Return empty collection when the cart is empty

src/Cart.php

@@ -205,6 +205,10 @@ class Cart
      */
     public function content()
     {
+        if (is_null($this->session->get($this->instance))) {
+            return new Collection([]);
+        }
+
         return $this->session->get($this->instance);
     }
 

tests/CartTest.php

@@ -446,6 +446,17 @@ class CartTest extends Orchestra\Testbench\TestCase
         $this->assertCount(2, $content);
     }
 
+    /** @test */
+    public function it_will_return_an_empty_collection_if_the_cart_is_empty()
+    {
+        $cart = $this->getCart();
+
+        $content = $cart->content();
+
+        $this->assertInstanceOf(\Illuminate\Support\Collection::class, $content);
+        $this->assertCount(0, $content);
+    }
+
     /** @test */
     public function it_can_destroy_a_cart()
     {