Fix possibly empty array shape appearing non-empty (fixes #8048).

src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php

@@ -214,6 +214,15 @@ public static function getFunctionReturnType(FunctionReturnTypeProviderEvent $ev
         $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);
         }
 

src/Psalm/Type/Atomic/TKeyedArray.php

@@ -408,13 +408,15 @@ public function getAssertionString(bool $exact = false): string
         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());
     }
 
     /**

tests/TypeReconciliation/TypeAlgebraTest.php

@@ -1420,6 +1420,17 @@ function foo(?X $x): void {
                 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',
+            ],
         ];
     }
 }