diff --git a/.php_cs b/.php_cs
index 36cc3fe3a..6f85c6a7b 100644
--- a/.php_cs
+++ b/.php_cs
@@ -9,7 +9,7 @@ For the full copyright and license information, please view
 the LICENSE file that was distributed with this source code.
 EOF;
 
-$finder = Symfony\CS\Finder\DefaultFinder::create()
+$finder = PhpCsFixer\Finder::create()
     ->files()
     ->name('*.php')
     ->in(__DIR__.'/src')
@@ -17,21 +17,13 @@ $finder = Symfony\CS\Finder\DefaultFinder::create()
 ;
 
 /* fabpot/php-cs-fixer:^2.0-dev */
-return Symfony\CS\Config\Config::create()
+return  PhpCsFixer\Config::create()
     ->setRules(array(
         '@PSR2' => true,
-        'duplicate_semicolon' => true,
-        'extra_empty_lines' => true,
         'header_comment' => array('header' => $header),
         'include' => true,
-        'long_array_syntax' => true,
         'method_separation' => true,
-        'multiline_array_trailing_comma' => true,
-        'namespace_no_leading_whitespace' => true,
         'no_blank_lines_after_class_opening' => true,
-        'no_empty_lines_after_phpdocs' => true,
-        'object_operator' => true,
-        'operators_spaces' => true,
         'phpdoc_indent' => true,
         'phpdoc_no_access' => true,
         'phpdoc_no_package' => true,
@@ -39,17 +31,7 @@ return Symfony\CS\Config\Config::create()
         'phpdoc_scalar' => true,
         'phpdoc_separation' => true,
         'phpdoc_trim' => true,
-        'phpdoc_type_to_var' => true,
-        'return' => true,
-        'remove_leading_slash_use' => true,
-        'remove_lines_between_uses' => true,
-        'single_array_no_trailing_comma' => true,
         'single_blank_line_before_namespace' => true,
-        'spaces_cast' => true,
-        'standardize_not_equal' => true,
-        'ternary_spaces' => true,
-        'unused_use' => true,
-        'whitespacy_lines' => true,
     ))
-    ->finder($finder)
+    ->setFinder($finder)
 ;
diff --git a/.travis.yml b/.travis.yml
index 12bec6789..85521a446 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,5 @@
 language: php
 
-sudo: false
-
 cache:
   directories:
     - $HOME/.composer/cache
@@ -22,8 +20,7 @@ matrix:
   fast_finish: true
 
 before_script:
-  - rm -f ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/xdebug.ini
   - composer install --no-interaction --no-progress --prefer-dist
 
 script:
-  - vendor/bin/phpunit
+  - vendor/bin/phpunit -d error_reporting=16384
diff --git a/tests/Constraint/AbstractConstraintInstance.php b/tests/Constraint/AbstractConstraintInstance.php
new file mode 100644
index 000000000..90779bd18
--- /dev/null
+++ b/tests/Constraint/AbstractConstraintInstance.php
@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * This file is part of composer/semver.
+ *
+ * (c) Composer <https://github.com/composer>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Composer\Semver\Constraint;
+
+class AbstractConstraintInstance extends AbstractConstraint
+{
+    public function __toString()
+    {
+        return $this->prettyString;
+    }
+}
diff --git a/tests/Constraint/AbstractConstraintTest.php b/tests/Constraint/AbstractConstraintTest.php
new file mode 100644
index 000000000..d22ce8746
--- /dev/null
+++ b/tests/Constraint/AbstractConstraintTest.php
@@ -0,0 +1,24 @@
+<?php
+
+/*
+ * This file is part of composer/semver.
+ *
+ * (c) Composer <https://github.com/composer>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Composer\Semver\Constraint;
+
+class AbstractConstraintTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @expectedException PHPUnit_Framework_Error_Deprecated
+     */
+    public function testAbstractConstraintWithDeprecated()
+    {
+        $expectedString = 'pretty string';
+        $constraint = new AbstractConstraintInstance();
+    }
+}
diff --git a/tests/Constraint/ConstraintTest.php b/tests/Constraint/ConstraintTest.php
index dc812de7a..7fff599ab 100644
--- a/tests/Constraint/ConstraintTest.php
+++ b/tests/Constraint/ConstraintTest.php
@@ -13,6 +13,38 @@
 
