Fix #2235 - improve behaviour of array_merge on lists

vimeo · Oct 20, 2019 · b476761 · b476761
1 parent 1d6ca9b
commit b476761
Show file tree

Hide file tree

Showing 2 changed files with 23 additions and 3 deletions.
diff --git a/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php b/src/Psalm/Internal/Provider/ReturnTypeProvider/ArrayMergeReturnTypeProvider.php
@@ -33,7 +33,7 @@ public static function getFunctionReturnType(
         $codebase = $statements_source->getCodebase();
 
         $generic_properties = [];
-        $all_lists = true;
+        $all_int_offsets = true;
         $all_nonempty_lists = true;
 
         foreach ($call_args as $call_arg) {
@@ -102,7 +102,9 @@ public static function getFunctionReturnType(
                             continue;
                         }
 
-                        $all_lists = false;
+                        if (!$unpacked_type_part->type_params[0]->isInt()) {
+                            $all_int_offsets = false;
+                        }
                     }
 
                     $inner_key_types = array_merge(
@@ -130,7 +132,7 @@ public static function getFunctionReturnType(
         if ($inner_value_types) {
             $inner_value_type = TypeCombination::combineTypes($inner_value_types, $codebase, true);
 
-            if ($all_lists) {
+            if ($all_int_offsets) {
                 if ($all_nonempty_lists) {
                     return new Type\Union([
                         new Type\Atomic\TNonEmptyList($inner_value_type),

diff --git a/tests/FunctionCallTest.php b/tests/FunctionCallTest.php
@@ -240,6 +240,24 @@ function foo() { }
                     '$d' => 'array{0: string, 1: string, 2: string, 3: int, 4: int, 5: int}',
                 ],
             ],
+            'arrayMergeListResult' => [
+                '<?php
+                    /**
+                     * @param list<string> $list
+                     * @return list<string>
+                     */
+                    function foo(array $list) : array {
+                        return array_merge($list, ["test"]);
+                    }
+
+                    /**
+                     * @param array<int, string> $list
+                     * @return list<string>
+                     */
+                    function bar(array $list) : array {
+                        return array_merge($list, ["test"]);
+                    }',
+            ],
             'arrayReverseDontPreserveKey' => [
                 '<?php
                     $d = array_reverse(["a", "b", 1, "d" => 4]);',