From 5f6c2be6ae80989b8ea217f0c956921286ea5f7f Mon Sep 17 00:00:00 2001
From: Lukas Scharmer <lscharmer@databay.de>
Date: Mon, 25 Oct 2021 16:39:05 +0200
Subject: [PATCH 1/2] Create new array shuffled flow based on the Refinery.
 Refactor old shuffle to use the new way

---
 Modules/Test/classes/class.ilObjTestGUI.php   |  3 +-
 .../classes/class.ilTestPlayerAbstractGUI.php | 18 ++--
 Modules/Test/test/ilTestBaseTestCase.php      |  9 ++
 .../ilTestPlayerDynamicQuestionSetGUITest.php |  1 +
 Modules/Test/test/ilTestPlayerFactoryTest.php |  1 +
 .../ilTestPlayerFixedQuestionSetGUITest.php   |  1 +
 .../ilTestPlayerRandomQuestionSetGUITest.php  |  1 +
 .../classes/class.assClozeGap.php             | 12 ++-
 .../classes/class.assClozeTest.php            |  9 +-
 .../classes/class.assClozeTestGUI.php         | 15 ++-
 .../classes/class.assKprimChoiceGUI.php       |  2 +-
 .../classes/class.assMatchingQuestion.php     | 20 ++--
 .../classes/class.assMatchingQuestionGUI.php  | 24 ++---
 .../classes/class.assMultipleChoiceGUI.php    |  2 +-
 .../classes/class.assOrderingHorizontal.php   |  2 +-
 .../classes/class.assOrderingQuestion.php     |  6 +-
 .../classes/class.assQuestion.php             | 12 ++-
 .../classes/class.assSingleChoiceGUI.php      |  2 +-
 .../classes/class.ilAssQuestionPreviewGUI.php | 22 +++--
 .../classes/class.ilObjQuestionPoolGUI.php    |  3 +-
 .../export/qti12/class.assClozeTestExport.php | 19 +++-
 .../feedback/class.ilAssClozeTestFeedback.php | 27 ++++--
 .../ilAssLacCompositeValidator.php            |  9 +-
 .../TestQuestionPool/test/assBaseTestCase.php |  6 ++
 .../TestQuestionPool/test/assClozeGapTest.php | 93 +++++++++++--------
 .../test/assClozeSelectGapTest.php            | 30 ++++--
 .../classes/class.ilArrayElementShuffler.php  | 64 -------------
 .../class.ilBaseRandomElementProvider.php     | 32 -------
 ...ss.ilDeterministicArrayElementProvider.php | 22 -----
 ...interface.ilRandomArrayElementProvider.php | 19 ----
 .../test/RandomizationStrategiesTest.php      | 71 --------------
 src/Refinery/Effect/Effect.php                | 19 ++++
 src/Refinery/Effect/IdentityEffect.php        | 18 ++++
 .../Transformation/LiftTransformation.php     | 60 ++++++++++++
 src/Refinery/Factory.php                      |  6 ++
 src/Refinery/Random/Effect/ShuffleEffect.php  | 29 ++++++
 src/Refinery/Random/Group.php                 | 34 +++++++
 src/Refinery/Random/Seed/GivenSeed.php        | 26 ++++++
 src/Refinery/Random/Seed/RandomSeed.php       | 22 +++++
 src/Refinery/Random/Seed/Seed.php             | 12 +++
 .../Transformation/ShuffleTransformation.php  | 41 ++++++++
 .../Transformation/LiftTransformationTest.php | 63 +++++++++++++
 tests/Refinery/FactoryTest.php                |  8 +-
 .../Refinery/Random/Effect/ShuffleEffect.php  | 21 +++++
 tests/Refinery/Random/GroupTest.php           | 40 ++++++++
 .../ShuffleTransformationTest.php             | 37 ++++++++
 46 files changed, 663 insertions(+), 330 deletions(-)
 delete mode 100644 Services/Randomization/classes/class.ilArrayElementShuffler.php
 delete mode 100644 Services/Randomization/classes/class.ilBaseRandomElementProvider.php
 delete mode 100644 Services/Randomization/classes/class.ilDeterministicArrayElementProvider.php
 delete mode 100644 Services/Randomization/interfaces/interface.ilRandomArrayElementProvider.php
 delete mode 100644 Services/Randomization/test/RandomizationStrategiesTest.php
 create mode 100644 src/Refinery/Effect/Effect.php
 create mode 100644 src/Refinery/Effect/IdentityEffect.php
 create mode 100644 src/Refinery/Effect/Transformation/LiftTransformation.php
 create mode 100644 src/Refinery/Random/Effect/ShuffleEffect.php
 create mode 100644 src/Refinery/Random/Group.php
 create mode 100644 src/Refinery/Random/Seed/GivenSeed.php
 create mode 100644 src/Refinery/Random/Seed/RandomSeed.php
 create mode 100644 src/Refinery/Random/Seed/Seed.php
 create mode 100644 src/Refinery/Random/Transformation/ShuffleTransformation.php
 create mode 100644 tests/Refinery/Effect/Transformation/LiftTransformationTest.php
 create mode 100644 tests/Refinery/Random/Effect/ShuffleEffect.php
 create mode 100644 tests/Refinery/Random/GroupTest.php
 create mode 100644 tests/Refinery/Random/Transformation/ShuffleTransformationTest.php

diff --git a/Modules/Test/classes/class.ilObjTestGUI.php b/Modules/Test/classes/class.ilObjTestGUI.php
index 5d63a28e3f4f..da18c358b3e5 100755
--- a/Modules/Test/classes/class.ilObjTestGUI.php
+++ b/Modules/Test/classes/class.ilObjTestGUI.php
@@ -156,6 +156,7 @@ public function executeCommand()
         $tree = $DIC['tree'];
         $ilias = $DIC['ilias'];
         $ilUser = $DIC['ilUser'];
+        $randomGroup = $DIC->refinery()->random();
 
         $cmd = $this->ctrl->getCmd("infoScreen");
 
@@ -659,7 +660,7 @@ public function executeCommand()
                 $this->ctrl->saveParameter($this, "q_id");
 
                 require_once 'Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php';
-                $gui = new ilAssQuestionPreviewGUI($this->ctrl, $this->tabs_gui, $this->tpl, $this->lng, $ilDB, $ilUser);
+                $gui = new ilAssQuestionPreviewGUI($this->ctrl, $this->tabs_gui, $this->tpl, $this->lng, $ilDB, $ilUser, $randomGroup);
 
                 $gui->initQuestion($this->fetchAuthoringQuestionIdParameter(), $this->object->getId());
                 $gui->initPreviewSettings($this->object->getRefId());
diff --git a/Modules/Test/classes/class.ilTestPlayerAbstractGUI.php b/Modules/Test/classes/class.ilTestPlayerAbstractGUI.php
index 3aa628102c43..59f38c1960eb 100755
--- a/Modules/Test/classes/class.ilTestPlayerAbstractGUI.php
+++ b/Modules/Test/classes/class.ilTestPlayerAbstractGUI.php
@@ -1,6 +1,11 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Transformation;
+use ILIAS\Refinery\Random\Seed\RandomSeed;
+use ILIAS\Refinery\Random\Seed\GivenSeed;
+use ILIAS\Refinery\Random\Group as RandomGroup;
+
 require_once './Modules/Test/classes/inc.AssessmentConstants.php';
 require_once './Modules/Test/classes/class.ilTestPlayerCommands.php';
 require_once './Modules/Test/classes/class.ilTestServiceGUI.php';
@@ -61,6 +66,8 @@ abstract class ilTestPlayerAbstractGUI extends ilTestServiceGUI
      */
     protected $testSequence = null;
 
+    private RandomGroup $randomGroup;
+
     /**
     * ilTestOutputGUI constructor
     *
@@ -81,6 +88,7 @@ public function __construct($a_object)
         $this->processLocker = null;
         $this->testSession = null;
         $this->assSettings = null;
+        $this->randomGroup = $DIC->refinery()->random();
     }
 
     protected function checkReadAccess()
@@ -2534,17 +2542,13 @@ protected function initTestQuestionConfig(assQuestion $questionOBJ)
     
     /**
      * @param $questionId
-     * @return ilArrayElementShuffler
+     * @return Transformation
      */
     protected function buildQuestionAnswerShuffler($questionId)
     {
-        require_once 'Services/Randomization/classes/class.ilArrayElementShuffler.php';
-        $shuffler = new ilArrayElementShuffler();
-        
         $fixedSeed = $this->buildFixedShufflerSeed($questionId);
-        $shuffler->setSeed($fixedSeed);
-        
-        return $shuffler;
+
+        return $this->randomGroup->shuffleArray(new GivenSeed($fixedSeed));
     }
 
     /**
diff --git a/Modules/Test/test/ilTestBaseTestCase.php b/Modules/Test/test/ilTestBaseTestCase.php
index b6a7b976bf0b..5acb4a6e4fff 100644
--- a/Modules/Test/test/ilTestBaseTestCase.php
+++ b/Modules/Test/test/ilTestBaseTestCase.php
@@ -9,6 +9,8 @@
 use ILIAS\Filesystem\Filesystems;
 use ILIAS\HTTP\Services;
 use ILIAS\UI\Implementation\Factory;
+use ILIAS\Refinery\Factory as RefineryFactory;
+use ILIAS\Refinery\Random\Group as RandomGroup;
 
 /**
  * Class ilTestBaseClass
@@ -216,4 +218,11 @@ protected function addGlobal_uiRenderer() : void
     {
         $this->setGlobalVariable("ui.renderer", $this->createMock(ILIAS\UI\Implementation\DefaultRenderer::class));
     }
+
+    protected function addGlobal_refinery() : void
+    {
+        $refineryMock = $this->getMockBuilder(RefineryFactory::class)->disableOriginalConstructor()->getMock();
+        $refineryMock->expects(self::any())->method('random')->willReturn($this->getMockBuilder(RandomGroup::class)->getMock());
+        $this->setGlobalVariable("refinery", $refineryMock);
+    }
 }
diff --git a/Modules/Test/test/ilTestPlayerDynamicQuestionSetGUITest.php b/Modules/Test/test/ilTestPlayerDynamicQuestionSetGUITest.php
index c7df7803149d..3799eac0ecbe 100644
--- a/Modules/Test/test/ilTestPlayerDynamicQuestionSetGUITest.php
+++ b/Modules/Test/test/ilTestPlayerDynamicQuestionSetGUITest.php
@@ -25,6 +25,7 @@ protected function setUp() : void
         $this->addGlobal_ilObjDataCache();
         $this->addGlobal_rbacsystem();
         $this->addGlobal_ilUser();
+        $this->addGlobal_refinery();
 