 class ConstraintTest extends \PHPUnit_Framework_TestCase
 {
+    protected $constraint;
+    protected $versionProvide;
+
+    protected function setUp()
+    {
+        $this->constraint = new Constraint('==', '1');
+        $this->versionProvide = new Constraint('==', 'dev-foo');
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testVersionCompareInvalidArgumentException()
+    {
+        $result = $this->constraint->versionCompare('1.1', '1.2', null);
+    }
+
+    public function testGetPrettyString()
+    {
+        $expectedString = 'pretty-string';
+        $this->constraint->setPrettyString($expectedString);
+        $result = $this->constraint->getPrettyString();
+        
+        $this->assertSame($expectedString, $result);
+        
+        $expectedVersion = '== 1';
+        $this->constraint->setPrettyString(null);
+        $result = $this->constraint->getPrettyString();
+        
+        $this->assertSame($expectedVersion, $result);
+    }
+
     public static function successfulVersionMatches()
     {
         return array(
@@ -119,16 +151,14 @@ public function testInverseMatchingOtherConstraints()
     public function testComparableBranches()
     {
         $versionRequire = new Constraint('>', '0.12');
-        $versionProvide = new Constraint('==', 'dev-foo');
 
-        $this->assertFalse($versionRequire->matches($versionProvide));
-        $this->assertFalse($versionRequire->matchSpecific($versionProvide, true));
+        $this->assertFalse($versionRequire->matches($this->versionProvide));
+        $this->assertFalse($versionRequire->matchSpecific($this->versionProvide, true));
 
         $versionRequire = new Constraint('<', '0.12');
-        $versionProvide = new Constraint('==', 'dev-foo');
 
-        $this->assertFalse($versionRequire->matches($versionProvide));
-        $this->assertTrue($versionRequire->matchSpecific($versionProvide, true));
+        $this->assertFalse($versionRequire->matches($this->versionProvide));
+        $this->assertTrue($versionRequire->matchSpecific($this->versionProvide, true));
     }
 
     /**
diff --git a/tests/Constraint/EmptyConstraintTest.php b/tests/Constraint/EmptyConstraintTest.php
new file mode 100644
index 000000000..6208e33ab
--- /dev/null
+++ b/tests/Constraint/EmptyConstraintTest.php
@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of composer/semver.
+ *
+ * (c) Composer <https://github.com/composer>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Composer\Semver\Constraint;
+
+class EmptyConstraintTest extends \PHPUnit_Framework_TestCase
+{
+    protected $versionProvide;
+    protected $emptyConstraint;
+
+    protected function setUp()
+    {
+        $this->versionProvide = new Constraint('==', '1.1');
+        $this->emptyConstraint = new EmptyConstraint();
+    }
+
+    public function testMatches()
+    {
+        $result = $this->emptyConstraint->matches($this->versionProvide);
+        
+        $this->assertTrue($result);
+    }
+
+    public function testGetPrettyString()
+    {
+        $expectedString = 'pretty-string';
+        $this->emptyConstraint->setPrettyString($expectedString);
+        $result = $this->emptyConstraint->getPrettyString();
+        
+        $this->assertSame($expectedString, $result);
+
+        $expectedString = '[]';
+        $this->emptyConstraint->setPrettyString(null);
+        $result = $this->emptyConstraint->getPrettyString();
+        
+        $this->assertSame($expectedString, $result);
+    }
+}
diff --git a/tests/Constraint/MultiConstraintTest.php b/tests/Constraint/MultiConstraintTest.php
index 953ee42fa..85460b888 100644
--- a/tests/Constraint/MultiConstraintTest.php
+++ b/tests/Constraint/MultiConstraintTest.php
@@ -13,38 +13,84 @@
 
