Support generator for foreEach

Author: Meldiron

src/Database/Database.php

@@ -7863,10 +7863,10 @@ public function find(string $collection, array $queries = [], string $forPermiss
      * @param callable $callback
      * @param array<Query> $queries
      * @param string $forPermission
-     * @return void
+     * @return \Generator
      * @throws \Utopia\Database\Exception
      */
-    public function foreach(string $collection, callable $callback, array $queries = [], string $forPermission = Database::PERMISSION_READ): void
+    public function foreach(string $collection, ?callable $callback = null, array $queries = [], string $forPermission = Database::PERMISSION_READ): \Generator
     {
         $grouped = Query::groupByType($queries);
         $limitExists = $grouped['limit'] !== null;
@@ -7906,8 +7906,10 @@ public function foreach(string $collection, callable $callback, array $queries =
             $sum = count($results);
 
             foreach ($results as $document) {
-                if (is_callable($callback)) {
+                if (!is_null($callback) && is_callable($callback)) {
                     $callback($document);
+                } else {
+                    yield $document;
                 }
             }
 

tests/e2e/Adapter/Scopes/DocumentTests.php

@@ -4014,6 +4014,26 @@ public function testForeach(): void
         /** @var Database $database */
         $database = $this->getDatabase();
 
+        /**
+         * Test, foreach without callback on empty collection
+         */
+        $database->createCollection('moviesEmpty');
+        $documents = [];
+        foreach ($database->foreach('movies', queries: [Query::limit(2)], ) as $document) {
+            $documents[] = $document;
+        }
+        $this->assertEquals(0, \count($documents));
+        $this->assertTrue($database->deleteCollection('moviesEmpty'));
+
+        /**
+         * Test, foreach without callback
+         */
+        $documents = [];
+        foreach ($database->foreach('movies', queries: [Query::limit(2)], ) as $document) {
+            $documents[] = $document;
+        }
+        $this->assertEquals(6, count($documents));
+
         /**
          * Test, foreach goes through all the documents
          */