Merge pull request #266 from boesing/qa/shuffle-fisher-yates

Allow random permutations without restrictions

Author: boesing

src/OrderedList.php

@@ -482,10 +482,7 @@ public function shuffle(): OrderedListInterface
 
         $data = $this->data;
 
-        do {
-            shuffle($data);
-        } while ($this->data === $data);
-
+        shuffle($data);
         $instance       = clone $this;
         $instance->data = $data;
 

tests/GenericOrderedListTest.php

@@ -28,6 +28,7 @@
 use function mt_rand;
 use function range;
 use function spl_object_hash;
+use function sprintf;
 use function strlen;
 use function strnatcmp;
 
@@ -1476,16 +1477,31 @@ public function testWillRemoveItemAtSpecificPosition(): void
 
     public function testWillShuffleValuesInList(): void
     {
-        $list = new GenericOrderedList([
-            1,
-            2,
-            3,
-        ]);
+        $values = [1, 2, 3];
+        $list   = new GenericOrderedList($values);
+
+        $maximumShuffleAttempts = 10;
+        $shuffledSameCount      = 0;
+
+        do {
+            $list2 = $list->shuffle();
+            /** @psalm-suppress TypeDoesNotContainType No clue why this is happening but for now we are suppressing */
+            if ($list2->toNativeArray() === $values) {
+                $shuffledSameCount++;
+                self::assertLessThan(
+                    $maximumShuffleAttempts,
+                    $shuffledSameCount,
+                    sprintf('The shuffle did not change the order after "%d" attempts.', $maximumShuffleAttempts),
+                );
+                continue;
+            }
+
+            break;
+        } while ($shuffledSameCount < $maximumShuffleAttempts);
 
-        $list2 = $list->shuffle();
-        self::assertSame([1, 2, 3], $list->toNativeArray());
         self::assertNotSame($list, $list2);
-        self::assertNotSame([1, 2, 3], $list2->toNativeArray());
+        self::assertEqualsCanonicalizing($values, $list2->toNativeArray());
+        self::assertNotSame($values, $list2->toNativeArray());
     }
 
     public function testWillCombineWithAnohterList(): void