diff --git a/.php_cs b/.php_cs
new file mode 100644
index 0000000..a0f519b
--- /dev/null
+++ b/.php_cs
@@ -0,0 +1,20 @@
+<?php
+return PhpCsFixer\Config::create()
+    ->setRules(
+        [
+            '@Symfony' => true,
+            'array_syntax' => ['syntax' => 'short'],
+            'ordered_imports' => [
+                'imports_order' => [
+                    'class',
+                    'function',
+                    'const',
+                ],
+                'sort_algorithm' => 'alpha',
+            ],
+            'ordered_class_elements' => true,
+            'phpdoc_order' => true,
+            'header_comment' => ['header' => "For the full copyright and license information, please view the LICENSE\nfile that was distributed with this source code."],
+        ]
+    )
+    ->setCacheFile(__DIR__.'/.php_cs.cache');
diff --git a/.travis.yml b/.travis.yml
index 57c7da6..2550719 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,16 @@
 language: php
 
 php:
-  - 5.3
-  - 5.4
+  - 7.1
+  - 7.2
+  - 7.3
 
-before_script: composer install --dev
+before_install:
+  - |
+    # php.ini configuration
+    INI=~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
+    phpenv config-rm xdebug.ini || echo "xdebug not available"
+    echo memory_limit = -1 >> $INI
 
-notifications:
-  email: joris.w.dewit@gmail.com
+install:
+  - composer install --no-interaction --prefer-dist
diff --git a/AvroCaseBundle.php b/AvroCaseBundle.php
index 55b7609..b8785e7 100644
--- a/AvroCaseBundle.php
+++ b/AvroCaseBundle.php
@@ -1,5 +1,10 @@
 <?php
 
+/*
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
 namespace Avro\CaseBundle;
 
 use Symfony\Component\HttpKernel\Bundle\Bundle;
diff --git a/DependencyInjection/AvroCaseExtension.php b/DependencyInjection/AvroCaseExtension.php
index b06caea..143b25a 100644
--- a/DependencyInjection/AvroCaseExtension.php
+++ b/DependencyInjection/AvroCaseExtension.php
@@ -1,28 +1,27 @@
 <?php
 
-/**
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
 
 namespace Avro\CaseBundle\DependencyInjection;
 
-use Symfony\Component\DependencyInjection\Alias;
-use Symfony\Component\HttpKernel\DependencyInjection\Extension;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\Config\Definition\Processor;
 use Symfony\Component\Config\FileLocator;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
+use Symfony\Component\HttpKernel\DependencyInjection\Extension;
 
 /**
- * Process bundle configuration
+ * Process bundle configuration.
  *
  * @author Joris de Wit <joris.w.dewit@gmail.com>
  */
 class AvroCaseExtension extends Extension
 {
     /**
-     * Load bundle config
+     * Load bundle config.
      *
      * @param array            $configs   Config array
      * @param ContainerBuilder $container The container builder
@@ -32,7 +31,7 @@ public function load(array $configs, ContainerBuilder $container)
         $processor = new Processor();
         $configuration = new Configuration();
 
-        $config = $processor->process($configuration->getConfigTree(), $configs);
+        $config = $processor->processConfiguration($configuration, $configs);
 
         $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
 
@@ -43,4 +42,3 @@ public function load(array $configs, ContainerBuilder $container)
         }
     }
 }
-
diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index 407bd6f..bf688b8 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -1,6 +1,6 @@
 <?php
 
-/**
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
@@ -8,27 +8,29 @@
 namespace Avro\CaseBundle\DependencyInjection;
 
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
-use Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition;
+use Symfony\Component\Config\Definition\ConfigurationInterface;
 
 /**
- * This is the class that validates and merges configuration from your app/config files
+ * This is the class that validates and merges configuration from your app/config files.
  */
-class Configuration
+class Configuration implements ConfigurationInterface
 {
     /**
-     * Generates the configuration tree.
+     * Generates the configuration tree builder.
      *
-     * @return NodeInterface
+     * @return TreeBuilder The tree builder
      */
-    public function getConfigTree()
+    public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $treeBuilder->root('avro_case', 'array')
+        $treeBuilder = new TreeBuilder('avro_case');
+        $rootNode = method_exists(TreeBuilder::class, 'getRootNode') ? $treeBuilder->getRootNode() : $treeBuilder->root('avro_case');
+
+        $rootNode
             ->children()
-                ->booleanNode('use_twig')->defaultValue(true)->cannotBeEmpty()->end()
+                ->booleanNode('use_twig')->defaultValue(true)->end()
             ->end()
         ->end();
 