         $_GET["ref_id"] = 2;
 
diff --git a/Modules/Test/test/ilTestPlayerFactoryTest.php b/Modules/Test/test/ilTestPlayerFactoryTest.php
index 36bdf681f2da..a1ff8d6ae6a9 100644
--- a/Modules/Test/test/ilTestPlayerFactoryTest.php
+++ b/Modules/Test/test/ilTestPlayerFactoryTest.php
@@ -40,6 +40,7 @@ public function testGetPlayerGUI() : void
         $this->addGlobal_ilObjDataCache();
         $_GET["ref_id"] = 2;
         $this->addGlobal_rbacsystem();
+        $this->addGlobal_refinery();
 
         $objTest = new ilObjTest();
 
diff --git a/Modules/Test/test/ilTestPlayerFixedQuestionSetGUITest.php b/Modules/Test/test/ilTestPlayerFixedQuestionSetGUITest.php
index 7112fe76b3d5..6a9c5ff64f66 100644
--- a/Modules/Test/test/ilTestPlayerFixedQuestionSetGUITest.php
+++ b/Modules/Test/test/ilTestPlayerFixedQuestionSetGUITest.php
@@ -27,6 +27,7 @@ protected function setUp() : void
         $this->addGlobal_ilObjDataCache();
         $this->addGlobal_rbacsystem();
         $this->addGlobal_ilUser();
+        $this->addGlobal_refinery();
 
         $this->testObj = new ilTestPlayerFixedQuestionSetGUI(
             $this->createMock(ilObjTest::class)
diff --git a/Modules/Test/test/ilTestPlayerRandomQuestionSetGUITest.php b/Modules/Test/test/ilTestPlayerRandomQuestionSetGUITest.php
index cb5694e430bd..d9d6559067a8 100644
--- a/Modules/Test/test/ilTestPlayerRandomQuestionSetGUITest.php
+++ b/Modules/Test/test/ilTestPlayerRandomQuestionSetGUITest.php
@@ -25,6 +25,7 @@ protected function setUp() : void
         $this->addGlobal_ilObjDataCache();
         $this->addGlobal_rbacsystem();
         $this->addGlobal_ilUser();
+        $this->addGlobal_refinery();
 
         $_GET["ref_id"] = "0";
 
diff --git a/Modules/TestQuestionPool/classes/class.assClozeGap.php b/Modules/TestQuestionPool/classes/class.assClozeGap.php
index 5c2f410e09a8..63b61f54f4b2 100755
--- a/Modules/TestQuestionPool/classes/class.assClozeGap.php
+++ b/Modules/TestQuestionPool/classes/class.assClozeGap.php
@@ -1,6 +1,8 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Transformation;
+
 include_once "./Modules/Test/classes/inc.AssessmentConstants.php";
 
 /**
@@ -85,13 +87,13 @@ public function setType($a_type = 0)
     /**
      * Gets the items of a cloze gap
      *
-     * @param ilRandomArrayElementProvider $shuffler
+     * @param Transformation $shuffler
      * @return assAnswerCloze[] The list of items
      */
-    public function getItems(ilRandomArrayElementProvider $shuffler)
+    public function getItems(Transformation $shuffler) : array
     {
         if ($this->getShuffle()) {
-            return $shuffler->shuffle($this->items);
+            return $shuffler->transform($this->items)->value();
         }
         
         return $this->items;
@@ -334,11 +336,11 @@ public function getBestSolutionIndexes()
     }
 
     /**
-     * @param ilRandomArrayElementProvider $shuffler
+     * @param Transformation $shuffler
      * @param null | array $combinations
      * @return string
      */
-    public function getBestSolutionOutput(ilRandomArrayElementProvider $shuffler, $combinations = null)
+    public function getBestSolutionOutput(Transformation $shuffler, $combinations = null)
     {
         global $DIC;
         $lng = $DIC['lng'];
diff --git a/Modules/TestQuestionPool/classes/class.assClozeTest.php b/Modules/TestQuestionPool/classes/class.assClozeTest.php
index 98bc43b08025..b2e590bd6eb1 100755
--- a/Modules/TestQuestionPool/classes/class.assClozeTest.php
+++ b/Modules/TestQuestionPool/classes/class.assClozeTest.php
@@ -1,6 +1,8 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+
 require_once './Modules/TestQuestionPool/classes/class.assQuestion.php';
 require_once './Modules/Test/classes/inc.AssessmentConstants.php';
 require_once './Modules/TestQuestionPool/classes/class.assClozeGapCombination.php';
@@ -101,6 +103,8 @@ class assClozeTest extends assQuestion implements ilObjQuestionScoringAdjustable
 
     protected $feedbackMode = ilAssClozeTestFeedback::FB_MODE_GAP_QUESTION;
 
+    private RandomGroup $randomGroup;
+
     /**
      * assClozeTest constructor
      *
@@ -121,6 +125,8 @@ public function __construct(
         $owner = -1,
         $question = ""
     ) {
+        global $DIC;
+
         parent::__construct($title, $comment, $author, $owner, $question);
         $this->start_tag = "[gap]";
         $this->end_tag = "[/gap]";
@@ -130,6 +136,7 @@ public function __construct(
         $this->identical_scoring = 1;
         $this->gap_combinations_exists = false;
         $this->gap_combinations = array();
+        $this->randomGroup = $DIC->refinery()->random();
     }
 
     /**
@@ -2010,7 +2017,7 @@ public function isAddableAnswerOptionValue(int $qIndex, string $answerOptionValu
             return false;
         }
 
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $item) {
+        foreach ($gap->getItems($this->randomGroup->dontShuffle()) as $item) {
             if ($item->getAnswertext() == $answerOptionValue) {
                 return false;
             }
diff --git a/Modules/TestQuestionPool/classes/class.assClozeTestGUI.php b/Modules/TestQuestionPool/classes/class.assClozeTestGUI.php
index 803c5170eca7..1642fef8b0c5 100755
--- a/Modules/TestQuestionPool/classes/class.assClozeTestGUI.php
+++ b/Modules/TestQuestionPool/classes/class.assClozeTestGUI.php
@@ -1,6 +1,9 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+use ILIAS\Refinery\Random\RandomSeed;
+
 require_once './Modules/TestQuestionPool/classes/class.assQuestionGUI.php';
 require_once './Modules/TestQuestionPool/interfaces/interface.ilGuiQuestionScoringAdjustable.php';
 require_once './Modules/TestQuestionPool/interfaces/interface.ilGuiAnswerScoringAdjustable.php';
@@ -29,6 +32,8 @@ class assClozeTestGUI extends assQuestionGUI implements ilGuiQuestionScoringAdju
     */
     private $gapIndex;
 
+    private RandomGroup $randomGroup;
+
     /**
     * assClozeTestGUI constructor
     *
@@ -36,12 +41,16 @@ class assClozeTestGUI extends assQuestionGUI implements ilGuiQuestionScoringAdju
     */
     public function __construct($id = -1)
     {
+        global $DIC;
+
         parent::__construct();
         include_once "./Modules/TestQuestionPool/classes/class.assClozeTest.php";
         $this->object = new assClozeTest();
         if ($id >= 0) {
             $this->object->loadFromDb($id);
         }
+
+        $this->randomGroup = $DIC->refinery()->random();
     }
 
     public function getCommand($cmd)
@@ -1432,7 +1441,7 @@ public function getAggregatedAnswersView($relevant_answers)
 
             if ($gap->type == CLOZE_TEXT) {
                 $present_elements = array();
-                foreach ($gap->getItems(new ilArrayElementShuffler()) as $item) {
+                foreach ($gap->getItems($this->randomGroup->shuffleArray(new RandomSeed())) as $item) {
                     /** @var assAnswerCloze $item */
                     $present_elements[] = $item->getAnswertext();
                 }
@@ -1577,7 +1586,7 @@ protected function getAnswerTextLabel($gapIndex, $answer)
 
             case CLOZE_SELECT:
 
-                $items = $gap->getItems(new ilDeterministicArrayElementProvider());
+                $items = $gap->getItems($this->randomGroup->dontShuffle());
                 return $items[$answer]->getAnswertext();
         }
     }
@@ -1593,7 +1602,7 @@ protected function completeAddAnswerAction($answers, $questionIndex)
         foreach ($answers as $key => $ans) {
             $found = false;
 
-            foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $item) {
+            foreach ($gap->getItems($this->randomGroup->dontShuffle()) as $item) {
                 if ($ans['answer'] !== $item->getAnswerText()) {
                     continue;
                 }
diff --git a/Modules/TestQuestionPool/classes/class.assKprimChoiceGUI.php b/Modules/TestQuestionPool/classes/class.assKprimChoiceGUI.php
index b3f14e67cc18..5ea4171e36fe 100644
--- a/Modules/TestQuestionPool/classes/class.assKprimChoiceGUI.php
+++ b/Modules/TestQuestionPool/classes/class.assKprimChoiceGUI.php
@@ -707,7 +707,7 @@ protected function getParticipantsAnswerKeySequence()
         $choiceKeys = array_keys($this->object->getAnswers());
 
         if ($this->object->isShuffleAnswersEnabled()) {
-            $choiceKeys = $this->object->getShuffler()->shuffle($choiceKeys);
+            $choiceKeys = $this->object->getShuffler()->transform($choiceKeys)->value();
         }
 
         return $choiceKeys;
diff --git a/Modules/TestQuestionPool/classes/class.assMatchingQuestion.php b/Modules/TestQuestionPool/classes/class.assMatchingQuestion.php
index 68a179179cd0..92e1960582e9 100755
--- a/Modules/TestQuestionPool/classes/class.assMatchingQuestion.php
+++ b/Modules/TestQuestionPool/classes/class.assMatchingQuestion.php
@@ -1,6 +1,9 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+use ILIAS\Refinery\Random\Seed\RandomSeed;
+
 require_once './Modules/TestQuestionPool/classes/class.assQuestion.php';
 require_once './Modules/Test/classes/inc.AssessmentConstants.php';
 require_once './Modules/TestQuestionPool/interfaces/interface.ilObjQuestionScoringAdjustable.php';
@@ -68,6 +71,8 @@ class assMatchingQuestion extends assQuestion implements ilObjQuestionScoringAdj
 
     protected $matchingMode = self::MATCHING_MODE_1_ON_1;
 
+    private RandomGroup $randomGroup;
+
     /**
      * assMatchingQuestion constructor
      *
@@ -90,11 +95,14 @@ public function __construct(
         $question = "",
         $matching_type = MT_TERMS_DEFINITIONS
     ) {
+        global $DIC;
+
         parent::__construct($title, $comment, $author, $owner, $question);
         $this->matchingpairs = array();
         $this->matching_type = $matching_type;
         $this->terms = array();
         $this->definitions = array();
+        $this->randomGroup = $DIC->refinery()->random();
     }
 
     /**
@@ -1380,14 +1388,11 @@ public function toJSON() : string
             'onenotcorrect' => $this->formatSAQuestion($this->feedbackOBJ->getGenericFeedbackTestPresentation($this->getId(), false)),
             'allcorrect' => $this->formatSAQuestion($this->feedbackOBJ->getGenericFeedbackTestPresentation($this->getId(), true))
         );
-        
-        require_once 'Services/Randomization/classes/class.ilArrayElementShuffler.php';
-        $this->setShuffler(new ilArrayElementShuffler());
-        $seed = $this->getShuffler()->getSeed();
+
+        $this->setShuffler($this->randomGroup->shuffleArray(new RandomSeed()));
         
         $terms = array();
-        $this->getShuffler()->setSeed($this->getShuffler()->buildSeedFromString($seed . 'terms'));
-        foreach ($this->getShuffler()->shuffle($this->getTerms()) as $term) {
+        foreach ($this->getShuffler()->transform($this->getTerms())->value() as $term) {
             $terms[] = array(
                 "text" => $this->formatSAQuestion($term->text),
                 "id" => (int) $this->getId() . $term->identifier
@@ -1403,8 +1408,7 @@ public function toJSON() : string
         // when the second one (the copy) is answered.
 