 class MultiConstraintTest extends \PHPUnit_Framework_TestCase
 {
+    protected $multiConstraint;
+    protected $versionRequireStart;
+    protected $versionRequireEnd;
+
+    protected function setUp()
+    {
+        $this->multiConstraint = new MultiConstraint(array());
+        $this->versionRequireStart = new Constraint('>', '1.0');
+        $this->versionRequireEnd = new Constraint('<', '1.2');
+    }
+
+    public function testIsConjunctive()
+    {
+        $result = $this->multiConstraint->isConjunctive();
+        
+        $this->assertTrue($result);
+    }
+
+    public function testIsDisjunctive()
+    {
+        $result = $this->multiConstraint->isDisjunctive();
+        
+        $this->assertFalse($result);
+    }
+
     public function testMultiVersionMatchSucceeds()
     {
-        $versionRequireStart = new Constraint('>', '1.0');
-        $versionRequireEnd = new Constraint('<', '1.2');
         $versionProvide = new Constraint('==', '1.1');
 
-        $multiRequire = new MultiConstraint(array($versionRequireStart, $versionRequireEnd));
+        $multiRequire = new MultiConstraint(array($this->versionRequireStart, $this->versionRequireEnd));
 
         $this->assertTrue($multiRequire->matches($versionProvide));
     }
 
     public function testMultiVersionProvidedMatchSucceeds()
     {
-        $versionRequireStart = new Constraint('>', '1.0');
-        $versionRequireEnd = new Constraint('<', '1.2');
         $versionProvideStart = new Constraint('>=', '1.1');
         $versionProvideEnd = new Constraint('<', '2.0');
 
-        $multiRequire = new MultiConstraint(array($versionRequireStart, $versionRequireEnd));
+        $multiRequire = new MultiConstraint(array($this->versionRequireStart, $this->versionRequireEnd));
         $multiProvide = new MultiConstraint(array($versionProvideStart, $versionProvideEnd));
 
         $this->assertTrue($multiRequire->matches($multiProvide));
     }
 
+    public function testMultiVersionMatchSucceedsInsideForeachLoop()
+    {
+        $versionProvideStart = new Constraint('>', '1.0');
+        $versionProvideEnd = new Constraint('<', '1.2');
+
+        $multiRequire = new MultiConstraint(array($this->versionRequireStart, $this->versionRequireEnd), false);
+        $multiProvide = new MultiConstraint(array($versionProvideStart, $versionProvideEnd), false);
+
+        $this->assertTrue($multiRequire->matches($multiProvide));
+    }
+
     public function testMultiVersionMatchFails()
     {
-        $versionRequireStart = new Constraint('>', '1.0');
-        $versionRequireEnd = new Constraint('<', '1.2');
         $versionProvide = new Constraint('==', '1.2');
 
-        $multiRequire = new MultiConstraint(array($versionRequireStart, $versionRequireEnd));
+        $multiRequire = new MultiConstraint(array($this->versionRequireStart, $this->versionRequireEnd));
 
         $this->assertFalse($multiRequire->matches($versionProvide));
     }
+
+    public function testGetPrettyString()
+    {
+        $multiConstraint = new MultiConstraint(array());
+        $expectedString = 'pretty-string';
+        $multiConstraint->setPrettyString($expectedString);
+        $result = $multiConstraint->getPrettyString();
+
+        $this->assertSame($expectedString, $result);
+
+        $expectedString = '[]';
+        $multiConstraint->setPrettyString(null);
+        $result = $multiConstraint->getPrettyString();
+
+        $this->assertSame($expectedString, $result);
+    }
 }
diff --git a/tests/SemverTest.php b/tests/SemverTest.php
index 878c25214..635740dba 100644
--- a/tests/SemverTest.php
+++ b/tests/SemverTest.php
@@ -58,6 +58,22 @@ public function testSort(array $versions, array $sorted, array $rsorted)
         $this->assertEquals($rsorted, Semver::rsort($versions));
     }
 
