Version19

So as you may have noticed I've been avoiding persistence throughout
this. It's a small, simple, contrived example which I didn't want to
muddy by adding any means of persistence. I realise this perhaps removes
validity to the example, but I don't really care. This is more about how to
model a domain with a modelling by example approach, as opposed to the
intricacies of database persistence with DDD.

However, I did want a tidier way of dealing with the state of the House.
Building the house in the constructor every time wasn't ideal. So I came
up with this idea of a factory. Because we all know houses come from
factories right? In essence it's more of a singleton, which works for me
here. I'm stil building the house on every request, but at least this
does it in a clear and re-usable manner. It also doesn't get me bogged
down in persistence when it's not my primary aim here.

The final thing to note is that I added some basic handlers to handle
the commands I created earlier. These are likely to change but are fine
for the time being.

spec/Jenko/House/Factory/HomeAloneHouseFactorySpec.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace spec\Jenko\House\Factory;
+
+use PhpSpec\ObjectBehavior;
+use Prophecy\Argument;
+
+class HomeAloneHouseFactorySpec extends ObjectBehavior
+{
+    function it_is_initializable()
+    {
+        $this->shouldHaveType('Jenko\House\Factory\HomeAloneHouseFactory');
+        $this->shouldHaveType('Jenko\House\Factory\HouseFactory');
+    }
+
+    function it_should_return_a_house()
+    {
+        self::getHouse()->shouldHaveType('Jenko\House\House');
+    }
+}

src/Jenko/House/Factory/HomeAloneHouseFactory.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Jenko\House\Factory;
+
+use Jenko\House\Garden;
+use Jenko\House\House;
+use Jenko\House\Room;
+
+/**
+ * Note: Usually you would have some kind of persistence mechanism. However, in our case a static factory (essentially
+ * a singleton) is fine, as the house itself won't change.
+ */
+final class HomeAloneHouseFactory implements HouseFactory
+{
+    /**
+     * @var House $house
+     */
+    private static $house;
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getHouse($currentLocation = null)
+    {
+        if (isset(static::$house)) {
+            return static::$house;
+        }
+
+        $locations = [
+            Garden::named('front garden'),
+            Room::named('hallway'),
+            Room::named('living room'),
+            Room::named('kitchen'),
+        ];
+
+        static::$house = House::build($locations);
+
+        if (null !== $currentLocation) {
+            static::$house->enterRoom($currentLocation);
+        }
+
+        return static::$house;
+    }
+}

src/Jenko/House/Factory/HouseFactory.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Jenko\House\Factory;
+
+use Jenko\House\House;
+use Jenko\House\Location;
+
+interface HouseFactory
+{
+    /**
+     * @param Location|string|null $currentLocation
+     * @return House
+     */
+    public static function getHouse($currentLocation = null);
+}

src/Jenko/House/Handler/EnterRoomHandler.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Jenko\House\Handler;
+
+use Jenko\House\Factory\HomeAloneHouseFactory;
+
+final class EnterRoomHandler
+{
+    private $house;
+
+    public function __construct()
+    {
+        $this->house = HomeAloneHouseFactory::getHouse();
+    }
+
+    /**
+     * @param $command
+     * @return mixed|void
+     */
+    public function handle($command)
+    {
+        $this->house->enterRoom($command->room);
+    }
+}

src/Jenko/House/Handler/ExitRoomHandler.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Jenko\House\Handler;
+
+use Jenko\House\Factory\HomeAloneHouseFactory;
+
+final class ExitRoomHandler
+{
+    private $house;
+
+    public function __construct()
+    {
+        $this->house = HomeAloneHouseFactory::getHouse();
+    }
+
+    /**
+     * @param $command
+     * @return mixed|void
+     */
+    public function handle($command)
+    {
+        $this->house->exitToRoom($command->room);
+    }
+}

src/Jenko/House/House.php

@@ -39,7 +39,7 @@ public static function build(array $locations)
     }
 
     /**
-     * @return array
+     * @return Location[]|array
      */
     public function getLocations()
     {