fixes
 #8048).

---
 .../ArrayMergeReturnTypeProvider.php                  |  9 +++++++++
 src/Psalm/Type/Atomic/TKeyedArray.php                 |  6 ++++--
 tests/TypeReconciliation/TypeAlgebraTest.php          | 11 +++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php
index c4002a35f..c148fdd45 100644
--- a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php
+++ b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php
@@ -214,6 +214,15 @@ class ArrayMergeReturnTypeProvider implements FunctionReturnTypeProviderInterfac
         $inner_value_type = null;
 
         if ($inner_key_types) {
+            /**
+             * @psalm-suppress InvalidScalarArgument
+             * $inner_key_types is incorrectly inferred to be array{
+             *     0?: Psalm\Type\Atomic|Psalm\Type\Atomic\TInt,
+             *     1?: Psalm\Type\Atomic|Psalm\Type\Atomic\TInt,
+             *     ...
+             *     11?: Psalm\Type\Atomic|Psalm\Type\Atomic\TInt,
+             * }
+             */
             $inner_key_type = TypeCombiner::combine($inner_key_types, $codebase, true);
         }
 
diff --git a/src/Psalm/Type/Atomic/TKeyedArray.php b/src/Psalm/Type/Atomic/TKeyedArray.php
index 15b0de859..e3b7399e5 100644
--- a/src/Psalm/Type/Atomic/TKeyedArray.php
+++ b/src/Psalm/Type/Atomic/TKeyedArray.php
@@ -408,13 +408,15 @@ class TKeyedArray extends Atomic
         return $this->getKey();
     }
 
-    public function getList(): TNonEmptyList
+    public function getList(): TList
     {
         if (!$this->is_list) {
             throw new UnexpectedValueException('Object-like array must be a list for conversion');
         }
 
-        return new TNonEmptyList($this->getGenericValueType());
+        return $this->isNonEmpty()
+            ? new TNonEmptyList($this->getGenericValueType())
+            : new TList($this->getGenericValueType());
     }
 
     /**
diff --git a/tests/TypeReconciliation/TypeAlgebraTest.php b/tests/TypeReconciliation/TypeAlgebraTest.php
index 7ee1c97d5..428c51361 100644
--- a/tests/TypeReconciliation/TypeAlgebraTest.php
+++ b/tests/TypeReconciliation/TypeAlgebraTest.php
@@ -1420,6 +1420,17 @@ class TypeAlgebraTest extends TestCase
                 false,
                 '8.1',
             ],
+            'arrayShapeListCanBeEmpty' => [
+                '<?php
+                    /** @param non-empty-list<mixed> $_list */
+                    function foobar(array $_list): void {}
+
+                    $list = random_int(0, 1) ? [] : ["foobar"];
+
+                    foobar($list);
+                ',
+                'error_message' => 'InvalidArgument',
+            ],
         ];
     }
 }