+    public function testUsortShouldInitialVersionParserClass()
+    {
+        $versions = array('1.0', '2.0', '2.1');
+        $semver = new \ReflectionClass('\Composer\Semver\Semver');
+        $versionParserProperty = $semver->getProperty('versionParser');
+        $versionParserProperty->setAccessible(true);
+        $versionParserProperty = $versionParserProperty->setValue(null);
+        
+        $manipulateVersionStringMethod = $semver->getMethod('usort');
+        $manipulateVersionStringMethod->setAccessible(true);
+        $result = $manipulateVersionStringMethod->invoke(new Semver(), $versions, 1);
+        
+        $this->assertInternalType('array', $result);
+        $this->assertCount(3, $versions);
+    }
+
     /**
      * @return array
      */
diff --git a/tests/VersionParserTest.php b/tests/VersionParserTest.php
index 87fa0d9e2..60b772665 100644
--- a/tests/VersionParserTest.php
+++ b/tests/VersionParserTest.php
@@ -23,6 +23,7 @@ class VersionParserTest extends \PHPUnit_Framework_TestCase
     public function testParseNumericAliasPrefix($input, $expected)
     {
         $parser = new VersionParser();
+
         $this->assertSame($expected, $parser->parseNumericAliasPrefix($input));
     }
 
@@ -46,6 +47,7 @@ public function numericAliasVersions()
     public function testNormalizeSucceeds($input, $expected)
     {
         $parser = new VersionParser();
+
         $this->assertSame($expected, $parser->normalize($input));
     }
 
@@ -119,12 +121,31 @@ public function failingNormalizedVersions()
         );
     }
 
+    /**
+     * @expectedException \UnexpectedValueException
+     */
+    public function testNormalizeFailsWithExtraMessage()
+    {
+        $parser = new VersionParser();
+        $parser->normalize('', '  as ');
+    }
+    
+    /**
+     * @expectedException \UnexpectedValueException
+     */
+    public function testNormalizeFailsWithOtherExtraMessage()
+    {
+        $parser = new VersionParser();
+        $parser->normalize('', '  as  123');
+    }
+
     /**
      * @dataProvider successfulNormalizedBranches
      */
     public function testNormalizeBranch($input, $expected)
     {
         $parser = new VersionParser();
+
         $this->assertSame((string) $expected, (string) $parser->normalizeBranch($input));
     }
 
@@ -150,12 +171,14 @@ public function successfulNormalizedBranches()
     public function testParseConstraintsIgnoresStabilityFlag()
     {
         $parser = new VersionParser();
+
         $this->assertSame((string) new Constraint('=', '1.0.0.0'), (string) $parser->parseConstraints('1.0@dev'));
     }
 
     public function testParseConstraintsIgnoresReferenceOnDevVersion()
     {
         $parser = new VersionParser();
+
         $this->assertSame((string) new Constraint('=', '1.0.9999999.9999999-dev'), (string) $parser->parseConstraints('1.0.x-dev#abcd123'));
         $this->assertSame((string) new Constraint('=', '1.0.9999999.9999999-dev'), (string) $parser->parseConstraints('1.0.x-dev#trunk/@123'));
     }
@@ -166,6 +189,7 @@ public function testParseConstraintsIgnoresReferenceOnDevVersion()
     public function testParseConstraintsFailsOnBadReference()
     {
         $parser = new VersionParser();
+
         $this->assertSame((string) new Constraint('=', '1.0.0.0'), (string) $parser->parseConstraints('1.0#abcd123'));
         $this->assertSame((string) new Constraint('=', '1.0.0.0'), (string) $parser->parseConstraints('1.0#trunk/@123'));
     }
@@ -189,6 +213,7 @@ public function testParseConstraintsNudgesRubyDevsTowardsThePathOfRighteousness(
     public function testParseConstraintsSimple($input, $expected)
     {
         $parser = new VersionParser();
+
         $this->assertSame((string) $expected, (string) $parser->parseConstraints($input));
     }
 
@@ -397,6 +422,7 @@ public function testParseConstraintsMultiCollapsesContiguous()
         $first = new Constraint('>=', '2.5.0.0-dev');
         $second = new Constraint('<', '4.0.0.0-dev');
         $multi = new MultiConstraint(array($first, $second));
+
         $this->assertSame((string) $multi, (string) $parser->parseConstraints('^2.5 || ^3.0'));
     }
 
@@ -413,6 +439,7 @@ public function testParseCaretConstraintsMultiDoesNotCollapseNonContiguousRange(
         ));
         $multi = new MultiConstraint(array($first, $second), false);
         $parsed = $parser->parseConstraints('^0.2 || ^1.0');
+
         $this->assertSame((string) $multi, (string) $parsed);
     }
 