-        return $treeBuilder->buildTree();
+        return $treeBuilder;
     }
 }
diff --git a/README.md b/README.md
index 4c2aaab..a259d9a 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
-AvroCaseBundle [![Build Status](https://travis-ci.org/jdewit/AvroCaseBundle.png?branch=master)](https://travis-ci.org/jdewit/AvroCaseBundle)
+AvroCaseBundle [![Build Status](https://travis-ci.org/MisatoTremor/AvroCaseBundle.png?branch=master)](https://travis-ci.org/MisatoTremor/AvroCaseBundle)
 --------------
-Convert strings or an array of strings to different case formats.
+Convert strings or strings in arrays to different case formats.
 
 Supports: camelCase, PascalCase, Title Case, and underscore_case.
 
@@ -10,39 +10,60 @@ This bundle is listed on packagist.
 
 Simply add it to your apps composer.json file
 
-``` js
-    "avro/case-bundle": "0.1.2"
+```json
+    "avro/case-bundle2": "^0.4.0"
 ```
 
-Enable the bundle in the kernel:
+Enable the bundle in config/bundles.php:
 
-``` php
-// app/AppKernel.php
-
-    new Avro\CaseBundle\AvroCaseBundle
+```php
+    Avro\CaseBundle\AvroCaseBundle::class => ['all' => true],
 ```
 
 Configuration
 -------------
-``` yaml
+
+*Optional:* Add this config
+
+```yaml
+# config/packages/avro_case.yaml
 avro_case:
     use_twig: false #disable the twig extension (true by default)
 ```
 
 Usage
 -----
-``` php
-$converter = $this->container->get('avro_case.converter');
+```php
+use Avro\CaseBundle\Util\CaseConverter;
+
+class SomeClass
+{
+    private $caseConverter;
+
+    /**
+     * @param CaseConverter $caseConverter
+     */
+    public function __construct(CaseConverter $caseConverter)
+    {
+        $this->caseConverter = $caseConverter;
+    }
 
-$camelCaseFormat = $converter->toCamelCase($str);
-$pascalCaseFormat = $converter->toPascalCase($str);
-$titleCaseFormat = $converter->toTitleCase($str);
-$underscoreCaseFormat = $converter->toUnderscoreCase($str);
+    /**
+     * @param string $str
+     */
+    public function foo(string $str)
+    {
+        $camelCaseFormat = $this->converter->toCamelCase($str);
+        $pascalCaseFormat = $this->converter->toPascalCase($str);
+        $titleCaseFormat = $this->converter->toTitleCase($str);
+        $underscoreCaseFormat = $this->converter->toUnderscoreCase($str);
+    }
+}
 ```
 
 The following filters are also available if you use Twig
 
-``` jinja
+```twig
     {{ var | camel }}
     {{ var | pascal }}
     {{ var | title }}
diff --git a/Resources/config/services.yml b/Resources/config/services.yml
index 770e4a9..46d15ff 100644
--- a/Resources/config/services.yml
+++ b/Resources/config/services.yml
@@ -1,4 +1,7 @@
 services:
-    avro_case.converter:
-        class: Avro\CaseBundle\Util\CaseConverter
+    _defaults:
+        autowire: true
+        autoconfigure: true
+        public: false
 
+    Avro\CaseBundle\Util\CaseConverter: ~
diff --git a/Resources/config/twig.yml b/Resources/config/twig.yml
index 8889af7..f709d2d 100644
--- a/Resources/config/twig.yml
+++ b/Resources/config/twig.yml
@@ -1,6 +1,9 @@
 services:
-    avro_case.twig.extension:
-        class: Avro\CaseBundle\Twig\Extension\CaseExtension
+    _defaults:
+        autowire: true
+        autoconfigure: true
+        public: false
+
+    Avro\CaseBundle\Twig\Extension\CaseExtension:
         tags:
-            -  { name: twig.extension } 
-        arguments: ["@avro_case.converter"]
+            - { name: twig.extension }
diff --git a/Tests/Twig/Extension/CaseExtensionTest.php b/Tests/Twig/Extension/CaseExtensionTest.php
index 757456c..a52f787 100644
--- a/Tests/Twig/Extension/CaseExtensionTest.php
+++ b/Tests/Twig/Extension/CaseExtensionTest.php
@@ -1,6 +1,6 @@
 <?php
 
