5.4 - Extracting a Named Constructor

app/Concert.php

@@ -69,16 +69,7 @@ class Concert extends Model
 
     public function createOrder($email, $tickets)
     {
-        $order = Order::create([
-            'email' => $email,
-            'amount' => $tickets->sum('price'),
-        ]);
-
-        foreach ($tickets as $ticket) {
-            $order->tickets()->save($ticket);
-        }
-
-        return $order;
+        return Order::forTickets($tickets, $email);
     }
 
     public function addTickets($quantity)

app/Http/Controllers/ConcertOrdersController.php

@@ -2,6 +2,7 @@
 
 namespace App\Http\Controllers;
 
+use App\Order;
 use App\Concert;
 use Illuminate\Http\Request;
 use App\Billing\PaymentGateway;
@@ -36,7 +37,7 @@ class ConcertOrdersController extends Controller
             $this->paymentGateway->charge(request('ticket_quantity') * $concert->ticket_price, request('payment_token'));
 
             // Create an order for those tickets
-            $order = $concert->createOrder(request('email'), $tickets);
+            $order = Order::forTickets($tickets, request('email'));
 
             return response()->json($order, 201);
 

app/Order.php

@@ -8,6 +8,20 @@ class Order extends Model
 {
     protected $guarded = [];
 
+    public static function forTickets($tickets, $email)
+    {
+        $order = self::create([
+            'email' => $email,
+            'amount' => $tickets->sum('price'),
+        ]);
+
+        foreach ($tickets as $ticket) {
+            $order->tickets()->save($ticket);
+        }
+
+        return $order;
+    }
+
     public function concert()
     {
         return $this->belongsTo(Concert::class);

tests/unit/OrderTest.php

@@ -10,6 +10,20 @@ class OrderTest extends TestCase
 {
     use DatabaseMigrations;
 
+    /** @test */
+    function creating_an_order_from_tickets_and_email()
+    {
+        $concert = factory(Concert::class)->create(['ticket_price' => 1200])->addTickets(5);
+        $this->assertEquals(5, $concert->ticketsRemaining());
+
+        $order = Order::forTickets($concert->findTickets(3), 'john@example.com');
+
+        $this->assertEquals('john@example.com', $order->email);
+        $this->assertEquals(3, $order->ticketQuantity());
+        $this->assertEquals(3600, $order->amount);
+        $this->assertEquals(2, $concert->ticketsRemaining());
+    }
+
     /** @test */
     function converting_to_an_array()
     {