Don’t merge array and Traversable to iterable when there are intersec…

…tions
vimeo · Oct 12, 2020 · 3887506 · 3887506
1 parent f5ed655
commit 3887506
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diff --git a/src/Psalm/Internal/Type/TypeCombination.php b/src/Psalm/Internal/Type/TypeCombination.php
@@ -261,6 +261,7 @@ public static function combineTypes(
                 || (isset($combination->named_object_types['Traversable'])
                     && $combination->named_object_types['Traversable']->from_docblock)
             )
+            && !$combination->extra_types
         ) {
             $array_param_types = $combination->array_type_params;
             $traversable_param_types = $combination->builtin_type_params['Traversable']

diff --git a/tests/ArrayAccessTest.php b/tests/ArrayAccessTest.php
@@ -964,6 +964,18 @@ function foo(array $arr) : void {
                         }
                     }'
             ],
+            'arrayAccessOnArraylikeObjectOrArray' => [
+                '<?php
+                    /**
+                     * @param (Traversable<int, string>&ArrayAccess<int, string>)|array<int, string> $arr
+                     */
+                    function test($arr): string {
+                        return $arr[0] ?? "";
+                    }
+
+                    test(["a", "b"]);
+                    test(new ArrayObject(["a", "b"]));'
+            ],
         ];
     }