1 files changed, 35 insertions, 11 deletions

diff --git a/tests/UtilsTest.php b/tests/UtilsTest.php
index b8f608b9..e70cc1ae 100644
--- a/tests/UtilsTest.php
+++ b/tests/UtilsTest.php
@@ -23,7 +23,12 @@ class UtilsTest extends PHPUnit_Framework_TestCase
 
     // Expected log date format
     protected static $dateFormat = 'Y/m/d H:i:s';
-    
+
+    /**
+     * @var string Save the current timezone.
+     */
+    protected static $defaultTimeZone;
+
 
     /**
      * Assign reference data
@@ -31,6 +36,17 @@ class UtilsTest extends PHPUnit_Framework_TestCase
     public static function setUpBeforeClass()
     {
         self::$sidHashes = ReferenceSessionIdHashes::getHashes();
+        self::$defaultTimeZone = date_default_timezone_get();
+        // Timezone without DST for test consistency
+        date_default_timezone_set('Africa/Nairobi');
+    }
+
+    /**
+     * Reset the timezone
+     */
+    public static function tearDownAfterClass()
+    {
+        date_default_timezone_set(self::$defaultTimeZone);
     }
 
     /**
@@ -286,20 +302,28 @@ class UtilsTest extends PHPUnit_Framework_TestCase
     /**
      * Test arrays_combine
      */
-    public function testArraysCombination()
+    public function testCartesianProductGenerator()
     {
         $arr = [['ab', 'cd'], ['ef', 'gh'], ['ij', 'kl'], ['m']];
         $expected = [
-            'abefijm',
-            'cdefijm',
-            'abghijm',
-            'cdghijm',
-            'abefklm',
-            'cdefklm',
-            'abghklm',
-            'cdghklm',
+            ['ab', 'ef', 'ij', 'm'],
+            ['ab', 'ef', 'kl', 'm'],
+            ['ab', 'gh', 'ij', 'm'],
+            ['ab', 'gh', 'kl', 'm'],
+            ['cd', 'ef', 'ij', 'm'],
+            ['cd', 'ef', 'kl', 'm'],
+            ['cd', 'gh', 'ij', 'm'],
+            ['cd', 'gh', 'kl', 'm'],
         ];
-        $this->assertEquals($expected, arrays_combination($arr));
+        $this->assertEquals($expected, iterator_to_array(cartesian_product_generator($arr)));
     }
 
+    /**
+     * Test date_format() with invalid parameter.
+     */
+    public function testDateFormatInvalid()
+    {
+        $this->assertFalse(format_date([]));
+        $this->assertFalse(format_date(null));
+    }
 }