Fix NullCache::getFrontend() and add tests

Library/Phalcon/Cache/Backend/NullCache.php

@@ -21,7 +21,7 @@ public function stop($stopBuffer = true)
 
     public function getFrontend()
     {
-        return NoneFrontend();
+        return new NoneFrontend();
     }
 
     public function getOptions()

tests/unit/Cache/Backend/NullCacheTest.php

@@ -0,0 +1,135 @@
+<?php
+
+namespace Phalcon\Test\Cache\Backend;
+
+use Phalcon\Cache\Backend\NullCache;
+use Phalcon\Test\Codeception\UnitTestCase as Test;
+use Phalcon\Cache\Frontend\None as NoneFrontend;
+
+/**
+ * \Phalcon\Test\Cache\Backend\DatabaseTest
+ * Tests for Phalcon\Cache\Backend\Database component
+ *
+ * @copyright (c) 2011-2018 Phalcon Team
+ * @link      http://www.phalconphp.com
+ * @author    Nikita Vershinin <[email protected]>
+ * @package   Phalcon\Test\Cache\Backend
+ * @group     db
+ *
+ * The contents of this file are subject to the New BSD License that is
+ * bundled with this package in the file docs/LICENSE.txt
+ *
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world-wide-web, please send an email to [email protected]
+ * so that we can send you a copy immediately.
+ */
+class NullCacheTest extends Test
+{
+    public function testStartShouldAlwaysReturnTrue()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertTrue($nullCache->start('fooBar'));
+        $this->assertTrue($nullCache->start('fooBar'), 1000);
+    }
+
+    public function testFrontendShouldBeNone()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertInstanceOf(NoneFrontend::class, $nullCache->getFrontend());
+    }
+
+    public function testGetOptionsShouldReturnEmptyArray()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertEquals([], $nullCache->getOptions());
+    }
+
+    public function testCacheShouldAlwaysBeFresh()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertTrue($nullCache->isFresh());
+    }
+
+    public function testCacheShouldAlwaysBeStarted()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertTrue($nullCache->isStarted());
+
+        $nullCache->start('fooBar');
+        $this->assertTrue($nullCache->isStarted());
+
+        $nullCache->stop();
+        $this->assertTrue($nullCache->isStarted());
+    }
+
+    public function testLastKeyShouldBeEmpty()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertEquals('', $nullCache->getLastKey());
+    }
+
+    public function testGetSomethingFromCacheShouldAlwaysReturnNull()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertEquals(null, $nullCache->get('fooBar'));
+        $this->assertEquals(null, $nullCache->get('fooBar', 1000));
+        $this->assertEquals(null, $nullCache->get('fooBar', 0));
+
+        $nullCache->save('fooBar', 'baz', 1000);
+        $this->assertEquals(null, $nullCache->get('fooBar'));
+        $this->assertEquals(null, $nullCache->get('fooBar', 1000));
+        $this->assertEquals(null, $nullCache->get('fooBar', 0));
+    }
+
+    public function testSaveSomethingToCacheShouldAlwaysReturnTrue()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertTrue($nullCache->save('fooBar', null));
+        $this->assertTrue($nullCache->save('fooBar', 'baz'));
+        $this->assertTrue($nullCache->save('fooBar', 'baz', 1000));
+        $this->assertTrue($nullCache->save('fooBar', 'baz', 1000, true));
+        $this->assertTrue($nullCache->save('fooBar', 'baz', 1000, false));
+    }
+
+    public function testDeleteSomethingFromCacheShouldAlwaysReturnTrue()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertTrue($nullCache->delete('fooBar'));
+        $this->assertFalse($nullCache->exists('fooBar'));
+
+        $randomKey = 'randomKey' . uniqid('NullCache', true);
+        $this->assertTrue($nullCache->delete($randomKey));
+        $this->assertFalse($nullCache->exists($randomKey));
+    }
+
+    public function testQueryKeysShouldReturnEmptyArray()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertEquals([], $nullCache->queryKeys());
+        $this->assertEquals([], $nullCache->queryKeys('fooBar'));
+    }
+
+    public function testNoKeyWillEverExistsInTheCache()
+    {
+        $nullCache = new NullCache();
+
+        $this->assertFalse($nullCache->exists('fooBar'));
+
+        $this->assertTrue($nullCache->save('fooBar', 'baz'));
+        $this->assertFalse($nullCache->exists('fooBar'));
+
+        $randomKey = 'randomKey' . uniqid('NullCache', true);
+        $this->assertTrue($nullCache->save('fooBar', $randomKey));
+        $this->assertFalse($nullCache->exists($randomKey));
+    }
+}