-/**
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
@@ -10,7 +10,7 @@
 use Avro\CaseBundle\Twig\Extension\CaseExtension;
 
 /**
- * Test CaseExtension Class
+ * Test CaseExtension Class.
  *
  * @author Joris de Wit <joris.w.dewit@gmail.com>
  */
@@ -27,12 +27,12 @@ class CaseExtensionTest extends \PHPUnit_Framework_TestCase
 
     public function setup()
     {
-        $this->converter = $this->getMock('Avro\CaseBundle\Util\CaseConverter');
+        $this->converter = $this->createMock('Avro\CaseBundle\Util\CaseConverter');
         $this->extension = new CaseExtension($this->converter);
     }
 
     /**
-     * @covers Avro\CaseBundle\Twig\Extension\CaseExtension::getName
+     * @covers \Avro\CaseBundle\Twig\Extension\CaseExtension::getName
      */
     public function testGetName()
     {
@@ -40,7 +40,7 @@ public function testGetName()
     }
 
     /**
-     * @covers Avro\CaseBundle\Twig\Extension\CaseExtension::getFilters
+     * @covers \Avro\CaseBundle\Twig\Extension\CaseExtension::getFilters
      */
     public function testGetFilters()
     {
@@ -51,8 +51,8 @@ public function testGetFilters()
     public function testCamelCase()
     {
         $this->converter->expects($this->any())
-                        ->method('toCamelCase')
-                        ->will($this->returnValue('camelCase'));
+            ->method('toCamelCase')
+            ->willReturn('camelCase');
         $this->assertEquals(
             'camelCase',
             $this->extension->toCamelCase('camel case')
@@ -62,8 +62,8 @@ public function testCamelCase()
     public function testPascalCase()
     {
         $this->converter->expects($this->any())
-                        ->method('toPascalCase')
-                        ->will($this->returnValue('PascalCase'));
+            ->method('toPascalCase')
+            ->will($this->returnValue('PascalCase'));
         $this->assertEquals(
             'PascalCase',
             $this->extension->toPascalCase('pascal_case')
@@ -73,8 +73,8 @@ public function testPascalCase()
     public function testTitleCase()
     {
         $this->converter->expects($this->any())
-                        ->method('toTitleCase')
-                        ->will($this->returnValue('Title Case'));
+            ->method('toTitleCase')
+            ->will($this->returnValue('Title Case'));
         $this->assertEquals(
             'Title Case',
             $this->extension->toTitleCase('title_case')
@@ -84,12 +84,11 @@ public function testTitleCase()
     public function testUnderscoreCase()
     {
         $this->converter->expects($this->any())
-                        ->method('toUnderscoreCase')
-                        ->will($this->returnValue('underscore_case'));
+            ->method('toUnderscoreCase')
+            ->will($this->returnValue('underscore_case'));
         $this->assertEquals(
             'underscore_case',
             $this->extension->toUnderscoreCase('underscore case')
         );
     }
-
 }
diff --git a/Tests/Util/CaseConverterTest.php b/Tests/Util/CaseConverterTest.php
index 7a49300..d20eb69 100644
--- a/Tests/Util/CaseConverterTest.php
+++ b/Tests/Util/CaseConverterTest.php
@@ -1,6 +1,6 @@
 <?php
 
-/**
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
@@ -8,9 +8,13 @@
 namespace Avro\CaseBundle\Tests\Util;
 
 use Avro\CaseBundle\Util\CaseConverter;
+use PHPUnit_Framework_TestCase;
 
-class CaseConverterTest extends \PHPUnit_Framework_TestCase
+class CaseConverterTest extends PHPUnit_Framework_TestCase
 {
+    /**
+     * @var CaseConverter
+     */
     private $converter;
 
     public function setUp()
@@ -90,7 +94,6 @@ public function testwordsToCamelCase()
         );
     }
 
-
     public function testTitleToPascalCase()
     {
         $this->assertEquals(
@@ -123,8 +126,6 @@ public function testWordsToPascalCase()
         );
     }
 
-
-
     public function testTitleToUnderscoreCase()
     {
         $this->assertEquals(
@@ -169,50 +170,90 @@ public function testConvert()
         );
     }
 
