#3: RotationChooser

src/Chooser/RotationChooser.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace NBN\LoadBalancer\Chooser;
+
+use NBN\LoadBalancer\Exception\NoRegisteredHostException;
+use NBN\LoadBalancer\Host\HostInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * @author Nicolas Bastien <[email protected]>
+ */
+class RotationChooser implements ChooserInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function getAvailableHost(Request $request, array $hosts)
+    {
+        if (count($hosts) == 0) {
+            throw new NoRegisteredHostException();
+        }
+
+        //basic random
+        return $hosts[array_rand($hosts)];
+    }
+}

src/Host/HostInterface.php

@@ -10,6 +10,11 @@
  */
 interface HostInterface
 {
+    /**
+     * @return string
+     */
+    public function getId();
+
     /**
      * @return float
      */

src/LoadBalancer.php

@@ -59,8 +59,8 @@ public function handleRequest(Request $request)
             throw new HostRequestException();
         }
 
+        $response->headers->set('Handled-By', $host->getId());
 
-
-
+        return $response;
     }
 }

tests/Unit/Chooser/RotationChooserTest.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace NBN\LoadBalancer\Chooser;
+
+use NBN\LoadBalancer\Exception\NoRegisteredHostException;
+use NBN\LoadBalancer\Host\HostInterface;
+
+/**
+ * vendor/bin/phpunit tests/Unit/Chooser/RotationChooserTest.php
+ *
+ * @author Nicolas Bastien <[email protected]>
+ */
+class RotationChooserTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @test RotationChooser::getAvailableHost()
+     */
+    public function testGetAvailableHostNoRegisteredHostException()
+    {
+        $request = $this->prophesize('Symfony\Component\HttpFoundation\Request');
+        $chooser = new RotationChooser();
+
+        $this->expectException(NoRegisteredHostException::class);
+        $chooser->getAvailableHost($request->reveal(), []);
+    }
+
+    /**
+     * @test RotationChooser::getAvailableHost()
+     */
+    public function testGetAvailableHost()
+    {
+        $request = $this->prophesize('Symfony\Component\HttpFoundation\Request')->reveal();
+
+        $host1 = $this->prophesize('NBN\LoadBalancer\Host\HostInterface');
+        $host1->getId()->willReturn('host-1');
+        $host1 = $host1->reveal();
+        $host2 = $this->prophesize('NBN\LoadBalancer\Host\HostInterface');
+        $host2->getId()->willReturn('host-2');
+        $host2 = $host2->reveal();
+        $host3 = $this->prophesize('NBN\LoadBalancer\Host\HostInterface');
+        $host3->getId()->willReturn('host-3');
+        $host3 = $host3->reveal();
+
+        $chooser = new RotationChooser();
+        $results = [];
+
+        for ($i=0; $i<10; $i++) {
+            $host = $chooser->getAvailableHost($request, [$host1, $host2, $host3]);
+            $this->assertTrue($host instanceof HostInterface);
+            $results[$host->getId()] = $host;
+        }
+
+        //Verify there is more than one result
+        $this->assertTrue(count($results) > 1);
+    }
+}