Merge pull request #9651 from tuqqu/array-flip-non-empty-fix

Fix `array_flip` to preserve non-empty array type
vimeo · Apr 13, 2023 · 6834f5d · 6834f5d
2 parents cee88f2 + d3a21ac
commit 6834f5d
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Showing 2 changed files with 21 additions and 1 deletion.
diff --git a/stubs/CoreGenericFunctions.phpstub b/stubs/CoreGenericFunctions.phpstub
@@ -122,7 +122,7 @@ function array_diff_assoc(array $array, array ...$arrays)
  *
  * @param array<TKey, TValue> $array
  *
- * @return array<TValue, TKey>
+ * @return ($array is non-empty-array ? non-empty-array<TValue, TKey> : array<TValue, TKey>)
  * @psalm-pure
  */
 function array_flip(array $array)

diff --git a/tests/ArrayFunctionCallTest.php b/tests/ArrayFunctionCallTest.php
@@ -2574,6 +2574,17 @@ function takes_non_empty_int_array(array $input): void {}
                     takes_non_empty_int_array(array_unique([(object)[]]));
                 ',
             ],
+            'arrayFlipPreservesNonEmptyInput' => [
+                'code' => '<?php
+                    /** @param non-empty-array<string, int> $input */
+                    function takes_non_empty_array(array $input): void {}
+
+                    $array = ["hi", "there"];
+                    $flipped = array_flip($array);
+
+                    takes_non_empty_array($flipped);
+                ',
+            ],
         ];
     }
 
@@ -2865,6 +2876,15 @@ function takes_non_empty_list(array $input): void {}
                 ',
                 'error_message' => 'ArgumentTypeCoercion',
             ],
+            'arrayFlipPreservesEmptyInput' => [
+                'code' => '<?php
+                    /** @param non-empty-array<string, int> $input */
+                    function takes_non_empty_array(array $input): void {}
+
+                    takes_non_empty_array(array_flip([]));
+                ',
+                'error_message' => 'InvalidArgument',
+            ],
         ];
     }
 }