From a9d4837213042d38d8ac1cad0bbedc7566a19c17 Mon Sep 17 00:00:00 2001
From: Ludovic Gonthier <gonthier.ludovic@gmail.com>
Date: Thu, 16 Mar 2017 18:29:14 +0100
Subject: [PATCH] feat(cb): add trait for ease of cb use

---
 Service/CircuitBreakerService.php             |  3 +
 Tests/Traits/CircuitBreakerAwareTraitTest.php | 79 +++++++++++++++++++
 Traits/CircuitBreakerAwareTrait.php           | 65 +++++++++++++++
 3 files changed, 147 insertions(+)
 create mode 100644 Tests/Traits/CircuitBreakerAwareTraitTest.php
 create mode 100644 Traits/CircuitBreakerAwareTrait.php

diff --git a/Service/CircuitBreakerService.php b/Service/CircuitBreakerService.php
index 1ef3fe0..ccf8b70 100644
--- a/Service/CircuitBreakerService.php
+++ b/Service/CircuitBreakerService.php
@@ -14,6 +14,9 @@ class CircuitBreakerService
     const CLOSED = 'closed';
     const HALFOPEN = 'half-open';
 
+    const STATUS_UP = true;
+    const STATUS_DOWN = false;
+
     /**
      * @var AbstractAdapter
      */
diff --git a/Tests/Traits/CircuitBreakerAwareTraitTest.php b/Tests/Traits/CircuitBreakerAwareTraitTest.php
new file mode 100644
index 0000000..72a3335
--- /dev/null
+++ b/Tests/Traits/CircuitBreakerAwareTraitTest.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace Tests\CircuitBreakerBundle\Traits;
+
+use CircuitBreakerBundle\Event\CircuitBreakerEvent;
+use CircuitBreakerBundle\Service\CircuitBreakerService;
+use CircuitBreakerBundle\Traits\CircuitBreakerAwareTrait;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+class CircuitBreakerAwareTraitTest extends \PHPUnit_Framework_TestCase
+{
+    private $eventDispatcher;
+    private $circuitBreaker;
+
+    protected function setUp()
+    {
+        $this->eventDispatcher = $this->createMock(EventDispatcherInterface::class);
+        $this->circuitBreaker = $this->createMock(CircuitBreakerService::class);
+    }
+
+
+    public function testSetCircuitBreaker()
+    {
+        $trait = $this->getMockForTrait(CircuitBreakerAwareTrait::class);
+
+        $trait->setCircuitBreaker($this->circuitBreaker);
+
+        $this->assertSame(
+            $this->circuitBreaker,
+            \PHPUnit_Framework_Assert::readAttribute($trait, 'circuitBreaker')
+        );
+    }
+
+    public function testSetEventDispatcher()
+    {
+        $trait = $this->getMockForTrait(CircuitBreakerAwareTrait::class);
+
+        $trait->setEventDispatcher($this->eventDispatcher);
+
+        $this->assertSame(
+            $this->eventDispatcher,
+            \PHPUnit_Framework_Assert::readAttribute($trait, 'eventDispatcher')
+        );
+    }
+
+    public function testNotifyServiceIsDown()
+    {
+        $trait = $this->getMockForTrait(CircuitBreakerAwareTrait::class);
+        $trait->setEventDispatcher($this->eventDispatcher);
+
+        $this->eventDispatcher
+            ->expects($this->once())
+            ->method('dispatch')
+            ->with('circuit.breaker', $this->callback(function ($event) {
+                return $event instanceof CircuitBreakerEvent
+                    && $event->getKey() === 'test_service'
+                    && $event->getStatus() === CircuitBreakerService::STATUS_DOWN;
+            }));
+
+        $trait->notifyServiceIsDown('test_service');
+    }
+
+    public function testNotifyServiceIsUp()
+    {
+        $trait = $this->getMockForTrait(CircuitBreakerAwareTrait::class);
+        $trait->setEventDispatcher($this->eventDispatcher);
+
+        $this->eventDispatcher
+            ->expects($this->once())
+            ->method('dispatch')
+            ->with('circuit.breaker', $this->callback(function ($event) {
+                return $event instanceof CircuitBreakerEvent
+                    && $event->getKey() === 'test_service'
+                    && $event->getStatus() === CircuitBreakerService::STATUS_UP;
+            }));
+
+        $trait->notifyServiceIsUp('test_service');
+    }
+}
diff --git a/Traits/CircuitBreakerAwareTrait.php b/Traits/CircuitBreakerAwareTrait.php
new file mode 100644
index 0000000..e5d43e6
--- /dev/null
+++ b/Traits/CircuitBreakerAwareTrait.php
@@ -0,0 +1,65 @@
+<?php declare(strict_types = 1);
+
+namespace CircuitBreakerBundle\Traits;
+
+use CircuitBreakerBundle\Service\CircuitBreakerService;
+use CircuitBreakerBundle\Event\CircuitBreakerEvent;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+trait CircuitBreakerAwareTrait
+{
+    /**
+     * @var CircuitBreakerService
+     */
+    private $circuitBreaker;
+
+    /**
+     * @var EventDispatcherInterface
+     */
+    private $eventDispatcher;
+
+    /**
+     * Set the circuit breaker service
+     *
+     * @param CircuitBreakerService $circuitBreaker
+     */
+    public function setCircuitBreaker(CircuitBreakerService $circuitBreaker)
+    {
+        $this->circuitBreaker = $circuitBreaker;
+    }
+
+    /**
+     * @param EventDispatcherInterface $eventDispatcher
+     */
+    public function setEventDispatcher(EventDispatcherInterface $eventDispatcher)
+    {
+        $this->eventDispatcher = $eventDispatcher;
+    }
+
+
+    /**
+     * Send an event to notify the circuit breaker that a given service is down
+     *
+     * @param string $serviceName The service which is down
+     */
+    public function notifyServiceIsDown(string $serviceName)
+    {
+        $this->eventDispatcher->dispatch(
+            'circuit.breaker',
+            new CircuitBreakerEvent($serviceName, CircuitBreakerService::STATUS_DOWN)
+        );
+    }
+
+    /**
+     * Send an event to notify the circuit breaker that a given service is up
+     *
+     * @param string $serviceName The service which is up
+     */
+    public function notifyServiceIsUp(string $serviceName)
+    {
+        $this->eventDispatcher->dispatch(
+            'circuit.breaker',
+            new CircuitBreakerEvent($serviceName, CircuitBreakerService::STATUS_UP)
+        );
+    }
+}