-    public function testArrayArguments()
+    public function testArrayArguments(): void
     {
         $this->assertEquals(
-            array(
-                'underscore_case_format1',
-                'underscore_case_format1',
-            ),
-            $this->converter->convert(array(
-                'underscoreCaseFormat1',
-                'underscoreCaseFormat1',
-            ), 'underscore')
+            [
+                'foo' => 'Title Case Format1',
+                'bar' => [
+                    'Title Case Format2',
+                    'Title Case Format3',
+                ],
+                'baz' => 'Title Case Format4',
+            ],
+            $this->converter->convert(
+                [
+                    'foo' => 'Title Case Format1',
+                    'bar' => [
+                        'title_case_format2',
+                        'title case format3',
+                    ],
+                    'baz' => 'titleCaseFormat4',
+                ],
+                'title'
+            )
         );
         $this->assertEquals(
-            array(
-                'camelCaseFormat1',
-                'camelCaseFormat2',
-            ),
-            $this->converter->convert(array(
-                'camel Case Format1',
-                'camel Case Format2',
-            ), 'camel')
+            [
+                'foo' => 'underscore_case_format1',
+                'bar' => [
+                    'underscore_case_format2',
+                    'underscore_case_format3',
+                ],
+            ],
+            $this->converter->convert(
+                [
+                    'foo' => 'underscoreCaseFormat1',
+                    'bar' => [
+                        'underscore_case_format2',
+                        'Underscore Case Format3',
+                    ],
+                ],
+                'underscore'
+            )
         );
         $this->assertEquals(
-            array(
-                'PascalCaseFormat1',
-                'PascalCaseFormat2',
-            ),
-            $this->converter->convert(array(
-                'pascal_case_format1',
-                'pascal_case_format2',
-            ), 'pascal')
+            [
+                'foo' => 'camelCaseFormat1',
+                'bar' => [
+                    'camelCaseFormat2',
+                    'camelCaseFormat3',
+                ],
+            ],
+            $this->converter->convert(
+                [
+                    'foo' => 'camelCaseFormat1',
+                    'bar' => [
+                        'camel_case_format2',
+                        'camel Case Format3',
+                    ],
+                ],
+                'camel'
+            )
         );
-        $this->assertEquals(array(
-                'Title Case Format1',
-                'Title Case Format2',
-            ),
-            $this->converter->convert(array(
-                'title case format1',
-                'title case format2',
-            ), 'title')
+        $this->assertEquals(
+            [
+                'foo' => 'PascalCaseFormat1',
+                'bar' => [
+                    'PascalCaseFormat2',
+                    'PascalCaseFormat3',
+                ],
+                'baz' => 'PascalCaseFormat4',
+            ],
+            $this->converter->convert(
+                [
+                    'foo' => 'PascalCaseFormat1',
+                    'bar' => [
+                        'pascal_case_format2',
+                        'pascal case format3',
+                    ],
+                    'baz' => 'Pascal Case Format4',
+                ],
+                'pascal'
+            )
         );
     }
 
-
     public function testGetFormat()
     {
         $this->assertEquals(
@@ -235,7 +276,4 @@ public function testGetFormat()
             $this->converter->getFormat('Title Case Format')
         );
     }
-
-
 }
-
diff --git a/Twig/Extension/CaseExtension.php b/Twig/Extension/CaseExtension.php
index 1568e4e..9d138eb 100644
--- a/Twig/Extension/CaseExtension.php
+++ b/Twig/Extension/CaseExtension.php
@@ -1,6 +1,6 @@
 <?php
 
-/**
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
@@ -10,7 +10,7 @@
 use Avro\CaseBundle\Util\CaseConverter;
 
 /**
- * Twig extension for case conversion
+ * Twig extension for case conversion.
  *
  * @author Joris de Wit <joris.w.dewit@gmail.com>
  */
@@ -27,22 +27,22 @@ public function __construct(CaseConverter $caseConverter)
     }
 
     /**
-     * Get twig filters
+     * Get twig filters.
      *
      * @return array filters
      */
     public function getFilters()
     {
-        return array(
-            new \Twig_SimpleFilter('camel', array($this, 'toCamelCase')),
-            new \Twig_SimpleFilter('pascal', array($this, 'toPascalCase')),
-            new \Twig_SimpleFilter('underscore', array($this, 'toUnderscoreCase')),
-            new \Twig_SimpleFilter('title', array($this, 'toTitleCase'))
-        );
+        return [
+            new \Twig_SimpleFilter('camel', [$this, 'toCamelCase']),
+            new \Twig_SimpleFilter('pascal', [$this, 'toPascalCase']),
+            new \Twig_SimpleFilter('underscore', [$this, 'toUnderscoreCase']),
+            new \Twig_SimpleFilter('title', [$this, 'toTitleCase']),
+        ];
     }
 
