Issue #3122594 by jsacksick: Support "special" Search API sort fields

src/Resource/IndexResource.php

@@ -167,17 +167,8 @@ final class IndexResource extends EntityResourceBase implements ContainerInjecti
     $sort_params = $request->query->get('sort');
     $sort = Sort::createFromQueryParameter($sort_params);
 
-    $fields = array_keys($query->getIndex()->getFields());
-
-    foreach($sort->fields() as $field) {
-      $direction = $field[Sort::DIRECTION_KEY] ?? 'ASC';
-      $path = $field[Sort::PATH_KEY];
-
-      if (!in_array($path, $fields)) {
-        throw new CacheableBadRequestHttpException($cacheability, sprintf('The %s field is not sortable.', $path));
-      }
-
-      $query->sort($path, $direction);
+    foreach ($sort->fields() as $field) {
+      $query->sort($field['path'], $field['direction']);
     }
   }
 

tests/src/Functional/IndexResourceTest.php

@@ -341,13 +341,29 @@ final class IndexResourceTest extends BrowserTestBase {
       [5, 4, 3, 2, 1],
       [],
     ];
+    yield [
+      [
+        'sort' => 'search_api_id',
+      ],
+      5,
+      [1, 2, 3, 4, 5],
+      [],
+    ];
+    yield [
+      [
+        'sort' => '-search_api_id',
+      ],
+      5,
+      [5, 4, 3, 2, 1],
+      [],
+    ];
     yield [
       [
         'sort' => [
           'sort-id' => [
             'path' => 'id',
             'direction' => 'ASC',
-          ]
+          ],
         ],
       ],
       5,
@@ -360,7 +376,7 @@ final class IndexResourceTest extends BrowserTestBase {
           'sort-id' => [
             'path' => 'id',
             'direction' => 'DESC',
-          ]
+          ],
         ],
       ],
       5,