         $definitions = array();
-        $this->getShuffler()->setSeed($this->getShuffler()->buildSeedFromString($seed . 'definitions'));
-        foreach ($this->getShuffler()->shuffle($this->getDefinitions()) as $def) {
+        foreach ($this->getShuffler()->transform($this->getDefinitions())->value() as $def) {
             $definitions[] = array(
                 "text" => $this->formatSAQuestion((string) $def->text),
                 "id" => (int) $this->getId() . $def->identifier
diff --git a/Modules/TestQuestionPool/classes/class.assMatchingQuestionGUI.php b/Modules/TestQuestionPool/classes/class.assMatchingQuestionGUI.php
index eb46dc5d0c63..d3d73b34d6c4 100755
--- a/Modules/TestQuestionPool/classes/class.assMatchingQuestionGUI.php
+++ b/Modules/TestQuestionPool/classes/class.assMatchingQuestionGUI.php
@@ -632,18 +632,14 @@ public function getPreview($show_question_only = false, $showInlineFeedback = fa
         $definitions = $this->object->getDefinitions();
         switch ($this->object->getShuffle()) {
             case 1:
-                $seed = $this->object->getShuffler()->getSeed();
-                $this->object->getShuffler()->setSeed($seed . '1');
-                $terms = $this->object->getShuffler()->shuffle($terms);
-                $this->object->getShuffler()->setSeed($seed . '2');
-                $definitions = $this->object->getShuffler()->shuffle($definitions);
-                $this->object->getShuffler()->setSeed($seed);
+                $terms = $this->object->getShuffler()->transform($terms)->value();
+                $definitions = $this->object->getShuffler()->transform($definitions)->value();
                 break;
             case 2:
-                $terms = $this->object->getShuffler()->shuffle($terms);
+                $terms = $this->object->getShuffler()->transform($terms)->value();
                 break;
             case 3:
-                $definitions = $this->object->getShuffler()->shuffle($definitions);
+                $definitions = $this->object->getShuffler()->transform($definitions)->value();
                 break;
         }
 
@@ -828,25 +824,21 @@ public function getTestOutput($active_id, $pass, $is_postponed = false, $user_po
         $definitions = $this->object->getDefinitions();
         switch ($this->object->getShuffle()) {
             case 1:
-                $seed = $this->object->getShuffler()->getSeed();
-                $this->object->getShuffler()->setSeed($seed . '1');
-                $terms = $this->object->getShuffler()->shuffle($terms);
+                $terms = $this->object->getShuffler()->transform($terms)->value();
                 if (count($solutions)) {
                     $definitions = $this->sortDefinitionsBySolution($solutions, $definitions);
                 } else {
-                    $this->object->getShuffler()->setSeed($seed . '2');
-                    $definitions = $this->object->getShuffler()->shuffle($definitions);
+                    $definitions = $this->object->getShuffler()->transform($definitions)->value();
                 }
-                $this->object->getShuffler()->setSeed($seed);
                 break;
             case 2:
-                $terms = $this->object->getShuffler()->shuffle($terms);
+                $terms = $this->object->getShuffler()->transform($terms)->value();
                 break;
             case 3:
                 if (count($solutions)) {
                     $definitions = $this->sortDefinitionsBySolution($solutions, $definitions);
                 } else {
-                    $definitions = $this->object->getShuffler()->shuffle($definitions);
+                    $definitions = $this->object->getShuffler()->transform($definitions)->value();
                 }
                 break;
         }
diff --git a/Modules/TestQuestionPool/classes/class.assMultipleChoiceGUI.php b/Modules/TestQuestionPool/classes/class.assMultipleChoiceGUI.php
index 03ad9ca04c02..5fd6a572ba74 100755
--- a/Modules/TestQuestionPool/classes/class.assMultipleChoiceGUI.php
+++ b/Modules/TestQuestionPool/classes/class.assMultipleChoiceGUI.php
@@ -737,7 +737,7 @@ public function getChoiceKeys()
         $choiceKeys = array_keys($this->object->answers);
 
         if ($this->object->getShuffle()) {
-            $choiceKeys = $this->object->getShuffler()->shuffle($choiceKeys);
+            $choiceKeys = $this->object->getShuffler()->transform($choiceKeys)->value();
         }
 
         return $choiceKeys;
diff --git a/Modules/TestQuestionPool/classes/class.assOrderingHorizontal.php b/Modules/TestQuestionPool/classes/class.assOrderingHorizontal.php
index 1f8555ba1616..a1f3b46c446a 100644
--- a/Modules/TestQuestionPool/classes/class.assOrderingHorizontal.php
+++ b/Modules/TestQuestionPool/classes/class.assOrderingHorizontal.php
@@ -524,7 +524,7 @@ public function getOrderingElements()
     public function getRandomOrderingElements()
     {
         $elements = $this->getOrderingElements();
-        $elements = $this->getShuffler()->shuffle($elements);
+        $elements = $this->getShuffler()->transform($elements)->value();
         return $elements;
     }
     
diff --git a/Modules/TestQuestionPool/classes/class.assOrderingQuestion.php b/Modules/TestQuestionPool/classes/class.assOrderingQuestion.php
index bf1448de988a..d3a7836a038c 100755
--- a/Modules/TestQuestionPool/classes/class.assOrderingQuestion.php
+++ b/Modules/TestQuestionPool/classes/class.assOrderingQuestion.php
@@ -544,9 +544,9 @@ public function getSolutionOrderingElementList($indexedSolutionValues)
      */
     public function getShuffledOrderingElementList()
     {
-        $shuffledRandomIdentifierIndex = $this->getShuffler()->shuffle(
+        $shuffledRandomIdentifierIndex = $this->getShuffler()->transform(
             $this->getOrderingElementList()->getRandomIdentifierIndex()
-        );
+        )->value();
         
         $shuffledElementList = $this->getOrderingElementList()->getClone();
         $shuffledElementList->reorderByRandomIdentifiers($shuffledRandomIdentifierIndex);
@@ -1163,7 +1163,7 @@ public function toJSON() : string
             $answers[$counter] = $orderingElement->getContent();
             $counter++;
         }
-        $answers = $this->getShuffler()->shuffle($answers);
+        $answers = $this->getShuffler()->transform($answers)->value();
         $arr = array();
         foreach ($answers as $order => $answer) {
             array_push($arr, array(
diff --git a/Modules/TestQuestionPool/classes/class.assQuestion.php b/Modules/TestQuestionPool/classes/class.assQuestion.php
index 08cace667609..6ebaf63e4cb7 100755
--- a/Modules/TestQuestionPool/classes/class.assQuestion.php
+++ b/Modules/TestQuestionPool/classes/class.assQuestion.php
@@ -1,6 +1,8 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Transformation;
+
 require_once './Modules/Test/classes/inc.AssessmentConstants.php';
 require_once dirname(__DIR__) . '../../../libs/composer/vendor/autoload.php';
 
@@ -153,7 +155,7 @@ abstract class assQuestion
     
     protected $lastChange;
 
-    protected \ilRandomArrayElementProvider $shuffler;
+    protected Transformation $shuffler;
 
     private bool $obligationsToBeConsidered = false;
 
@@ -166,7 +168,7 @@ abstract class assQuestion
         'image/png' => array('png'),
         'image/gif' => array('gif')
     );
-    
+
     /**
      * assQuestion constructor
      */
@@ -212,7 +214,7 @@ public function __construct(
 
         $this->questionActionCmd = 'handleQuestionAction';
 
-        $this->shuffler = new ilDeterministicArrayElementProvider();
+        $this->shuffler = $DIC->refinery()->random()->dontShuffle();
         $this->lifecycle = ilAssQuestionLifecycle::getDraftInstance();
     }
     
@@ -360,12 +362,12 @@ public static function getAllowedImageMaterialFileExtensions() : array
         return array_unique($extensions);
     }
 
-    public function getShuffler() : ilRandomArrayElementProvider
+    public function getShuffler() : Transformation
     {
         return $this->shuffler;
     }
 
-    public function setShuffler(ilRandomArrayElementProvider $shuffler) : void
+    public function setShuffler(Transformation $shuffler) : void
     {
         $this->shuffler = $shuffler;
     }
diff --git a/Modules/TestQuestionPool/classes/class.assSingleChoiceGUI.php b/Modules/TestQuestionPool/classes/class.assSingleChoiceGUI.php
index 6bd9c78d2774..6e6c435b8acd 100755
--- a/Modules/TestQuestionPool/classes/class.assSingleChoiceGUI.php
+++ b/Modules/TestQuestionPool/classes/class.assSingleChoiceGUI.php
@@ -610,7 +610,7 @@ public function getChoiceKeys()
         $choiceKeys = array_keys($this->object->answers);
         
         if ($this->object->getShuffle()) {
-            $choiceKeys = $this->object->getShuffler()->shuffle($choiceKeys);
+            $choiceKeys = $this->object->getShuffler()->transform($choiceKeys)->value();
         }
         
         return $choiceKeys;
diff --git a/Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php b/Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php
index 6af31ee05dc3..471672fb1a47 100644
--- a/Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php
+++ b/Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php
@@ -1,6 +1,10 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+use ILIAS\Refinery\Random\Seed\RandomSeed;
+use ILIAS\Refinery\Random\Seed\GivenSeed;
+use ILIAS\Refinery\Transformation;
 
 /**
  * @author		Björn Heyser <bheyser@databay.de>
@@ -82,8 +86,10 @@ class ilAssQuestionPreviewGUI
      * @var ilAssQuestionPreviewHintTracking
      */
     protected $hintTracking;
+
+    private RandomGroup $randomGroup;
     
