refactor formatDate function and create test

.travis.yml

@@ -10,6 +10,8 @@ env:
   - DB_USER=root
 
 before_script:
+  - sudo apt-get update -qq
+  - sudo apt-get install -y language-pack-fr language-pack-fr-base
   - phpenv config-add travis.php.ini
   - composer self-update
   - composer install --prefer-dist --dev

core/lib/Thelia/Core/Template/Smarty/Plugins/Format.php

@@ -89,24 +89,31 @@ class Format extends AbstractSmartyPlugin
 
         $locale = $this->getParam($params,'locale', false);
 
-        if($locale === false) {
-            return $date->format($format);
+        if (false === $locale) {
+            $value = $date->format($format);
         } else {
-            if(function_exists('setlocale')) {
-                // Save the current locale
-                $system_locale = setlocale('LC_TIME', 0);
-                setlocale('LC_TIME', $locale);
-                $localized_date =  strftime($format, $date->getTimestamp());
-                // Restore the locale
-                setlocale('LC_TIME', $system_locale);
+            $value = $this->formatDateWithLocale($date, $locale, $format);
+        }
 
-                return $localized_date;
+        return $value;
+    }
+
+    private function formatDateWithLocale(\DateTime $date, $locale, $format)
+    {
+        if (function_exists('setlocale')) {
+            // Save the current locale
+            $systemLocale = setlocale('LC_TIME', 0);
+            setlocale('LC_TIME', $locale);
+            $localizedDate =  strftime($format, $date->getTimestamp());
+            // Restore the locale
+            setlocale('LC_TIME', $systemLocale);
+
+            return $localizedDate;
         } else {
             // setlocale() function not available => error
             throw new SmartyPluginException("The setlocale() function is not available on your system.");
         }
     }
-    }
 
     /**
      *

core/lib/Thelia/Tests/Core/Template/Smarty/Plugins/FormatTest.php

@@ -158,6 +158,23 @@ class FormatTest extends \PHPUnit_Framework_TestCase
         $this->assertEmpty($render);
     }
 
+    public function testFormatDateWithLocale()
+    {
+        $dateTime = new \DateTime();
+        // 2014-06-17
+        $dateTime->setTimestamp(1402987842);
+
+        $formatClass = new Format($this->request);
+
+        $render = $formatClass->formatDate(array(
+                'date' => $dateTime,
+                'locale' => ['fr_FR.UTF-8', 'fr_FR'],
+                'format' => '%e %B %Y'
+            ));
+
+        $this->assertEquals('17 juin 2014', $render);
+    }
+
     /**
      * test formatNumber without mandatory parameters
      *