fix AbstractCursorPaginator@through types (#56267)

Author: cosmastech

src/Illuminate/Pagination/AbstractCursorPaginator.php

@@ -403,8 +403,12 @@ public function items()
  /**
  * Transform each item in the slice of items using a callback.
  *
- * @param callable $callback
- * @return $this
+ * @template TThroughValue
+ *
+ * @param callable(TValue, TKey): TThroughValue $callback
+ * @return $this<TKey, TThroughValue>
+ *
+ * @phpstan-this-out static<TKey, TThroughValue>
  */
  public function through(callable $callback)
  {

types/Pagination/Paginator.php

@@ -49,3 +49,16 @@
 foreach ($cursorPaginator as $post) {
  assertType('Post', $post);
 }
+
+$throughPaginator = clone $cursorPaginator;
+$throughPaginator->through(function ($post, $key): array {
+ assertType('int', $key);
+ assertType('Post', $post);
+
+ return [
+ 'id' => $key,
+ 'post' => $post,
+ ];
+});
+
+assertType('Illuminate\Pagination\CursorPaginator<int, array{id: int, post: Post}>', $throughPaginator);