diff --git a/README.md b/README.md
index 6b1035a..3ec1f9f 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,10 @@ File validation checks:
 2. Enable diagnostic tests in [your application configuration](https://github.com/liip/LiipMonitorBundle/blob/master/README.md).
 3. In your console type `./app/console monitor:health` to run diagnostics.
 
+## Using diagnostics with PSR-7 middleware
+
+Install the [rstgroup/diagnostics-middleware](https://github.com/rstgroup/diagnostics-middleware).
+
 ## Using diagnostics in plain PHP
 
 1. Add ZendDiagnostics component to your application
@@ -547,7 +551,7 @@ Validate that a Redis service is running.
 <?php
 use ZendDiagnostics\Check\Redis;
 
-$redisCheck = new Redis('localhost', 6379);
+$redisCheck = new Redis('localhost', 6379, 'secret');
 ```
 
 ### SecurityAdvisory
@@ -593,7 +597,7 @@ use Doctrine\DBAL\Migrations\Configuration\Configuration;
 use Doctrine\ORM\EntityManager;
 use ZendDiagnostics\Check\DoctrineMigration;
 
-$em = EntityManager::create(/** config */); 
+$em = EntityManager::create(/** config */);
 $migrationConfig = new Configuration($em);
 $check = new DoctrineMigration($migrationConfig);
 ````
diff --git a/composer.json b/composer.json
index 61a0776..64d3d2d 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,8 @@
         "videlalvaro/php-amqplib"    : "2.*",
         "predis/predis"              : "0.8.*",
         "phpunit/phpunit"            : "4.7.*",
-        "doctrine/migrations"        : "~1.0@dev"
+        "doctrine/migrations"        : "~1.0@dev",
+        "mikey179/vfsStream"         : "1.6.*"
     },
     "suggest" : {
         "ext-bcmath" : "Required by Check\\CpuPerformance",
diff --git a/src/ZendDiagnostics/Check/DirWritable.php b/src/ZendDiagnostics/Check/DirWritable.php
index e3b72a0..74e5222 100644
--- a/src/ZendDiagnostics/Check/DirWritable.php
+++ b/src/ZendDiagnostics/Check/DirWritable.php
@@ -28,7 +28,7 @@ public function __construct($path)
     {
         if (is_object($path) && !$path instanceof Traversable) {
             throw new InvalidArgumentException(
-                'Expected a dir name (string) , an array or Traversable of strings, got ' . get_class($path)
+                'Expected a dir name (string), an array or Traversable of strings, got ' . get_class($path)
             );
         }
 
@@ -67,15 +67,15 @@ public function check()
         // Construct failure message
         $failureString = '';
         if (count($nonDirs) > 1) {
-            $failureString .= 'The following paths are not valid directories: ' . join(', ', $nonDirs).' ';
+            $failureString .= sprintf('The following paths are not valid directories: %s. ', join(', ', $nonDirs));
         } elseif (count($nonDirs) == 1) {
-            $failureString .= current($nonDirs) . ' is not a valid directory. ';
+            $failureString .= sprintf('%s is not a valid directory. ', current($nonDirs));
         }
 
         if (count($unwritable) > 1) {
-            $failureString .= 'The following directories are not writable: ' . join(', ', $unwritable);
+            $failureString .= sprintf('The following directories are not writable: %s. ', join(', ', $unwritable));
         } elseif (count($unwritable) == 1) {
-            $failureString .= current($unwritable) . ' directory is not writable.';
+            $failureString .= sprintf('%s directory is not writable. ', current($unwritable));
         }
 
