Implement DirectoryLoader tests

composer.json

@@ -28,7 +28,8 @@
         "symfony/expression-language": "^2.7"
     },
     "require-dev": {
-        "phpunit/phpunit": "4.8.*"
+        "phpunit/phpunit": "4.8.*",
+        "mikey179/vfsStream": "^1.0"
     },
     "bin": ["bin/deprecation-detector"],
     "autoload": {

tests/RuleSet/Loader/DirectoryLoaderTest.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace SensioLabs\DeprecationDetector\Tests\RuleSet\Loader;
+
+use Prophecy\Argument;
+use SensioLabs\DeprecationDetector\RuleSet\Loader\DirectoryLoader;
+use SensioLabs\DeprecationDetector\RuleSet\RuleSet;
+
+class DirectoryLoaderTest extends \PHPUnit_Framework_TestCase
+{
+    public function testClassIsInitializable()
+    {
+        $traverser = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Traverser');
+        $cache = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Cache');
+
+        $loader = new DirectoryLoader($traverser->reveal(), $cache->reveal());
+
+        $this->assertInstanceOf('\SensioLabs\DeprecationDetector\RuleSet\Loader\DirectoryLoader', $loader);
+    }
+
+    public function testLoadRuleSetUncached()
+    {
+        $traverser = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Traverser');
+        $traverser->traverse(Argument::any())
+            ->willReturn(new RuleSet());
+
+        $cache = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Cache');
+
+        $loader = new DirectoryLoader($traverser->reveal(), $cache->reveal());
+
+        $actualRuleSet = $loader->loadRuleSet('any');
+
+        $this->assertInstanceOf('\SensioLabs\DeprecationDetector\RuleSet\RuleSet', $actualRuleSet);
+    }
+
+    public function testLoadRuleSetCached()
+    {
+        $traverser = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Traverser');
+
+        $cache = $this->prophesize('\SensioLabs\DeprecationDetector\RuleSet\Cache');
+        $cache->has(Argument::any())
+            ->willReturn(true);
+        $cache->getCachedRuleSet(Argument::any())
+            ->willReturn(new RuleSet());
+
+        $loader = new DirectoryLoader($traverser->reveal(), $cache->reveal());
+
+        $actualRuleSet = $loader->loadRuleSet('any');
+
+        $this->assertInstanceOf('\SensioLabs\DeprecationDetector\RuleSet\RuleSet', $actualRuleSet);
+    }
+}