     /**
-     * Convert string to camel case format
+     * Convert string to camel case format.
      *
      * @param string $input
      *
@@ -54,7 +54,7 @@ public function toCamelCase($input)
     }
 
     /**
-     * Convert string to pascal case format
+     * Convert string to pascal case format.
      *
      * @param string $input
      *
@@ -66,7 +66,7 @@ public function toPascalCase($input)
     }
 
     /**
-     * Convert string to underscore case format
+     * Convert string to underscore case format.
      *
      * @param string $input
      *
@@ -78,7 +78,7 @@ public function toUnderscoreCase($input)
     }
 
     /**
-     * Convert string to title case format
+     * Convert string to title case format.
      *
      * @param string $input
      *
@@ -90,7 +90,7 @@ public function toTitleCase($input)
     }
 
     /**
-     * Get twig extension name
+     * Get twig extension name.
      *
      * @return string
      */
diff --git a/UPGRADE.md b/UPGRADE.md
new file mode 100644
index 0000000..23898af
--- /dev/null
+++ b/UPGRADE.md
@@ -0,0 +1,4 @@
+Changes in version 0.4
+----------------------
+
+* ``CaseConverter::convertToTitleCase`` is now private, use ``toTitleCase`` instead
diff --git a/Util/CaseConverter.php b/Util/CaseConverter.php
index 93182ff..e0c62c6 100644
--- a/Util/CaseConverter.php
+++ b/Util/CaseConverter.php
@@ -1,6 +1,8 @@
 <?php
 
-/**
+declare(strict_types=1);
+
+/*
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
@@ -8,15 +10,14 @@
 namespace Avro\CaseBundle\Util;
 
 /**
- * Convert strings into different case formats
+ * Convert strings into different case formats.
  *
  * @author Joris.w.dewit <joris.w.dewit@gmail.com>
- *
  */
 class CaseConverter
 {
     /**
-     * Converts a string into underscore format (e.g. first_name)
+     * Converts a string into underscore format (e.g. first_name).
      *
      * @param string|array $input String
      *
@@ -25,118 +26,216 @@ class CaseConverter
     public function toUnderscoreCase($input)
     {
         if (is_array($input)) {
-            $result = array();
-            foreach ($input as $val) {
-                $result[] = $this->convertToUnderscoreCase($val);
-            }
-        } else {
-            $result = $this->convertToUnderscoreCase($input);
+            return array_map([$this, 'toUnderscoreCase'], $input);
+        }
+        if (is_string($input)) {
+            return $this->convertToUnderscoreCase($input);
         }
 
-        return $result;
+        return $input;
     }
 
     /**
-     * Converts a string into underscore format (e.g. first_name)
+     * Converts a string or array into title format (e.g. First Name).
      *
      * @param string|array $input String
      *
-     * @return string $input In underscore format
+     * @return string|array $result In title case format
      */
-    private function convertToUnderscoreCase($input)
+    public function toTitleCase($input)
     {
-        $input = trim(lcfirst($input));
+        if (is_array($input)) {
+            return array_map([$this, 'toTitleCase'], $input);
+        }
+        if (is_string($input)) {
+            return $this->convertToTitleCase($input);
+        }
 
-        // camel case
-        $input = preg_replace_callback('/([A-Z])/', create_function('$c', 'return "_" . strtolower($c[1]);'), $input);
+        return $input;
+    }
 
-        // title case
-        $input = str_replace(' ', '', $input);
+    /**
+     * Converts a string to camel case format (e.g. firstName).
+     *
+     * @param string|array $input String or array argument
+     *
+     * @return string|array $result In camel case format
+     */
+    public function toCamelCase($input)
+    {
+        if (is_array($input)) {
+            return array_map([$this, 'toCamelCase'], $input);
+        }
+        if (is_string($input)) {
+            return $this->convertToCamelCase($input);
+        }
 
         return $input;
     }
 
     /**
-     * Converts a string or array into title format (e.g. First Name)
+     * Converts a string to pascal case format (e.g. FirstName).
      *
-     * @param string|array $input String
+     * @param string|array $input String or array argument
      *
-     * @return string|array $result In title case format
+     * @return string|array $result In pascal case format
      */
-    public function toTitleCase($input)
+    public function toPascalCase($input)
     {
         if (is_array($input)) {
-            $result = array();
-            foreach ($input as $val) {
-                $result[] = $this->convertToTitleCase($val);
-            }
-        } else {
-            $result = $this->convertToTitleCase($input);
+            return array_map([$this, 'toPascalCase'], $input);
+        }
+        if (is_string($input)) {
+            return $this->convertToPascalCase($input);
         }
 