@@ -432,9 +459,11 @@ public function testDoNotCollapseContiguousRangeIfOtherConstraintsAlsoApply()
         $multi = new MultiConstraint(array($first, $second), false);
 
         $version = new Constraint('=', '1.0.1.0');
+
         $this->assertFalse($multi->matches($version), 'Generated expectation should not allow version "1.0.1.0"');
 
         $parsed = $parser->parseConstraints('~0.1 || ~1.0 !=1.0.1');
+
         $this->assertFalse($parsed->matches($version), '"~0.1 || ~1.0 !=1.0.1" should not allow version "1.0.1.0"');
 
         $this->assertSame((string) $multi, (string) $parsed);
@@ -449,6 +478,7 @@ public function testParseConstraintsMulti($constraint)
         $first = new Constraint('>', '2.0.0.0');
         $second = new Constraint('<=', '3.0.0.0');
         $multi = new MultiConstraint(array($first, $second));
+
         $this->assertSame((string) $multi, (string) $parser->parseConstraints($constraint));
     }
 
@@ -477,11 +507,13 @@ public function testParseConstraintsMultiWithStabilitySuffix()
         $first = new Constraint('>=', '1.1.0.0-alpha4');
         $second = new Constraint('<', '1.2.9999999.9999999-dev');
         $multi = new MultiConstraint(array($first, $second));
+
         $this->assertSame((string) $multi, (string) $parser->parseConstraints('>=1.1.0-alpha4,<1.2.x-dev'));
 
         $first = new Constraint('>=', '1.1.0.0-alpha4');
         $second = new Constraint('<', '1.2.0.0-beta2');
         $multi = new MultiConstraint(array($first, $second));
+
         $this->assertSame((string) $multi, (string) $parser->parseConstraints('>=1.1.0-alpha4,<1.2-beta2'));
     }
 
@@ -498,6 +530,7 @@ public function testParseConstraintsMultiDisjunctiveHasPrioOverConjuctive($const
         $third = new Constraint('>', '2.0.6.0');
         $multi1 = new MultiConstraint(array($first, $second));
         $multi2 = new MultiConstraint(array($multi1, $third), false);
+
         $this->assertSame((string) $multi2, (string) $parser->parseConstraints($constraint));
     }
 
@@ -519,6 +552,7 @@ public function testParseConstraintsMultiWithStabilities()
         $first = new Constraint('>', '2.0.0.0');
         $second = new Constraint('<=', '3.0.0.0-dev');
         $multi = new MultiConstraint(array($first, $second));
+
         $this->assertSame((string) $multi, (string) $parser->parseConstraints('>2.0@stable,<=3.0@dev'));
     }
 
@@ -586,6 +620,36 @@ public function stabilityProvider()
             array('alpha', '1.2_a1'),
             array('RC', '2.0.0rc1'),
             array('alpha', '1.0.0-alpha11+cs-1.1.0'),
+            array('dev', '1-2_dev'),
         );
     }
+
+    public function testNormalizeStability()
+    {
+        $parser = new VersionParser();
+        $stability = 'rc';
+        $expectedValue = 'RC';
+        $result = $parser->normalizeStability($stability);
+
+        $this->assertSame($expectedValue, $result);
+        
+        $stability = 'no-rc';
+        $expectedValue = $stability;
+        $result = $parser->normalizeStability($stability);
+
+        $this->assertSame($expectedValue, $result);
+    }
+
+    public function testManipulateVersionStringWithReturnNull()
+    {
+        $position = 1;
+        $increment = 2;
+        $matches = array(-1, -3, -2, -5, -9);
+        $parser = new \ReflectionClass('\Composer\Semver\VersionParser');
+        $manipulateVersionStringMethod = $parser->getMethod('manipulateVersionString');
+        $manipulateVersionStringMethod->setAccessible(true);
+        $result = $manipulateVersionStringMethod->invoke(new VersionParser(), $matches, $position, $increment);
+
+        $this->assertNull($result);
+    }
 }