Version3

Here I start designing my model. The use of <a
href="http://verraes.net/2014/06/named-constructors-in-php/"
target="_blank">Named
constructors</a> really helps here. It allows me to think purely about
the domain at the interface level. This, for me, is where the true power
of Modelling by Example is. It's BDD and indeed TDD in its truest form.

The fundamental thing to look at, is the language of the model and how
it maps so directly the conversation with the client
`$this->house->enterRoom($room)` etc. It's DDD at play, and is a big
step forward to the `$this->house->setRoom($room)` I may have done in
the past.

It also helps point out gaps in the initial story, considerations that
haven't come up previously and thus making your model more resilient.

features/navigating-house.feature

@@ -9,17 +9,13 @@ Feature: Navigating the house
   Scenario: Getting room info
     Given I am in the "hallway"
     When I request room info
-    Then I should have room size and adjacent rooms
+    Then I should have dimensions and exits
 
   Scenario: Leaving the house
     Given I am in the "hallway"
     When I leave through the front door
     Then I should be in the "front garden"
 
-  Scenario: Entering a room that doesn't exist
-    Given I am in the "hallway"
-    Then I should not be able to enter the "made up" room
-
   Scenario: Enter a room that does exist
     Given there are the following locations in the house
       | name          | type   | width | height |
@@ -28,4 +24,8 @@ Feature: Navigating the house
       | living room   | room   | 300   | 300    |
       | kitchen       | room   | 300   | 300    |
     And I am in the "hallway"
-    Then I should be able to enter the "living room" room
+    Then I should be able to enter the "living room" room
+
+  Scenario: Entering a room that doesn't exist
+    Given I am in the "hallway"
+    Then I should not be able to enter the "made up" room

tests/contexts/HomeOwnerContext.php

@@ -2,8 +2,125 @@
 
 use Behat\Behat\Context\Context;
 use Behat\Behat\Context\SnippetAcceptingContext;
+use Behat\Gherkin\Node\TableNode;
 
 class HomeOwnerContext implements Context, SnippetAcceptingContext
 {
+    private $house;
 
-}
+    public function __construct()
+    {
+        $frontGarden = Garden::named('front garden');
+        $hallway = Room::named('hallway');
+        $livingRoom = Room::named('living room');
+        $kitchen = Room::named('kitchen');
+
+        $locations = [$frontGarden, $hallway, $livingRoom, $kitchen];
+        $this->house = House::build($locations);
+    }
+
+    /**
+     * @Given I am in the :location
+     */
+    public function iAmInThe($location)
+    {
+        $this->house->setLocation($location);
+    }
+
+    /**
+     * @When I enter through the front door
+     */
+    public function iEnterThroughTheFrontDoor()
+    {
+        $this->iEnterTheRoom('hallway');
+    }
+
+    /**
+     * @Then I should be in the :location
+     */
+    public function iShouldBeInThe($location)
+    {
+        $whereAmI = $this->house->whereAmI();
+        PHPUnit_Framework_Assert::assertEquals(Room::named($location), $whereAmI);
+    }
+
+    /**
+     * @When I request room info
+     */
+    public function iRequestRoomInfo()
+    {
+        $this->house->whereAmI()->getInformation();
+    }
+
+    /**
+     * @Then I should have dimensions and exits
+     */
+    public function iShouldHaveDimensionsAndExits()
+    {
+        $information = $this->house->whereAmI()->getInformation();
+        PHPUnit_Framework_Assert::assertArrayHasKey('dimensions', $information);
+        PHPUnit_Framework_Assert::assertArrayHasKey('exits', $information);
+    }
+
+    /**
+     * @When I leave through the front door
+     */
+    public function iLeaveThroughTheFrontDoor()
+    {
+        $frontGarden = Garden::named('front garden');
+        $this->house->exitRoom($frontGarden);
+    }
+
+    /**
+     * @Given there are the following locations in the house
+     */
+    public function thereAreTheFollowingLocationsInTheHouse(TableNode $table)
+    {
+        $locations = [];
+
+        foreach ($table->getHash() as $data) {
+            $dimensions = Dimensions::fromWidthAndHeight($data['width'], $data['height']);
+
+            if ('garden' === $data['type']) {
+                $location = Garden::named($data['name']);
+                $location->setDimensions($dimensions);
+            } else {
+                $location = Room::named($data['name']);
+                $location->setDimensions($dimensions);
+            }
+
+            $locations[] = $location;
+        }
+
+        $this->house = House::buildHouse($locations);
+    }
+
+    /**
+     * @Then I should be able to enter the :roomName room
+     */
+    public function iShouldBeAbleToEnterTheRoom($roomName)
+    {
+        $this->iEnterTheRoom($roomName);
+    }
+
+    /**
+     * @When I enter the :roomName room
+     */
+    public function iEnterTheRoom($roomName)
+    {
+        $room = Room::named($roomName);
+        $this->house->enterRoom($room);
+    }
+
+    /**
+     * @Then I should not be able to enter the :roomName room
+     */
+    public function iShouldNotBeAbleToEnterTheRoom($roomName)
+    {
+        try {
+            $this->iEnterTheRoom($roomName);
+        } catch (RoomDoesNotExistException $e) {
+            return true;
+        }
+    }
+}