-    public function __construct(ilCtrl $ctrl, ilTabsGUI $tabs, ilGlobalTemplateInterface $tpl, ilLanguage $lng, ilDBInterface $db, ilObjUser $user)
+    public function __construct(ilCtrl $ctrl, ilTabsGUI $tabs, ilGlobalTemplateInterface $tpl, ilLanguage $lng, ilDBInterface $db, ilObjUser $user, RandomGroup $randomGroup)
     {
         $this->ctrl = $ctrl;
         $this->tabs = $tabs;
@@ -91,6 +97,7 @@ public function __construct(ilCtrl $ctrl, ilTabsGUI $tabs, ilGlobalTemplateInter
         $this->lng = $lng;
         $this->db = $db;
         $this->user = $user;
+        $this->randomGroup = $randomGroup;
     }
 
     public function initQuestion($questionId, $parentObjId)
@@ -543,20 +550,15 @@ public function gatewayShowHintListCmd()
     }
 
     /**
-     * @return ilArrayElementShuffler
+     * @return Transformation
      */
     private function getQuestionAnswerShuffler()
     {
-        require_once 'Services/Randomization/classes/class.ilArrayElementShuffler.php';
-        $shuffler = new ilArrayElementShuffler();
-        
         if (!$this->previewSession->randomizerSeedExists()) {
-            $this->previewSession->setRandomizerSeed($shuffler->buildRandomSeed());
+            $this->previewSession->setRandomizerSeed((new RandomSeed())->createSeed());
         }
-        
-        $shuffler->setSeed($this->previewSession->getRandomizerSeed());
-        
-        return $shuffler;
+
+        return $this->randomGroup->shuffleArray(new GivenSeed($this->previewSession->getRandomizerSeed()));
     }
     
     protected function populateNotesPanel(ilTemplate $tpl, $notesPanelHTML)
diff --git a/Modules/TestQuestionPool/classes/class.ilObjQuestionPoolGUI.php b/Modules/TestQuestionPool/classes/class.ilObjQuestionPoolGUI.php
index d4f5be7a6a85..624d20c5b1be 100755
--- a/Modules/TestQuestionPool/classes/class.ilObjQuestionPoolGUI.php
+++ b/Modules/TestQuestionPool/classes/class.ilObjQuestionPoolGUI.php
@@ -92,6 +92,7 @@ public function executeCommand()
         $ilDB = $DIC['ilDB'];
         $ilPluginAdmin = $DIC['ilPluginAdmin'];
         $ilias = $DIC['ilias'];
+        $randomGroup = $DIC->refinery()->random();
         
         $writeAccess = $ilAccess->checkAccess("write", "", $_GET["ref_id"]);
         
@@ -162,7 +163,7 @@ public function executeCommand()
                 $this->ctrl->saveParameter($this, "q_id");
 
                 require_once 'Modules/TestQuestionPool/classes/class.ilAssQuestionPreviewGUI.php';
-                $gui = new ilAssQuestionPreviewGUI($this->ctrl, $this->tabs_gui, $this->tpl, $this->lng, $ilDB, $ilUser);
+                $gui = new ilAssQuestionPreviewGUI($this->ctrl, $this->tabs_gui, $this->tpl, $this->lng, $ilDB, $ilUser, $randomGroup);
                 
                 $gui->initQuestion((int) $_GET['q_id'], $this->object->getId());
                 $gui->initPreviewSettings($this->object->getRefId());
diff --git a/Modules/TestQuestionPool/classes/export/qti12/class.assClozeTestExport.php b/Modules/TestQuestionPool/classes/export/qti12/class.assClozeTestExport.php
index 3635cb9c76b6..789a06d4f4d1 100644
--- a/Modules/TestQuestionPool/classes/export/qti12/class.assClozeTestExport.php
+++ b/Modules/TestQuestionPool/classes/export/qti12/class.assClozeTestExport.php
@@ -1,6 +1,8 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+
 include_once "./Modules/TestQuestionPool/classes/export/qti12/class.assQuestionExport.php";
 
 /**
@@ -14,6 +16,17 @@
 */
 class assClozeTestExport extends assQuestionExport
 {
+    private RandomGroup $randomGroup;
+
+    public function __construct($object)
+    {
+        global $DIC;
+
+        parent::__construct($object);
+
+        $this->randomGroup = $DIC->refinery()->random();
+    }
+
     /**
     * Returns a QTI xml representation of the question
     *
@@ -144,7 +157,7 @@ public function toXML($a_include_header = true, $a_include_binary = true, $a_shu
                         $a_xml_writer->xmlStartTag("render_choice", $attrs);
 
                         // add answers
-                        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answeritem) {
+                        foreach ($gap->getItems($this->randomGroup->dontShuffle()) as $answeritem) {
                             $attrs = array(
                                 "ident" => $answeritem->getOrder()
                             );
@@ -249,7 +262,7 @@ public function toXML($a_include_header = true, $a_include_binary = true, $a_shu
             $gap = $this->object->getGap($i);
             switch ($gap->getType()) {
                 case CLOZE_SELECT:
-                    foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answer) {
+                    foreach ($gap->getItems($this->randomGroup->dontShuffle()) as $answer) {
                         $attrs = array(
                             "continue" => "Yes"
                         );
@@ -280,7 +293,7 @@ public function toXML($a_include_header = true, $a_include_binary = true, $a_shu
                     break;
                 case CLOZE_NUMERIC:
                 case CLOZE_TEXT:
-                    foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answer) {
+                    foreach ($gap->getItems($this->randomGroup->dontShuffle()) as $answer) {
                         $attrs = array(
                             "continue" => "Yes"
                         );
diff --git a/Modules/TestQuestionPool/classes/feedback/class.ilAssClozeTestFeedback.php b/Modules/TestQuestionPool/classes/feedback/class.ilAssClozeTestFeedback.php
index b1fdf84bda26..eb352cdea876 100644
--- a/Modules/TestQuestionPool/classes/feedback/class.ilAssClozeTestFeedback.php
+++ b/Modules/TestQuestionPool/classes/feedback/class.ilAssClozeTestFeedback.php
@@ -1,6 +1,8 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+
 require_once 'Modules/TestQuestionPool/classes/feedback/class.ilAssMultiOptionQuestionFeedback.php';
 
 /**
@@ -46,7 +48,7 @@ protected function buildGapFeedbackLabel(int $gapIndex, assClozeGap $gap) : stri
     {
         $answers = array();
         
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $item) {
             $answers[] = '"' . $item->getAnswertext() . '"';
         }
         
@@ -191,7 +193,7 @@ protected function completeFormPropsForFeedbackModeGapAnswers(ilRadioOption $fbM
 
     protected function completeFbPropsForTextGap(ilRadioOption $fbModeOpt, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answerIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $answerIndex => $item) {
             $propertyLabel = $this->questionOBJ->prepareTextareaOutput(
                 $this->buildTextGapGivenAnswerFeedbackLabel($gapIndex, $item),
                 true
@@ -235,7 +237,7 @@ protected function completeFbPropsForTextGap(ilRadioOption $fbModeOpt, assClozeG
     
     protected function completeFbPropsForSelectGap(ilRadioOption $fbModeOpt, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $optIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $optIndex => $item) {
             $propertyLabel = $this->questionOBJ->prepareTextareaOutput(
                 $this->buildSelectGapOptionFeedbackLabel($gapIndex, $item),
                 true
@@ -397,7 +399,7 @@ protected function initFeedbackFieldsPerGapAnswers(ilPropertyFormGUI $form) : vo
     
     protected function initFbPropsForTextGap(ilPropertyFormGUI $form, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answerIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $answerIndex => $item) {
             $value = $this->getSpecificAnswerFeedbackFormValue($gapIndex, $answerIndex);
             $postVar = $this->buildPostVarForFbFieldPerGapAnswers($gapIndex, $answerIndex);
             $form->getItemByPostVar($postVar)->setValue($value);
@@ -414,7 +416,7 @@ protected function initFbPropsForTextGap(ilPropertyFormGUI $form, assClozeGap $g
     
     protected function initFbPropsForSelectGap(ilPropertyFormGUI $form, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $optIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $optIndex => $item) {
             $value = $this->getSpecificAnswerFeedbackFormValue($gapIndex, $optIndex);
             $postVar = $this->buildPostVarForFbFieldPerGapAnswers($gapIndex, $optIndex);
             $form->getItemByPostVar($postVar)->setValue($value);
@@ -514,7 +516,7 @@ protected function saveFeedbackFieldsPerGapAnswers(ilPropertyFormGUI $form) : vo
     
     protected function saveFbPropsForTextGap(ilPropertyFormGUI $form, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $answerIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $answerIndex => $item) {
             $postVar = $this->buildPostVarForFbFieldPerGapAnswers($gapIndex, $answerIndex);
             $value = $form->getItemByPostVar($postVar)->getValue();
             $this->saveSpecificAnswerFeedbackContent(
@@ -546,7 +548,7 @@ protected function saveFbPropsForTextGap(ilPropertyFormGUI $form, assClozeGap $g
     
     protected function saveFbPropsForSelectGap(ilPropertyFormGUI $form, assClozeGap $gap, int $gapIndex) : void
     {
-        foreach ($gap->getItems(new ilDeterministicArrayElementProvider()) as $optIndex => $item) {
+        foreach ($gap->getItems($this->randomGroup()->dontShuffle()) as $optIndex => $item) {
             $postVar = $this->buildPostVarForFbFieldPerGapAnswers($gapIndex, $optIndex);
             $value = $form->getItemByPostVar($postVar)->getValue();
             $this->saveSpecificAnswerFeedbackContent(
@@ -792,7 +794,7 @@ public function determineAnswerIndexForAnswerValue(assClozeGap $gap, int $answer
                     return self::FB_TEXT_GAP_EMPTY_INDEX;
                 }
 
-                $items = $gap->getItems(new ilDeterministicArrayElementProvider());
+                $items = $gap->getItems($this->randomGroup()->dontShuffle());
 
                 foreach ($items as $answerIndex => $answer) {
                     /* @var assAnswerCloze $answer */
@@ -821,7 +823,7 @@ public function determineAnswerIndexForAnswerValue(assClozeGap $gap, int $answer
 
                 /* @var assAnswerCloze $item */
 
-                $item = current($gap->getItems(new ilDeterministicArrayElementProvider()));
+                $item = current($gap->getItems($this->randomGroup()->dontShuffle()));
 
                 if ($answerValue == $item->getAnswertext()) {
                     return self::FB_NUMERIC_GAP_VALUE_HIT_INDEX;
@@ -850,4 +852,11 @@ public function determineAnswerIndexForAnswerValue(assClozeGap $gap, int $answer
                 //}
         }
     }
+
+    private function randomGroup() : RandomGroup
+    {
+        global $DIC;
+
+        return $DIC->refinery()->random();
+    }
 }
diff --git a/Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/ilAssLacCompositeValidator.php b/Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/ilAssLacCompositeValidator.php
index 6be3b700eb0f..c14c56f9fe97 100644
--- a/Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/ilAssLacCompositeValidator.php
+++ b/Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/ilAssLacCompositeValidator.php
@@ -1,5 +1,7 @@
 <?php
 