         // Return success or failure
@@ -83,7 +83,7 @@ public function check()
             return new Failure(trim($failureString), array('nonDirs' => $nonDirs, 'unwritable' => $unwritable));
         } else {
             return new Success(
-                count($this->dir) > 1 ? 'All paths are writable directories.' : 'The path is a a writable directory.',
+                count($this->dir) > 1 ? 'All paths are writable directories.' : 'The path is a writable directory.',
                 $this->dir
             );
         }
diff --git a/src/ZendDiagnostics/Check/HttpService.php b/src/ZendDiagnostics/Check/HttpService.php
index 617cff5..c55424c 100644
--- a/src/ZendDiagnostics/Check/HttpService.php
+++ b/src/ZendDiagnostics/Check/HttpService.php
@@ -43,7 +43,7 @@ class HttpService extends AbstractCheck
      * @param int    $port       Port to connect to (defaults to 80)
      * @param string $path       The path to retrieve (defaults to /)
      * @param int    $statusCode (optional) Expected status code
-     * @param null   $content    (optional) Expected substring to match agains the page content.
+     * @param null   $content    (optional) Expected substring to match against the page content.
      */
     public function __construct($host, $port = 80, $path = '/', $statusCode = null, $content = null)
     {
diff --git a/src/ZendDiagnostics/Check/Redis.php b/src/ZendDiagnostics/Check/Redis.php
index 4d51d6f..9c7c6f5 100644
--- a/src/ZendDiagnostics/Check/Redis.php
+++ b/src/ZendDiagnostics/Check/Redis.php
@@ -14,6 +14,11 @@
  */
 class Redis extends AbstractCheck
 {
+    /**
+     * @var string|null
+     */
+    protected $auth;
+
     /**
      * @var string
      */
@@ -25,13 +30,15 @@ class Redis extends AbstractCheck
     protected $port;
 
     /**
-     * @param string  $host
+     * @param string $host
      * @param int $port
+     * @param string|null $auth
      */
-    public function __construct($host = 'localhost', $port = 6379)
+    public function __construct($host = 'localhost', $port = 6379, $auth = null)
     {
         $this->host = $host;
         $this->port = $port;
+        $this->auth = $auth;
     }
 
     /**
@@ -49,22 +56,33 @@ public function check()
     /**
      * @return PredisClient|RedisExtensionClient
      *
+     * @throws \RedisException
      * @throws \RuntimeException
      */
     private function createClient()
     {
         if (class_exists('\Redis')) {
             $client = new RedisExtensionClient();
-            $client->connect($this->host);
+            $client->connect($this->host, $this->port);
+
+            if ($this->auth && false === $client->auth($this->auth)) {
+                throw new \RedisException('Failed to AUTH connection');
+            }
 
             return $client;
         }
 
         if (class_exists('Predis\Client')) {
-            return new PredisClient(array(
+            $parameters = array(
                 'host' => $this->host,
                 'port' => $this->port,
-            ));
+            );
+
+            if ($this->auth) {
+                $parameters['password'] = $this->auth;
+            }
+
+            return new PredisClient($parameters);
         }
 
         throw new \RuntimeException('Neither the PHP Redis extension or Predis are installed');
diff --git a/tests/ZendDiagnosticsTest/BasicConsoleReporterTest.php b/tests/ZendDiagnosticsTest/BasicConsoleReporterTest.php
index 43158fe..2995739 100644
--- a/tests/ZendDiagnosticsTest/BasicConsoleReporterTest.php
+++ b/tests/ZendDiagnosticsTest/BasicConsoleReporterTest.php
@@ -86,7 +86,6 @@ public function testUnknownSymbols()
         $this->reporter->onStart($checks, array());
         ob_clean();
 
-        ob_start();
         foreach ($checks as $alias => $check) {
             $result = new Unknown();
             $this->reporter->onAfterRun($check, $result, $alias);
@@ -104,7 +103,6 @@ public function testProgressDotsNoGutter()
         $this->reporter->onStart($checks, array());
         ob_clean();
 
-        ob_start();
         foreach ($checks as $alias => $check) {
             $result = new Success();
             $this->reporter->onAfterRun($check, $result, $alias);
@@ -122,7 +120,6 @@ public function testProgressOverflow()
         $this->reporter->onStart($checks, array());
         ob_clean();
 
-        ob_start();
         foreach ($checks as $alias => $check) {
             $result = new Success();
             $this->reporter->onAfterRun($check, $result, $alias);
@@ -145,7 +142,6 @@ public function testProgressOverflowMatch()
         $this->reporter->onStart($checks, array());
         ob_clean();
 
-        ob_start();
         foreach ($checks as $alias => $check) {
             $result = new Success();
             $this->reporter->onAfterRun($check, $result, $alias);
diff --git a/tests/ZendDiagnosticsTest/ChecksTest.php b/tests/ZendDiagnosticsTest/ChecksTest.php
index 528f2f8..fafda2b 100644
--- a/tests/ZendDiagnosticsTest/ChecksTest.php
+++ b/tests/ZendDiagnosticsTest/ChecksTest.php
@@ -392,7 +392,7 @@ public function testDirWritable()
         $result = $check->check();
         $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $result, 'Non-dir path');
         $this->assertStringMatchesFormat('%s' . $path1 . '%s', $result->getMessage());
-        $this->assertStringMatchesFormat('%s' . $path2, $result->getMessage());
+        $this->assertStringMatchesFormat('%s' . $path2 . '%s', $result->getMessage());
 