-        return $result;
+        return $input;
+    }
+
+    /**
+     * Convert string.
+     *
+     * @param string|array $input  Input argument as string or array
+     * @param string|array $format Desired Case format
+     *
+     * @return string|array
+     */
+    public function convert($input, $format = 'camel')
+    {
+        switch ($format) {
+            case 'pascal':
+                return $this->toPascalCase($input);
+                break;
+            case 'title':
+                return $this->toTitleCase($input);
+                break;
+            case 'underscore':
+                return $this->toUnderscoreCase($input);
+                break;
+            case 'camel':
+            default:
+                return $this->toCamelCase($input);
+                break;
+        }
     }
 
     /**
-     * Converts a string into title format (e.g. First Name)
+     * Get the format of a string.
+     *
+     * @param string $input The input string
+     *
+     * @return string The strings format
+     */
+    public function getFormat(string $input): string
+    {
+        if (strpos($input, ' ')) {
+            return 'title';
+        }
+        if (strpos($input, '_')) {
+            return 'underscore';
+        }
+        if ($input[0] === strtoupper($input[0])) {
+            return 'pascal';
+        }
+
+        return 'camel';
+    }
+
+    /**
+     * Converts a string into title format (e.g. First Name).
      *
      * @param string $input String
      *
      * @return string $input Translated into title format
      */
-    public function convertToTitleCase($input)
+    private function convertToTitleCase(string $input): string
     {
         $input = ucfirst($input);
 
         // camelCase
-        $input = preg_replace_callback('/([A-Z])/', create_function('$c', 'return " " . ucfirst($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/([A-Z])/',
+            static function ($c) {
+                return ' '.ucfirst($c[1]);
+            },
+            $input
+        );
 
         // lowercase title
-        $input = preg_replace_callback('/ ([a-z])/', create_function('$c', 'return " " . ucfirst($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/ ([a-z])/',
+            static function ($c) {
+                return ' '.ucfirst($c[1]);
+            },
+            $input
+        );
 
         // underscore
-        $input = preg_replace_callback('/_([a-z])/', create_function('$c', 'return " " . strtoupper($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/_([a-z])/',
+            static function ($c) {
+                return ' '.strtoupper($c[1]);
+            },
+            $input
+        );
 
         return trim(preg_replace('/\s+/', ' ', $input));
     }
 
     /**
-     * Converts a string to camel case format (e.g. firstName)
+     * Converts a string into underscore format (e.g. first_name).
      *
-     * @param string|array $input String or array argument
+     * @param string $input String
      *
-     * @return string $result or array with values translated into camel case
+     * @return string $input In underscore format
      */
-    public function toCamelCase($input)
+    private function convertToUnderscoreCase(string $input): string
     {
-        if (is_array($input)) {
-            $result = array();
-            foreach ($input as $val) {
-                $result[] = $this->convertToCamelCase($val);
-            }
-        } else {
-            $result = $this->convertToCamelCase($input);
-        }
+        $input = lcfirst(trim($input));
+
+        // camel case
+        $input = preg_replace_callback(
+            '/([A-Z])/',
+            static function ($c) {
+                return '_'.strtolower($c[1]);
+            },
+            $input
+        );
 
-        return $result;
+        // title case
+        $input = str_replace(' ', '', $input);
+
+        return $input;
     }
 
     /**
-     * Convert a string to camel case
+     * Convert a string to camel case.
      *
      * @param string $input Variable to convert
      *
      * @return string $input In Camel case format
      */
-    private function convertToCamelCase($input)
+    private function convertToCamelCase(string $input): string
     {
         $input = lcfirst($input);
 
         // underscore
-        $input = preg_replace_callback('/_([a-z])/', create_function('$c', 'return strtoupper($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/_([a-z])/',
+            static function ($c) {
+                return strtoupper($c[1]);
+            },
+            $input
+        );
 