+use ILIAS\Refinery\Random\Group as RandomGroup;
+
 require_once "Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/Expressions/ilAssLacResultOfAnswerOfQuestionExpression.php";
 require_once "Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/Exception/ilAssLacExpressionNotSupportedByQuestion.php";
 require_once "Modules/TestQuestionPool/classes/questions/LogicalAnswerCompare/Exception/ilAssLacQuestionNotExist.php";
@@ -29,12 +31,17 @@ class ilAssLacCompositeValidator
      */
     protected $object_loader;
 
+    private RandomGroup $randomGroup;
+
     /**
      * @param ilAssLacQuestionProvider $object_loader
      */
     public function __construct($object_loader)
     {
+        global $DIC;
+
         $this->object_loader = $object_loader;
+        $this->randomGroup = $DIC->refinery()->random();
     }
 
     public function validate(ilAssLacAbstractComposite $composite)
@@ -240,6 +247,6 @@ private function checkOperatorExistForExpression($operators, $answer_expression,
     
     protected function getNonShuffler()
     {
-        return new ilDeterministicArrayElementProvider();
+        return $this->randomGroup->dontShuffle();
     }
 }
diff --git a/Modules/TestQuestionPool/test/assBaseTestCase.php b/Modules/TestQuestionPool/test/assBaseTestCase.php
index 7c1a2bfad56a..58d091d6f2eb 100644
--- a/Modules/TestQuestionPool/test/assBaseTestCase.php
+++ b/Modules/TestQuestionPool/test/assBaseTestCase.php
@@ -2,6 +2,8 @@
 /* Copyright (c) 1998-2018 ILIAS open source, Extended GPL, see docs/LICENSE */
 
 use PHPUnit\Framework\TestCase;
+use ILIAS\Refinery\Factory as RefineryFactory;
+use ILIAS\Refinery\Random\Group as RandomGroup;
 
 /**
  * Class assBaseTestCase
@@ -48,6 +50,10 @@ protected function setUp() : void
         $DIC['rbacsystem'] = $rbacsystem_mock;
         $GLOBALS['rbacsystem'] = $rbacsystem_mock;
 
+        $refineryMock = $this->getMockBuilder(RefineryFactory::class)->disableOriginalConstructor()->getMock();
+        $refineryMock->expects(self::any())->method('random')->willReturn($this->getMockBuilder(RandomGroup::class)->getMock());
+        $DIC['refinery'] = $refineryMock;
+
         parent::setUp();
     }
 
diff --git a/Modules/TestQuestionPool/test/assClozeGapTest.php b/Modules/TestQuestionPool/test/assClozeGapTest.php
index 2ed904b33c1d..55eb372e742a 100644
--- a/Modules/TestQuestionPool/test/assClozeGapTest.php
+++ b/Modules/TestQuestionPool/test/assClozeGapTest.php
@@ -1,6 +1,9 @@
 <?php
 /* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
+use ILIAS\Refinery\Transformation;
+use ILIAS\Refinery\Effect\Effect;
+
 /**
 * Unit tests
 *
@@ -25,7 +28,6 @@ protected function setUp() : void
         parent::setUp();
 
         require_once './Services/Utilities/classes/class.ilUtil.php';
-        require_once './Services/Randomization/classes/class.ilArrayElementShuffler.php';
         $util_mock = $this->createMock('ilUtil', array('stripSlashes'), array(), '', false);
         $util_mock->expects($this->any())->method('stripSlashes')->will($this->returnArgument(0));
         $this->setGlobalVariable('ilUtils', $util_mock);
@@ -99,11 +101,16 @@ public function test_arrayShuffle_shouldNotReturnArrayUnshuffled()
             'Meyer', 'Jansen', 'Heyser', 'Becker');
         $instance->items = $the_unexpected;
         $instance->setShuffle(true);
-        
-        $actual = $instance->getItems(new ilArrayElementShuffler);
+        $theExpected = ['hua', 'haaa', 'some random values'];
+
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+        $mockEffect->expects(self::once())->method('value')->willReturn($theExpected);
+        $transformationMock->expects(self::once())->method('transform')->with($the_unexpected)->willReturn($mockEffect);
+        $actual = $instance->getItems($transformationMock);
 
         // Assert
-        $this->assertNotEquals($the_unexpected, $actual);
+        $this->assertEquals($theExpected, $actual);
     }
     
     public function test_addGetItem_shouldReturnValueUnchanged()
@@ -201,7 +208,9 @@ public function test_getItems_shouldReturnItemsAdded()
         $instance->addItem($item2);
         $instance->addItem($item3);
         $instance->addItem($item4);
-        $actual = $instance->getItems(new ilArrayElementShuffler);
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $transformationMock->expects(self::never())->method('transform');
+        $actual = $instance->getItems($transformationMock);
 
         // Assert
         $this->assertEquals($expected, $actual);
@@ -214,38 +223,33 @@ public function test_getItemsWithShuffle_shouldReturnItemsAddedShuffled()
         $instance = new assClozeGap(0); // 0 - text gap
         $instance->setShuffle(true);
         require_once './Modules/TestQuestionPool/classes/class.assAnswerCloze.php';
-        $item1 = new assAnswerCloze('Bert', 1.0, 0);
-        $item2 = new assAnswerCloze('Fred', 1.0, 1);
-        $item3 = new assAnswerCloze('Karl', 1.0, 2);
-        $item4 = new assAnswerCloze('Esther', 1.0, 3);
-        $item5 = new assAnswerCloze('Herbert', 1.0, 4);
-        $item6 = new assAnswerCloze('Karina', 1.0, 5);
-        $item7 = new assAnswerCloze('Helmut', 1.0, 6);
-        $item8 = new assAnswerCloze('Kerstin', 1.0, 7);
-        $expected = array($item1, $item2, $item3, $item4, $item5, $item6, $item7, $item8);
+        $expected = [
+            new assAnswerCloze('Bert', 1.0, 0),
+            new assAnswerCloze('Fred', 1.0, 1),
+            new assAnswerCloze('Karl', 1.0, 2),
+            new assAnswerCloze('Esther', 1.0, 3),
+            new assAnswerCloze('Herbert', 1.0, 4),
+            new assAnswerCloze('Karina', 1.0, 5),
+            new assAnswerCloze('Helmut', 1.0, 6),
+            new assAnswerCloze('Kerstin', 1.0, 7),
+        ];
+
+        $shuffledArray = ['some shuffled array', 'these values dont matter'];
 
         // Act
-        $instance->addItem($item1);
-        $instance->addItem($item2);
-        $instance->addItem($item3);
-        $instance->addItem($item4);
-        $instance->addItem($item5);
-        $instance->addItem($item6);
-        $instance->addItem($item7);
-        $instance->addItem($item8);
-        $actual = $instance->getItems(new ilArrayElementShuffler);
+        foreach ($expected as $item) {
+            $instance->addItem($item);
+        }
+
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+        $mockEffect->expects(self::once())->method('value')->willReturn($shuffledArray);
+        $transformationMock->expects(self::once())->method('transform')->with($expected)->willReturn($mockEffect);
+        $actual = $instance->getItems($transformationMock);
 
         // Assert
-        $this->assertTrue(is_array($actual));
-        $this->assertTrue(in_array($item1, $actual));
-        $this->assertTrue(in_array($item2, $actual));
-        $this->assertTrue(in_array($item3, $actual));
-        $this->assertTrue(in_array($item4, $actual));
-        $this->assertTrue(in_array($item5, $actual));
-        $this->assertTrue(in_array($item6, $actual));
-        $this->assertTrue(in_array($item7, $actual));
-        $this->assertTrue(in_array($item8, $actual));
-        $this->assertNotEquals($expected, $actual);
+
+        $this->assertEquals($shuffledArray, $actual);
     }
 
     public function test_getItemsRaw_shouldReturnItemsAdded()
@@ -527,7 +531,7 @@ public function test_getBestSolutionOutput_shouldReturnBestSolutionOutput_CaseTe
         $expected = 'Esther';
 
         // Act
-        $actual = $instance->getBestSolutionOutput(new ilArrayElementShuffler);
+        $actual = $instance->getBestSolutionOutput($this->getDummyTransformationMock());
 
         // Assert
         $this->assertEquals($expected, $actual);
@@ -563,7 +567,7 @@ public function test_getBestSolutionOutput_shouldReturnBestSolutionOutput_CaseTe
         $expected2 = 'Esther or Karl';
 
         // Act
-        $actual = $instance->getBestSolutionOutput(new ilArrayElementShuffler);
+        $actual = $instance->getBestSolutionOutput($this->getDummyTransformationMock());
 
         // Assert
         $this->assertTrue(($actual == $expected1) || ($actual == $expected2));
@@ -597,7 +601,7 @@ public function test_getBestSolutionOutput_shouldReturnBestSolutionOutput_CaseNu
         $expected = 100;
 
         // Act
-        $actual = $instance->getBestSolutionOutput(new ilArrayElementShuffler);
+        $actual = $instance->getBestSolutionOutput($this->getDummyTransformationMock());
 
         // Assert
         $this->assertEquals($expected, $actual);
@@ -631,9 +635,24 @@ public function test_getBestSolutionOutput_shouldReturnEmptyStringOnUnknownType_
         $expected = '';
 
         // Act
-        $actual = $instance->getBestSolutionOutput(new ilArrayElementShuffler);
+        $actual = $instance->getBestSolutionOutput($this->getDummyTransformationMock());
 
         // Assert
         $this->assertEquals($expected, $actual);
     }
+
+    private function getDummyTransformationMock() : Transformation
+    {
+
+        $callback = function (array $array) : Effect {
+            $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+            $mockEffect->expects(self::once())->method('value')->willReturn($array);
+
+            return $mockEffect;
+        };
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $transformationMock->expects(self::any())->method('transform')->willReturnCallback($callback);
+
+        return $transformationMock;
+    }
 }
diff --git a/Modules/TestQuestionPool/test/assClozeSelectGapTest.php b/Modules/TestQuestionPool/test/assClozeSelectGapTest.php
index 71e7ba588890..142f2f63a702 100644
--- a/Modules/TestQuestionPool/test/assClozeSelectGapTest.php
+++ b/Modules/TestQuestionPool/test/assClozeSelectGapTest.php
@@ -3,6 +3,9 @@
 
 require_once __DIR__ . "/assBaseTestCase.php";
 
+use ILIAS\Refinery\Transformation;
+use ILIAS\Refinery\Effect\Effect;
+
 /**
 * Unit tests
 *
@@ -54,10 +57,14 @@ public function test_arrayShuffle_shouldShuffleArray()
         // Arrange
         require_once './Modules/TestQuestionPool/classes/class.assClozeSelectGap.php';
         $instance = new assClozeSelectGap(1); // 1 - select gap
-        $expected = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
+        $expected = ['shfksdfs', 'sfsdf', 'sdfsdfdf'];
 
