Improve comment

Author: GromNaN

src/Collection.php

@@ -426,12 +426,15 @@ public function createSearchIndex($definition, array $options = []): string
      * Create one or more Atlas Search indexes for the collection.
      * Only available when used against a 7.0+ Atlas cluster.
      *
-     * Each element in the $indexes array must have a "name" and a "definition" document.
+     * Each element in the $indexes array must have "definition" document and they may have a "name" string.
+     * The name can be omitted for a single index, in which case a name will be the default.
      * For example:
      *
      *     $indexes = [
-     *         // Create a search index on all fields
-     *         [ 'name' => 'search_all', 'definition' => [ 'mappings' => [ 'dynamic' => true ] ] ],
+     *         // Create a search index with the default name, on
+     *         ['definition' => ['mappings' => ['dynamic' => false, 'fields' => ['title' => ['type' => 'string']]]]],
+     *         // Create a named search index on all fields
+     *         ['name' => 'search_all', 'definition' => ['mappings' => ['dynamic' => true]]],
      *     ];
      *
      * @see https://www.mongodb.com/docs/manual/reference/command/createSearchIndexes/

tests/UnifiedSpecTests/Operation.php

@@ -560,6 +560,7 @@ function (IndexInfo $info) {
             case 'createSearchIndex':
                 $options = [];
                 if (isset($args['name'])) {
+                    assertIsString($args['name']);
                     $options['name'] = $args['name'];
                 }