Fix Stream::sotBy method working with float values

Author: sokolovsky

src/WS/Utils/Collections/SerialStream.php

@@ -137,7 +137,7 @@ public function sortBy(callable $extractor): Stream
         sort($values);
         $newList = $this->emptyList();
         foreach ($values as $value) {
-            $els = $map[$value] ?? [];
+            $els = $map[$value.''] ?? [];
             $newList->addAll($els);
         }
         $this->list = $newList;

tests/WS/Utils/Collections/SerialStreamTest.php

@@ -8,6 +8,7 @@
 use Exception;
 use PHPUnit\Framework\TestCase;
 use WS\Utils\Collections\UnitConstraints\CollectionIsEqual;
+use WS\Utils\Collections\Utils\ExampleObject;
 use WS\Utils\Collections\Utils\InvokeCounter;
 use WS\Utils\Collections\Utils\TestInteger;
 
@@ -502,6 +503,23 @@ public function sortingWithNotScalarValue(): void
         ;
     }
 
+    /**
+     * @test
+     */
+    public function sortingWithSingleValue(): void
+    {
+        $obj = new ExampleObject();
+        $obj->property = 1.12;
+        $sortedFirstElement = $this->createCollection([$obj])
+            ->stream()
+            ->sortBy(static function (ExampleObject $object) {
+                return $object->property;
+            })
+            ->findFirst()
+        ;
+        self::assertNotNull($sortedFirstElement);
+    }
+
     /**
      * @dataProvider sortCases
      * @test