Prevent Aggregates that use the same Models from registering multiple observers

src/Searchable/AggregatorObserver.php

@@ -47,6 +47,23 @@ public function setAggregator(string $aggregator, array $models): void
         }
     }
 
+    /**
+     * Set multiple aggregators.
+     *
+     * @param string[] $aggregators
+     * @param string $model
+     *
+     * @return void
+     */
+    public function setAggregators(array $aggregators, string $model): void
+    {
+        if (! array_key_exists($model, $this->aggregators)) {
+            $this->aggregators[$model] = [];
+        }
+
+        $this->aggregators[$model] = $aggregators;
+    }
+
     /**
      * {@inheritdoc}
      */

src/Searchable/Aggregators.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of Scout Extended.
+ *
+ * (c) Algolia Team <contact@algolia.com>
+ *
+ *  For the full copyright and license information, please view the LICENSE
+ *  file that was distributed with this source code.
+ */
+
+namespace Algolia\ScoutExtended\Searchable;
+
+class Aggregators extends Aggregator
+{
+    /**
+     * Boot multiple aggregators.
+     *
+     * @return void
+     */
+    public static function bootSearchables(array $searchables): void
+    {
+        (new static)->registerSearchableMacros();
+
+        $models = [];
+
+        foreach ($searchables as $searchable) {
+            foreach ((new $searchable)->getModels() as $model) {
+                $models[$model][] = $searchable;
+            }
+        }
+
+        foreach ($models as $model => $searchables) {
+            $observer = tap(app(AggregatorObserver::class))->setAggregators($searchables, $model);
+
+            $model::observe($observer);
+        }
+    }
+}