fix newFromBuilder when model is totally guarded

src/HasChildren.php

@@ -16,6 +16,10 @@ protected function initializeHasChildren()
         if ($alias = $this->classToAlias(static::class)) {
             $this->setAttribute($this->getInheritanceColumn(), $alias);
         }
+
+        if (! empty($this->getGuarded())) {
+            $this->fillable(array_merge([$this->getInheritanceColumn()], $this->getFillable()));
+        }
     }
 
     public static function bootHasChildren()
@@ -93,7 +97,7 @@ public function newInstance($attributes = [], $exists = false)
 
     public function newFromBuilder($attributes = [], $connection = null)
     {
-        $model = $this->newInstance((array) $attributes, true);
+        $model = $this->newInstance(Arr::only((array) $attributes, $this->getInheritanceColumn()), true);
 
         $model->setRawAttributes((array) $attributes, true);
 

tests/Features/ParentsReturnChildrenTest.php

@@ -4,13 +4,23 @@
 
 use Tightenco\Parental\Tests\Models\Car;
 use Tightenco\Parental\Tests\Models\Driver;
+use Tightenco\Parental\Tests\Models\GuardedChild;
+use Tightenco\Parental\Tests\Models\GuardedParent;
 use Tightenco\Parental\Tests\Models\Passenger;
 use Tightenco\Parental\Tests\Models\Plane;
 use Tightenco\Parental\Tests\Models\Vehicle;
 use Tightenco\Parental\Tests\TestCase;
 
 class ParentsAreAwareOfChildrenTest extends TestCase
 {
+    /** @test */
+    public function something()
+    {
+        $v = new GuardedParent;
+        $this->assertInstanceOf(GuardedParent::class, $v->newFromBuilder(['id' => 123]));
+        $this->assertInstanceOf(GuardedChild::class, $v->newFromBuilder(['id' => 123, 'type' => 'child']));
+    }
+
     /** @test */
     function vehicle_all_method_returns_child_models()
     {

tests/Models/GuardedChild.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Tightenco\Parental\Tests\Models;
+
+use Tightenco\Parental\HasParent;
+
+class GuardedChild extends GuardedParent
+{
+    use HasParent;
+}

tests/Models/GuardedParent.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Tightenco\Parental\Tests\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Tightenco\Parental\HasChildren;
+
+class GuardedParent extends Model
+{
+    use HasChildren;
+
+    protected $fillable = [];
+
+    protected $childTypes = ['child' => GuardedChild::class];
+}