         // create a barrage of unwritable directories
         $tmpDir = sys_get_temp_dir();
@@ -453,7 +453,7 @@ public function testDirWritable()
         $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $result);
         $this->assertStringMatchesFormat('%s' . $dir1 . '%s', $result->getMessage());
         $this->assertStringMatchesFormat('%s' . $dir2 . '%s', $result->getMessage());
-        $this->assertStringMatchesFormat('%simprobabledir999999999999', $result->getMessage());
+        $this->assertStringMatchesFormat('%simprobabledir999999999999%s', $result->getMessage());
 
         chmod($dir1, 0777);
         chmod($dir2, 0777);
diff --git a/tests/ZendDiagnosticsTest/DirWritableTest.php b/tests/ZendDiagnosticsTest/DirWritableTest.php
new file mode 100644
index 0000000..657f718
--- /dev/null
+++ b/tests/ZendDiagnosticsTest/DirWritableTest.php
@@ -0,0 +1,95 @@
+<?php
+namespace ZendDiagnosticsTest;
+
+use org\bovigo\vfs\vfsStream;
+use ZendDiagnostics\Check\DirWritable;
+
+class DirWritableTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var string
+     */
+    private $checkClass = 'ZendDiagnostics\Check\DirWritable';
+
+    /**
+     * @test
+     */
+    public function shouldImplementCheckInterface()
+    {
+        $this->assertInstanceOf(
+            'ZendDiagnostics\Check\CheckInterface',
+            $this->prophesize($this->checkClass)->reveal()
+        );
+    }
+
+    /**
+     * @dataProvider providerValidConstructorArguments
+     */
+    public function testConstructor($arguments)
+    {
+        $object = new DirWritable($arguments);
+    }
+
+    public function providerValidConstructorArguments()
+    {
+        return array(
+            array(__DIR__),
+            array(vfsStream::setup()->url()),
+            array(array(__DIR__, vfsStream::setup()->url()))
+        );
+    }
+
+    public function testCheckSuccessSinglePath()
+    {
+        $object = new DirWritable(vfsStream::setup()->url());
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Success', $r);
+        $this->assertEquals('The path is a writable directory.', $r->getMessage());
+    }
+
+    public function testCheckSuccessMultiplePaths()
+    {
+        $object = new DirWritable(array(__DIR__, vfsStream::setup()->url()));
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Success', $r);
+        $this->assertEquals('All paths are writable directories.', $r->getMessage());
+    }
+
+    public function testCheckFailureSingleInvalidDir()
+    {
+        $object = new DirWritable('notadir');
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $r);
+        $this->assertContains('notadir is not a valid directory.', $r->getMessage());
+    }
+
+    public function testCheckFailureMultipleInvalidDirs()
+    {
+        $object = new DirWritable(array('notadir1', 'notadir2'));
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $r);
+        $this->assertContains('The following paths are not valid directories: notadir1, notadir2.', $r->getMessage());
+    }
+
+    public function testCheckFailureSingleUnwritableDir()
+    {
+        $root = vfsStream::setup();
+        $unwritableDir = vfsStream::newDirectory('unwritabledir', 000)->at($root);
+        $object = new DirWritable($unwritableDir->url());
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $r);
+        $this->assertEquals('vfs://root/unwritabledir directory is not writable.', $r->getMessage());
+    }
+
+    public function testCheckFailureMultipleUnwritableDirs()
+    {
+        $root = vfsStream::setup();
+        $unwritableDir1 = vfsStream::newDirectory('unwritabledir1', 000)->at($root);
+        $unwritableDir2 = vfsStream::newDirectory('unwritabledir2', 000)->at($root);
+
+        $object = new DirWritable(array($unwritableDir1->url(), $unwritableDir2->url()));
+        $r = $object->check();
+        $this->assertInstanceOf('ZendDiagnostics\Result\Failure', $r);
+        $this->assertEquals('The following directories are not writable: vfs://root/unwritabledir1, vfs://root/unwritabledir2.', $r->getMessage());
+    }
+}