-        $actual = $instance->getItems(new ilArrayElementShuffler());
-        $this->assertNotEquals($expected, $actual);
+        $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+        $mockEffect->expects(self::once())->method('value')->willReturn($expected);
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $transformationMock->expects(self::once())->method('transform')->willReturn($mockEffect);
+        $actual = $instance->getItems($transformationMock);
+        $this->assertEquals($expected, $actual);
     }
 
     public function test_getItemswithShuffle_shouldReturnShuffledItems()
@@ -89,11 +96,13 @@ public function test_getItemswithShuffle_shouldReturnShuffledItems()
         $sequence = [$item1, $item3, $item2, $item4, $item5, $item6, $item7, $item8];
         $expectedSequence = array_reverse($sequence);
 
-        $randomElmProvider = $this->getMockBuilder(ilRandomArrayElementProvider::class)->getMock();
+        $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+        $mockEffect->expects(self::once())->method('value')->willReturn($expectedSequence);
+        $randomElmProvider = $this->getMockBuilder(Transformation::class)->getMock();
         $randomElmProvider->expects($this->once())
-                          ->method('shuffle')
+                          ->method('transform')
                           ->with($sequence)
-                          ->willReturn($expectedSequence);
+                          ->willReturn($mockEffect);
 
         $actual = $instance->getItems($randomElmProvider);
         $this->assertEquals($actual, $expectedSequence);
@@ -118,7 +127,14 @@ public function test_getItemswithoutShuffle_shouldReturnItemsInOrder()
         $instance->setType(false);
 
         $expected = array($item1, $item2, $item3, $item4);
-        $actual = $instance->getItems(new ilDeterministicArrayElementProvider());
+        $transformationMock = $this->getMockBuilder(Transformation::class)->getMock();
+        $transformationMock->expects(self::once())->method('transform')->willReturnCallback(function ($value) {
+            $mockEffect = $this->getMockBuilder(Effect::class)->getMock();
+            $mockEffect->expects(self::once())->method('value')->willReturn($value);
+
+            return $mockEffect;
+        });
+        $actual = $instance->getItems($transformationMock);
 
         $this->assertEquals($expected, $actual);
     }
diff --git a/Services/Randomization/classes/class.ilArrayElementShuffler.php b/Services/Randomization/classes/class.ilArrayElementShuffler.php
deleted file mode 100644
index 83b45f9ecbfc..000000000000
--- a/Services/Randomization/classes/class.ilArrayElementShuffler.php
+++ /dev/null
@@ -1,64 +0,0 @@
-<?php declare(strict_types=1);
-/* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
-
-/**
- * @author Björn Heyser <bheyser@databay.de>
- * @author Michael Jansen <mjansen@databay.de>
- * @package Services/Randomization
- */
-class ilArrayElementShuffler extends ilBaseRandomElementProvider implements ilRandomArrayElementProvider
-{
-    private function isMtRandomizerAvailable() : bool
-    {
-        return function_exists('mt_srand') && function_exists('mt_rand');
-    }
-
-    protected function getInitialSeed() : int
-    {
-        [$usec, $sec] = explode(' ', microtime());
-
-        return (int) ($sec + ($usec * 100000));
-    }
-
-    private function initSeed(int $seed) : void
-    {
-        if ($this->isMtRandomizerAvailable()) {
-            mt_srand($seed);
-        } else {
-            srand($seed);
-        }
-    }
-
-    private function shuffleArray(array $array) : array
-    {
-        if ($this->isMtRandomizerAvailable()) {
-            return $this->mtShuffle($array);
-        }
-
-        shuffle($array);
-
-        return $array;
-    }
-
-    private function mtShuffle(array $orderedArray) : array
-    {
-        $shuffledArray = [];
-
-        while (count($orderedArray) > 0) {
-            $key = mt_rand(0, (count($orderedArray) - 1));
-            $splice = array_splice($orderedArray, $key, 1);
-            $shuffledArray[] = current($splice);
-        }
-
-        return $shuffledArray;
-    }
-
-    public function shuffle(array $array) : array
-    {
-        $this->initSeed($this->getSeed());
-        $array = $this->shuffleArray($array);
-        $this->initSeed($this->getInitialSeed());
-
-        return $array;
-    }
-}
diff --git a/Services/Randomization/classes/class.ilBaseRandomElementProvider.php b/Services/Randomization/classes/class.ilBaseRandomElementProvider.php
deleted file mode 100644
index 310ee1fecbb9..000000000000
--- a/Services/Randomization/classes/class.ilBaseRandomElementProvider.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php declare(strict_types=1);
-
-/**
- * Class ilBaseRandomElementProvider
- * @author Michael Jansen <mjansen@databay.de>
- */
-abstract class ilBaseRandomElementProvider implements ilRandomArrayElementProvider
-{
-    protected int $seed;
-
-    public function __construct()
-    {
-        $this->setSeed($this->getInitialSeed());
-    }
-
-    abstract protected function getInitialSeed() : int;
-
-    public function getSeed() : int
-    {
-        return $this->seed;
-    }
-
-    public function setSeed(int $seed) : void
-    {
-        $this->seed = $seed;
-    }
-
-    public function buildSeedFromString(string $string) : int
-    {
-        return (int) hexdec(substr(md5($string), 0, 10));
-    }
-}
diff --git a/Services/Randomization/classes/class.ilDeterministicArrayElementProvider.php b/Services/Randomization/classes/class.ilDeterministicArrayElementProvider.php
deleted file mode 100644
index 35b560a7f86c..000000000000
--- a/Services/Randomization/classes/class.ilDeterministicArrayElementProvider.php
+++ /dev/null
@@ -1,22 +0,0 @@
-<?php
-/* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
-
-require_once 'Services/Randomization/classes/class.ilArrayElementShuffler.php';
-
-/**
- * @author Björn Heyser <bheyser@databay.de>
- * @author Michael Jansen <mjansen@databay.de>
- * @package Services/Randomization
- */
-class ilDeterministicArrayElementProvider extends ilBaseRandomElementProvider implements ilRandomArrayElementProvider
-{
-    protected function getInitialSeed() : int
-    {
-        return 1;
-    }
-
-    public function shuffle(array $array) : array
-    {
-        return $array;
-    }
-}
diff --git a/Services/Randomization/interfaces/interface.ilRandomArrayElementProvider.php b/Services/Randomization/interfaces/interface.ilRandomArrayElementProvider.php
deleted file mode 100644
index d00da1346c9a..000000000000
--- a/Services/Randomization/interfaces/interface.ilRandomArrayElementProvider.php
+++ /dev/null
@@ -1,19 +0,0 @@
-<?php declare(strict_types=1);
-/* Copyright (c) 1998-2021 ILIAS open source, Extended GPL, see docs/LICENSE */
-
-/**
- * Interface ilRandomArrayElementProvider
- * @package Services/Randomization
- * @author Michael Jansen <mjansen@databay.de>
- * @author Marvin Beym <mBeym@databay.de>
- */
-interface ilRandomArrayElementProvider
-{
-    public function getSeed() : int;
-
-    public function setSeed(int $seed) : void;
-
-    public function buildSeedFromString(string $string) : int;
-
-    public function shuffle(array $array) : array;
-}
diff --git a/Services/Randomization/test/RandomizationStrategiesTest.php b/Services/Randomization/test/RandomizationStrategiesTest.php
deleted file mode 100644
index 525640c4417b..000000000000
--- a/Services/Randomization/test/RandomizationStrategiesTest.php
+++ /dev/null
@@ -1,71 +0,0 @@
-<?php declare(strict_types=1);
-
-/* Copyright (c) 1998-2021 ILIAS open source, Extended GPL, see docs/LICENSE */
-
-use PHPUnit\Framework\TestCase;
-
-/**
- * Class RandomizationStrategiesTest
- * @author Michael Jansen <mjansen@databay.de>
- */
-class RandomizationStrategiesTest extends TestCase
-{
-    private const NUM_RUNS = 1000;
-    private const NUM_RANDOM_NUMBERS = 1000;
-    private const NUM_FINAL_ELEMENTS = 10;
-
-    private function randomArrayElementsProvider() : Generator
-    {
-        $randomNumbers = range(0, self::NUM_RANDOM_NUMBERS);
-
-        for ($i = 1; $i <= self::NUM_RUNS; $i++) {
-            $numbersOfRun = $randomNumbers;
-            shuffle($numbersOfRun);
-            $numbersOfRun = array_slice($numbersOfRun, 0, self::NUM_FINAL_ELEMENTS);
-            yield 'Random numbers run ' . $i => $numbersOfRun;
-        }
-    }
-
-    public function testDeterministicElementStrategy() : void
-    {
-        $provider = new ilDeterministicArrayElementProvider();
-
-        foreach ($this->randomArrayElementsProvider() as $runInfo => $elements) {
-            $provider->setSeed(1);
-            $actualWithInitialSeed = $provider->shuffle($elements);
-            if ($elements !== $actualWithInitialSeed) {
-                $this->fail($runInfo . ' unexpectedly resulted in a random order of elements.');
-            }
-
-            $provider->setSeed(2);
-            $actualWithOtherSeed = $provider->shuffle($elements);
-            if ($elements !== $actualWithOtherSeed) {
-                $this->fail($runInfo . ' unexpectedly resulted in a random order of elements.');
-            }
-        }
-
-        $this->assertTrue(true, 'Shuffling elements with ' . get_class($provider) . ' resulted in output=input');
-    }
-
-    /**
-     * Attention: Testing random is generally a bad idea, but we assume that from the defined N runs at least 1
-     * one will randomly return a random ordering of elements
-     */
-    public function testRandomElementStrategy() : void
-    {
-        foreach ($this->randomArrayElementsProvider() as $runInfo => $elements) {
-            $provider = new ilArrayElementShuffler();
-            $actual = $provider->shuffle($elements);
-
-            if ($elements !== $actual) {
-                $this->assertTrue(true, $runInfo . ' resulted in a random ordering of elements');
-                return;
-            }
-        }
-
-        $this->fail(sprintf(
-            'None of %s runs resulted in a random ordering of elements',
-            self::NUM_RUNS
-        ));
-    }
-}
diff --git a/src/Refinery/Effect/Effect.php b/src/Refinery/Effect/Effect.php
new file mode 100644
index 000000000000..36517421cb6a
--- /dev/null
+++ b/src/Refinery/Effect/Effect.php
@@ -0,0 +1,19 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Effect;
+
+/**
+ * This interface represents a semantic measure to indicate an intentional side effect.
+ * This interface can be used as a return value from Transformation::transform(...) to keep a neccessary side effect out of the transformation itself.
+ * The interface is NOT required to have a side effect.
+ */
+interface Effect
+{
+    /**
+     * @return mixed // can return everything
+     */
+    public function value();
+}
diff --git a/src/Refinery/Effect/IdentityEffect.php b/src/Refinery/Effect/IdentityEffect.php
new file mode 100644
index 000000000000..9c5629ad21c7
--- /dev/null
+++ b/src/Refinery/Effect/IdentityEffect.php
@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+namespace ILIAS\Refinery\Effect;
+
+class IdentityEffect implements Effect
+{
+    private $value;
+
+    public function __construct($value)
+    {
+        $this->value = $value;
+    }
+
+    public function value()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Refinery/Effect/Transformation/LiftTransformation.php b/src/Refinery/Effect/Transformation/LiftTransformation.php
new file mode 100644
index 000000000000..304e85be2464
--- /dev/null
+++ b/src/Refinery/Effect/Transformation/LiftTransformation.php
@@ -0,0 +1,60 @@
+<?php declare(strict_types=1);
+
+namespace ILIAS\Refinery\Effect\Transformation;
+
+use ILIAS\Refinery\Transformation;
+use ILIAS\Refinery\Effect\IdentityEffect;
+use ILIAS\Data\Result;
+use ILIAS\Data\Result\Ok;
+use ILIAS\Refinery\Effect\Effect;
+
+class LiftTransformation implements Transformation
+{
+    /**
+     * Same as transform but returns a Result instead of an exception.
+     *
+     * @return Result<Effect>
+     */
+    public function transformResult($from) : Result
+    {
+        return $this->validate($from)->map([$this, 'createEffect']);
+    }
+
+    /**
+     * @throws \InvalidArgumentException
+     * @return Effect
+     */
+    public function transform($from)
+    {
+        return $this->transformResult($from)->value();
+    }
+
+    /**
+     * @return Result<Effect>
+     */
+    public function applyTo(Result $result) : Result
+    {
+        return $result->then([$this, 'transformResult']);
+    }
+
+    /**
+     * @return Result<Effect>
+     */
+    public function __invoke($from)
+    {
+        return $this->transform($from);
+    }
+
+    /**
+     * @return Result<Effect>
+     */
+    protected function validate($from) : Result
+    {
+        return new Ok($from);
+    }
+
+    public function createEffect($value) : Effect
+    {
+        return new IdentityEffect($value);
+    }
+}
diff --git a/src/Refinery/Factory.php b/src/Refinery/Factory.php
index 4e6c57181294..f990e3cb07bc 100644
--- a/src/Refinery/Factory.php
+++ b/src/Refinery/Factory.php
@@ -7,6 +7,7 @@
 use ILIAS\Refinery\In;
 use ILIAS\Refinery\To;
 use ILIAS\Refinery\ByTrying;
+use ILIAS\Refinery\Random\Group as RandomGroup;
 
