Add tests for Widget class

Author: imanghafoori1

tests/WidgetTest.php

@@ -2,8 +2,11 @@
 
 namespace Tests;
 
+use Illuminate\Contracts\Support\Renderable;
+use Illuminate\Contracts\Support\Htmlable;
 use Illuminate\Support\Facades\Response;
 use Illuminate\Support\Facades\View;
+use Imanghafoori\Widgets\Widget;
 
 class WidgetTest extends TestCase
 {
@@ -106,6 +109,13 @@ public function test_json_widgets()
         $this->assertEquals('123', $a);
     }
 
+    public function test_widget_renderable_and_htmlable()
+    {
+        $widget = new Widget();
+        $this->assertInstanceOf(Htmlable::class, $widget);
+        $this->assertInstanceOf(Renderable::class, $widget);
+    }
+
     public function test_json_widgets_as_string()
     {
         Response::shouldReceive('json')->once()->with('222111', 200)->andReturn('123');