         // title
-        $input = preg_replace_callback('/ ([a-z])/', create_function('$c', 'return strtoupper($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/ ([a-z])/',
+            static function ($c) {
+                return strtoupper($c[1]);
+            },
+            $input
+        );
 
         $input = str_replace(' ', '', $input);
 
@@ -144,92 +243,36 @@ private function convertToCamelCase($input)
     }
 
     /**
-     * Converts a string to pascal case format (e.g. FirstName)
-     *
-     * @param string|array $input String or array argument
-     *
-     * @return string|array $result translated into pascal case
-     */
-    public function toPascalCase($input)
-    {
-        if (is_array($input)) {
-            $result = array();
-            foreach ($input as $val) {
-                $result[] = $this->convertToPascalCase($val);
-            }
-        } else {
-            $result = $this->convertToPascalCase($input);
-        }
-
-        return $result;
-    }
-
-    /**
-     * Converts a string to pascal case format (e.g. FirstName)
+     * Converts a string to pascal case format (e.g. FirstName).
      *
      * @param string|array $input String
      *
      * @return string $input translated into pascal case
      */
-    private function convertToPascalCase($input)
+    private function convertToPascalCase(string $input): string
     {
         $input = ucfirst($input);
 
         // underscore
-        $input = preg_replace_callback('/_([a-z])/', create_function('$c', 'return strtoupper($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/_([a-z])/',
+            static function ($c) {
+                return strtoupper($c[1]);
+            },
+            $input
+        );
 
         // title
-        $input = preg_replace_callback('/ ([a-z])/', create_function('$c', 'return strtoupper($c[1]);'), $input);
+        $input = preg_replace_callback(
+            '/ ([a-z])/',
+            static function ($c) {
+                return strtoupper($c[1]);
+            },
+            $input
+        );
 
         $input = str_replace(' ', '', $input);
 
         return $input;
     }
-
-    /**
-     * Convert string
-     *
-     * @param string|array $input  Input argument as string or array
-     * @param string|array $format Desired Case format
-     *
-     * @return string
-     */
-    public function convert($input, $format = 'camel')
-    {
-        switch($format) {
-            case 'camel':
-                return $this->toCamelCase($input);
-                break;
-            case 'pascal':
-                return $this->toPascalCase($input);
-                break;
-            case 'title':
-                return $this->toTitleCase($input);
-                break;
-            case 'underscore':
-                return $this->toUnderscoreCase($input);
-                break;
-        }
-    }
-
-    /**
-     * Get the format of a string
-     *
-     * @param string $input The input string
-     *
-     * @return string The strings format
-     */
-    public function getFormat($input)
-    {
-        if (strpos($input, ' ')) {
-            return 'title';
-        } else if (strpos($input, '_')) {
-            return 'underscore';
-        } else if ($input{0} === strtoupper($input{0})) {
-            return 'pascal';
-        } else {
-            return 'camel';
-        }
-    }
-
 }
diff --git a/composer.json b/composer.json
index b891acc..013a697 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
-    "name": "avro/case-bundle",
+    "name": "avro/case-bundle2",
     "type": "symfony-bundle",
-    "description": "Symfony2 Case Converter Bundle",
+    "description": "Symfony Case Converter Bundle",
     "keywords": ["pascal", "title", "camel", "converter"],
     "homepage": "http://github.com/jdewit/AvroCaseBundle",
     "license": "MIT",
@@ -9,15 +9,29 @@
         {
             "name": "Joris de Wit",
             "email": "joris.w.dewit@gmail.com"
+        },
+        {
+            "name": "Steffen Roßkamp",
+            "email": "sr@blackblizzard.org"
         }
     ],
     "minimum-stability": "dev",
+    "extra": {
+        "branch-alias": {
+            "dev-master": "0.4-dev"
+        }
+    },
     "require": {
-        "php": ">=5.3.2",
-        "twig/twig": "^1.12.0"
+        "php": "^7.1.3",
+        "twig/twig": "^1.12.0 || ^2.0"
     },
-    "autoload": {
-        "psr-0": { "Avro\\CaseBundle": "" }
+    "require-dev": {
+        "phpunit/phpunit": "^5.7",
+        "symfony/config": "~4.0",
+        "symfony/dependency-injection": "~4.0",
+        "symfony/http-kernel": "~4.0"
     },
-    "target-dir": "Avro/CaseBundle"
+    "autoload": {
+        "psr-4": { "Avro\\CaseBundle\\": "" }
+    }
 }