 /**
  * @author  Niels Theen <ntheen@databay.de>
@@ -146,4 +147,9 @@ public function byTrying(array $transformations) : ByTrying
     {
         return new ByTrying($transformations, $this->dataFactory, $this->language);
     }
+
+    public function random() : RandomGroup
+    {
+        return new RandomGroup();
+    }
 }
diff --git a/src/Refinery/Random/Effect/ShuffleEffect.php b/src/Refinery/Random/Effect/ShuffleEffect.php
new file mode 100644
index 000000000000..8e716150f548
--- /dev/null
+++ b/src/Refinery/Random/Effect/ShuffleEffect.php
@@ -0,0 +1,29 @@
+<?php declare(strict_types=1);
+
+namespace ILIAS\Refinery\Random\Effect;
+
+use ILIAS\Refinery\Effect\IdentityEffect;
+use ILIAS\Refinery\Random\Seed\Seed;
+
+class ShuffleEffect extends IdentityEffect
+{
+    private Seed $seed;
+
+    public function __construct(array $value, Seed $seed)
+    {
+        parent::__construct($value);
+        $this->seed = $seed;
+    }
+
+    /**
+     * @return array
+     */
+    public function value()
+    {
+        $this->seed->seedRandomGenerator();
+        $value = parent::value();
+        \shuffle($value);
+
+        return $value;
+    }
+}
diff --git a/src/Refinery/Random/Group.php b/src/Refinery/Random/Group.php
new file mode 100644
index 000000000000..66844214e1fd
--- /dev/null
+++ b/src/Refinery/Random/Group.php
@@ -0,0 +1,34 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Random;
+
+use ILIAS\Refinery\Transformation;
+use ILIAS\Refinery\Random\Transformation\ShuffleTransformation;
+use ILIAS\Refinery\Random\Seed\Seed;
+use ILIAS\Refinery\Effect\Transformation\LiftTransformation;
+
+class Group
+{
+    /**
+     * Get a transformation which will shuffle a given array.
+     * Only arrays can be supplied to the transformation.
+     *
+     * The transformation will be shuffled with the given $seed.
+     */
+    public function shuffleArray(Seed $seed) : Transformation
+    {
+        return new ShuffleTransformation($seed);
+    }
+
+    /**
+     * Get a transformation which will return the given value as is.
+     * Everything can be supplied to the transformation.
+     */
+    public function dontShuffle() : Transformation
+    {
+        return new LiftTransformation();
+    }
+}
diff --git a/src/Refinery/Random/Seed/GivenSeed.php b/src/Refinery/Random/Seed/GivenSeed.php
new file mode 100644
index 000000000000..c2f8f5530067
--- /dev/null
+++ b/src/Refinery/Random/Seed/GivenSeed.php
@@ -0,0 +1,26 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Random\Seed;
+
+class GivenSeed implements Seed
+{
+    private int $seed;
+
+    public function __construct(int $seed)
+    {
+        $this->seed = $seed;
+    }
+
+    public function seedRandomGenerator() : void
+    {
+        mt_srand($this->seed);
+    }
+
+    public function getSeed() : int
+    {
+        return $this->seed();
+    }
+}
diff --git a/src/Refinery/Random/Seed/RandomSeed.php b/src/Refinery/Random/Seed/RandomSeed.php
new file mode 100644
index 000000000000..d45a81dbdeca
--- /dev/null
+++ b/src/Refinery/Random/Seed/RandomSeed.php
@@ -0,0 +1,22 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Random\Seed;
+
+class RandomSeed extends GivenSeed
+{
+    public function __construct()
+    {
+        parent::__construct($this->createSeed());
+    }
+
+    public function createSeed() : int
+    {
+        $array = explode(' ', microtime());
+        $seed = $array[1] + ($array[0] * 100000);
+
+        return $seed;
+    }
+}
diff --git a/src/Refinery/Random/Seed/Seed.php b/src/Refinery/Random/Seed/Seed.php
new file mode 100644
index 000000000000..7dbe51d12ffa
--- /dev/null
+++ b/src/Refinery/Random/Seed/Seed.php
@@ -0,0 +1,12 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Random\Seed;
+
+interface Seed
+{
+    public function seedRandomGenerator() : void;
+    public function getSeed() : int;
+}
diff --git a/src/Refinery/Random/Transformation/ShuffleTransformation.php b/src/Refinery/Random/Transformation/ShuffleTransformation.php
new file mode 100644
index 000000000000..8f9449197441
--- /dev/null
+++ b/src/Refinery/Random/Transformation/ShuffleTransformation.php
@@ -0,0 +1,41 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Refinery\Random\Transformation;
+
+use ILIAS\Refinery\Transformation;
+use ILIAS\Data\Result;
+use ILIAS\Data\Result\Ok;
+use ILIAS\Data\Result\Error;
+use ILIAS\Refinery\Random\Seed\Seed;
+use ILIAS\Refinery\Random\Effect\ShuffleEffect;
+use ILIAS\Refinery\Effect\Effect;
+use ILIAS\Refinery\Effect\Transformation\LiftTransformation;
+
+class ShuffleTransformation extends LiftTransformation
+{
+    private Seed $seed;
+
+    public function __construct(Seed $seed)
+    {
+        $this->seed = $seed;
+    }
+
+    /**
+     * @param array $value
+     */
+    public function createEffect($value) : Effect
+    {
+        return new ShuffleEffect($value, $this->seed);
+    }
+
+    /**
+     * @return Result<Effect<array>>
+     */
+    protected function validate($from) : Result
+    {
+        return is_array($from) ? new Ok($from) : new Error('I need an array');
+    }
+}
diff --git a/tests/Refinery/Effect/Transformation/LiftTransformationTest.php b/tests/Refinery/Effect/Transformation/LiftTransformationTest.php
new file mode 100644
index 000000000000..1482cdac4354
--- /dev/null
+++ b/tests/Refinery/Effect/Transformation/LiftTransformationTest.php
@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Tests\Refinery\Effect\Transformation;
+
+use ILIAS\Data\NotOKException;
+use ILIAS\Data\Result\OK;
+use ILIAS\Data\Result\Error;
+use ILIAS\Refinery\Effect\Transformation\LiftTransformation;
+use PHPUnit\Framework\TestCase;
+use ILIAS\Refinery\Effect\Effect;
+
+class LiftTransformationTest extends TestCase
+{
+    public function testTransform() : void
+    {
+        $value = 'hejaaa';
+
+        $actual = (new LiftTransformation())->transform($value);
+
+        $this->assertInstanceOf(Effect::class, $actual);
+        $this->assertEquals($value, $actual->value());
+    }
+
+    public function testInvoke() : void
+    {
+        $value = ['bababa', 'uauauau'];
+
+        $actual = (new LiftTransformation())($value);
+
+        $this->assertInstanceOf(Effect::class, $actual);
+        $this->assertEquals($value, $actual->value());
+    }
+
+    public function testTransformResult() : void
+    {
+        $value = 678;
+
+        $actual = (new LiftTransformation())->transformResult($value);
+
+        $this->assertInstanceOf(OK::class, $actual);
+        $this->assertInstanceOf(Effect::class, $actual->value());
+        $this->assertEquals($value, $actual->value()->value());
+    }
+
+    public function testApplyToOk() : void
+    {
+        $value = ['im in an array'];
+        $result = (new LiftTransformation())->applyTo(new OK($value));
+        $this->assertInstanceOf(OK::class, $result);
+        $this->assertInstanceOf(Effect::class, $result->value());
+        $this->assertEquals($value, $result->value()->value());
+    }
+
+    public function testApplyToError() : void
+    {
+        $error = new Error('some error');
+        $result = (new LiftTransformation())->applyTo($error);
+        $this->assertEquals($error, $result);
+    }
+}
diff --git a/tests/Refinery/FactoryTest.php b/tests/Refinery/FactoryTest.php
index 8fe26ae6487c..bb9187d91090 100644
--- a/tests/Refinery/FactoryTest.php
+++ b/tests/Refinery/FactoryTest.php
@@ -97,7 +97,7 @@ public function testCreateDateTimeGroup()
         $this->assertInstanceOf(\ILIAS\Refinery\DateTime\Group::class, $group);
     }
 
