Only function now doesn't include item with key 0 in every result

CHANGELOG.md

@@ -98,3 +98,6 @@
 
 ##8.1.0
 - ReplaceByKeys function added
+
+##8.1.1
+- Fixed bug: the only function always included the item with key equal to zero in the result. Caused by comparing string == 0. Also affected extract.

src/collection_functions.php

@@ -1259,7 +1259,7 @@ function only($collection, $keys)
     return filter(
         $collection,
         function ($value, $key) use ($keys) {
-            return in_array($key, $keys);
+            return in_array($key, $keys, true);
         }
     );
 }

tests/spec/CollectionSpec.php

@@ -1079,6 +1079,9 @@ function it_can_extract_data_from_nested_collections()
                 ],
                 'c' => [
                     'b' => 5
+                ],
+                [
+                    'a'
                 ]
             ]
         ];