[Fix] embed relations serialization

src/Eloquent/DocumentModel.php

@@ -754,4 +754,20 @@ public function refresh()
 
         return $this;
     }
+
+    /** @inheritDoc */
+    public function toArray()
+    {
+        $embeds = [];
+
+        foreach (array_keys($this->getAttributes()) as $key) {
+            if ($this->isEmbedRelation($key)) {
+                $embeds[] = $key;
+            }
+        }
+
+        $this->loadMissing($embeds);
+
+        return parent::toArray();
+    }
 }

src/Eloquent/EmbedsRelations.php

@@ -7,9 +7,11 @@
 use Illuminate\Support\Str;
 use MongoDB\Laravel\Relations\EmbedsMany;
 use MongoDB\Laravel\Relations\EmbedsOne;
+use MongoDB\Laravel\Relations\EmbedsOneOrMany;
 
 use function class_basename;
 use function debug_backtrace;
+use function is_a;
 
 use const DEBUG_BACKTRACE_IGNORE_ARGS;
 
@@ -85,4 +87,17 @@ protected function embedsOne($related, $localKey = null, $foreignKey = null, $re
 
         return new EmbedsOne($query, $this, $instance, $localKey, $foreignKey, $relation);
     }
+
+    /**
+     * Determine if the given key is an embed relationship method on the model.
+     *
+     * @param string $key
+     *
+     * @return bool
+     */
+    public function isEmbedRelation($key)
+    {
+        return $this->isRelation($key)
+            && is_a($this->{$key}(), EmbedsOneOrMany::class, true);
+    }
 }

tests/EmbeddedRelationsTest.php

@@ -972,4 +972,18 @@ public function testUnsetPropertyOnEmbed()
         $this->assertNull($user->addresses->get(0)->city);
         $this->assertSame('Kyoto', $user->addresses->get(1)->city);
     }
+
+    public function testEmbedManyToArrayCast()
+    {
+        $user = User::create(['name' => 'John Doe']);
+        $user->addresses()->saveMany([new Address(['city' => 'London'])]);
+
+        //Reload document
+        $user = User::where('name', 'John Doe')->first();
+        $array = $user->toArray();
+
+        $this->assertIsString($array['addresses'][0]['id']);
+        $this->assertIsString($array['addresses'][0]['created_at']);
+        $this->assertIsString($array['addresses'][0]['updated_at']);
+    }
 }