-    public function testCreateUriGrouo()
+    public function testCreateUriGroup()
     {
         $group = $this->basicFactory->uri();
         $this->assertInstanceOf(\ILIAS\Refinery\URI\Group::class, $group);
@@ -111,4 +111,10 @@ public function testByTryingInGroup()
         ]);
         $this->assertInstanceOf(\ILIAS\Refinery\ByTrying::class, $instance);
     }
+
+    public function testRandomGroup()
+    {
+        $instance = $this->basicFactory->random();
+        $this->assertInstanceOf(\ILIAS\Refinery\Random\Group::class, $instance);
+    }
 }
diff --git a/tests/Refinery/Random/Effect/ShuffleEffect.php b/tests/Refinery/Random/Effect/ShuffleEffect.php
new file mode 100644
index 000000000000..27ca6ff540d4
--- /dev/null
+++ b/tests/Refinery/Random/Effect/ShuffleEffect.php
@@ -0,0 +1,21 @@
+<?php declare(strict_types=1);
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Tests\Refinery\Random\Effect;
+
+use PHPUnit\Framework\TestCase;
+use ILIAS\Refinery\Random\Seed\Seed;
+
+class ShuffleEffect extends TestCase
+{
+    public function testValue() : void
+    {
+        $value = ['arrr']
+        $seedMock = $this->getMockBuilder(Seed::class)->getMock();
+        $seedMock->expects(self::once())->method('seedRandomGenerator');
+        $result = (new ShuffleEffect($value, $seedMock))->value();
+        $this->assertEquals($value, $result);
+    }
+}
diff --git a/tests/Refinery/Random/GroupTest.php b/tests/Refinery/Random/GroupTest.php
new file mode 100644
index 000000000000..49e956d60f15
--- /dev/null
+++ b/tests/Refinery/Random/GroupTest.php
@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Tests\Refinery\Random;
+
+use ILIAS\Refinery\Random\Group;
+use ILIAS\Refinery\Transformation;
+use PHPUnit\Framework\TestCase;
+use ILIAS\Refinery\Random\Seed\Seed;
+use ILIAS\Refinery\Effect\Transformation\LiftTransformation;
+use ILIAS\Refinery\Random\Transformation\ShuffleTransformation;
+
+class GroupTest extends TestCase
+{
+    /**
+     * @var Group
+     */
+    private $group;
+
+    public function setUp() : void
+    {
+        $this->group = new Group();
+    }
+
+    public function testShuffle() : void
+    {
+        $mock = $this->getMockBuilder(Seed::class)->getMock();
+        $mock->expects(self::never())->method('seedRandomGenerator');
+        $instance = $this->group->shuffleArray($mock);
+        $this->assertInstanceOf(ShuffleTransformation::class, $instance);
+    }
+
+    public function testDontShuffle() : void
+    {
+        $instance = $this->group->dontShuffle();
+        $this->assertInstanceOf(LiftTransformation::class, $instance);
+    }
+}
diff --git a/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php b/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php
new file mode 100644
index 000000000000..3fe8e174c083
--- /dev/null
+++ b/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php
@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * @author  Lukas Scharmer <lscharmer@databay.de>
+ */
+namespace ILIAS\Tests\Refinery\Random\Transformation;
+
+use ILIAS\Refinery\Random\Transformation\ShuffleTransformation;
+use ILIAS\Refinery\Random\Seed\Seed;
+use ILIAS\Refinery\Random\Effect\ShuffleEffect;
+use ILIAS\Data\NotOKException;
+use ILIAS\Data\Result\OK;
+use ILIAS\Data\Result\Error;
+use PHPUnit\Framework\TestCase;
+
+class ShuffleTransformationTest extends TestCase
+{
+    public function testTransformResultSuccess() : void
+    {
+        $value = ['nrrrrg'];
+        $seedMock = $this->getMockBuilder(Seed::class)->getMock();
+        $seedMock->expects(self::never())->method('seedRandomGenerator');
+
+        $result = (new ShuffleTransformation($seedMock))->transformResult($value);
+        $this->assertInstanceOf(OK::class, $result);
+        $this->assertInstanceOf(ShuffleEffect::class, $result->value());
+    }
+
+    public function testTransformResultFailure() : void
+    {
+        $seedMock = $this->getMockBuilder(Seed::class)->getMock();
+        $seedMock->expects(self::never())->method('seedRandomGenerator');
+
+        $result = (new ShuffleTransformation($seedMock))->transformResult('im no array');
+        $this->assertInstanceOf(Error::class, $result);
+    }
+}

From 0f61ceb15c2ae7f6f69532732b2a22fade3d283c Mon Sep 17 00:00:00 2001
From: Lukas Scharmer <lscharmer@databay.de>
Date: Fri, 5 Nov 2021 10:51:51 +0100
Subject: [PATCH 2/2] Adjust Seed and LiftTransformation

---
 .../Transformation/LiftTransformation.php     | 22 ++++++++-------
 src/Refinery/Random/Seed/GivenSeed.php        |  5 ----
 src/Refinery/Random/Seed/Seed.php             |  1 -
 .../Transformation/LiftTransformationTest.php | 27 +++----------------
 .../ShuffleTransformationTest.php             | 11 ++++----
 5 files changed, 20 insertions(+), 46 deletions(-)

diff --git a/src/Refinery/Effect/Transformation/LiftTransformation.php b/src/Refinery/Effect/Transformation/LiftTransformation.php
index 304e85be2464..887964c096e3 100644
--- a/src/Refinery/Effect/Transformation/LiftTransformation.php
+++ b/src/Refinery/Effect/Transformation/LiftTransformation.php
@@ -7,15 +7,23 @@
 use ILIAS\Data\Result;
 use ILIAS\Data\Result\Ok;
 use ILIAS\Refinery\Effect\Effect;
+use ILIAS\Refinery\DeriveInvokeFromTransform;
 
+/**
+ * "Lifts" a value to an Effect (T => Effect<T>).
+ * Creates a parameterized type (in this case Effect<T>) from another type (T).
+ * @see https://wiki.haskell.org/Lifting
+ */
 class LiftTransformation implements Transformation
 {
+    use DeriveInvokeFromTransform;
+
     /**
      * Same as transform but returns a Result instead of an exception.
      *
      * @return Result<Effect>
      */
-    public function transformResult($from) : Result
+    private function transformResult($from) : Result
     {
         return $this->validate($from)->map([$this, 'createEffect']);
     }
@@ -34,15 +42,9 @@ public function transform($from)
      */
     public function applyTo(Result $result) : Result
     {
-        return $result->then([$this, 'transformResult']);
-    }
-
-    /**
-     * @return Result<Effect>
-     */
-    public function __invoke($from)
-    {
-        return $this->transform($from);
+        return $result->then(function ($from) {
+            return $this->transformResult($from);
+        });
     }
 
     /**
diff --git a/src/Refinery/Random/Seed/GivenSeed.php b/src/Refinery/Random/Seed/GivenSeed.php
index c2f8f5530067..b541a6e162de 100644
--- a/src/Refinery/Random/Seed/GivenSeed.php
+++ b/src/Refinery/Random/Seed/GivenSeed.php
@@ -18,9 +18,4 @@ public function seedRandomGenerator() : void
     {
         mt_srand($this->seed);
     }
-
-    public function getSeed() : int
-    {
-        return $this->seed();
-    }
 }
diff --git a/src/Refinery/Random/Seed/Seed.php b/src/Refinery/Random/Seed/Seed.php
index 7dbe51d12ffa..d36c17a23dd6 100644
--- a/src/Refinery/Random/Seed/Seed.php
+++ b/src/Refinery/Random/Seed/Seed.php
@@ -8,5 +8,4 @@
 interface Seed
 {
     public function seedRandomGenerator() : void;
-    public function getSeed() : int;
 }
diff --git a/tests/Refinery/Effect/Transformation/LiftTransformationTest.php b/tests/Refinery/Effect/Transformation/LiftTransformationTest.php
index 1482cdac4354..235c8bcd30b9 100644
--- a/tests/Refinery/Effect/Transformation/LiftTransformationTest.php
+++ b/tests/Refinery/Effect/Transformation/LiftTransformationTest.php
@@ -6,7 +6,7 @@
 namespace ILIAS\Tests\Refinery\Effect\Transformation;
 
 use ILIAS\Data\NotOKException;
-use ILIAS\Data\Result\OK;
+use ILIAS\Data\Result\Ok;
 use ILIAS\Data\Result\Error;
 use ILIAS\Refinery\Effect\Transformation\LiftTransformation;
 use PHPUnit\Framework\TestCase;
@@ -24,32 +24,11 @@ public function testTransform() : void
         $this->assertEquals($value, $actual->value());
     }
 
-    public function testInvoke() : void
-    {
-        $value = ['bababa', 'uauauau'];
-
-        $actual = (new LiftTransformation())($value);
-
-        $this->assertInstanceOf(Effect::class, $actual);
-        $this->assertEquals($value, $actual->value());
-    }
-
-    public function testTransformResult() : void
-    {
-        $value = 678;
-
-        $actual = (new LiftTransformation())->transformResult($value);
-
-        $this->assertInstanceOf(OK::class, $actual);
-        $this->assertInstanceOf(Effect::class, $actual->value());
-        $this->assertEquals($value, $actual->value()->value());
-    }
-
     public function testApplyToOk() : void
     {
         $value = ['im in an array'];
-        $result = (new LiftTransformation())->applyTo(new OK($value));
-        $this->assertInstanceOf(OK::class, $result);
+        $result = (new LiftTransformation())->applyTo(new Ok($value));
+        $this->assertInstanceOf(Ok::class, $result);
         $this->assertInstanceOf(Effect::class, $result->value());
         $this->assertEquals($value, $result->value()->value());
     }
diff --git a/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php b/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php
index 3fe8e174c083..f936cc6b57fd 100644
--- a/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php
+++ b/tests/Refinery/Random/Transformation/ShuffleTransformationTest.php
@@ -9,7 +9,7 @@
 use ILIAS\Refinery\Random\Seed\Seed;
 use ILIAS\Refinery\Random\Effect\ShuffleEffect;
 use ILIAS\Data\NotOKException;
-use ILIAS\Data\Result\OK;
+use ILIAS\Data\Result\Ok;
 use ILIAS\Data\Result\Error;
 use PHPUnit\Framework\TestCase;
 
@@ -21,17 +21,16 @@ public function testTransformResultSuccess() : void
         $seedMock = $this->getMockBuilder(Seed::class)->getMock();
         $seedMock->expects(self::never())->method('seedRandomGenerator');
 
-        $result = (new ShuffleTransformation($seedMock))->transformResult($value);
-        $this->assertInstanceOf(OK::class, $result);
-        $this->assertInstanceOf(ShuffleEffect::class, $result->value());
+        $result = (new ShuffleTransformation($seedMock))->transform($value);
+        $this->assertInstanceOf(ShuffleEffect::class, $result);
     }
 
     public function testTransformResultFailure() : void
     {
+        $this->expectException(NotOKException::class);
         $seedMock = $this->getMockBuilder(Seed::class)->getMock();
         $seedMock->expects(self::never())->method('seedRandomGenerator');
 
-        $result = (new ShuffleTransformation($seedMock))->transformResult('im no array');
-        $this->assertInstanceOf(Error::class, $result);
+        $result = (new ShuffleTransformation($seedMock))->transform('im no array');
     }
 }