Allow null value in aggregation result

Author: MacFJA

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Bad copy/paste in the [README](README.md) file
+- Allow `null` value in Aggregate result
 
 ## [1.1.0]
 

src/Aggregate/Result.php

@@ -26,24 +26,24 @@
 
 class Result
 {
-    /** @var array<string,float|int|string> */
+    /** @var array<string,null|float|int|string> */
     private $fields = [];
 
     /**
      * Result constructor.
      *
-     * @param array<string,float|int|string> $fields
+     * @param array<string,null|float|int|string> $fields
      *
      * @throws Throwable
      */
     public function __construct(array $fields)
     {
-        DataHelper::assertArrayOf($fields, 'scalar');
+        DataHelper::assertArrayOf($fields, '?scalar');
         $this->fields = $fields;
     }
 
     /**
-     * @return array<string,float|int|string>
+     * @return array<string,null|float|int|string>
      */
     public function getFields(): array
     {

src/Helper/DataHelper.php

@@ -37,6 +37,7 @@
 use function sscanf;
 use function strpos;
 use function strtolower;
+use function substr;
 use Throwable;
 use UnexpectedValueException;
 
@@ -77,12 +78,20 @@ public static function assert(bool $condition, $exception = null, int $deep = 1)
      * @param null|string|Throwable $exception
      *
      * @throws Throwable
-     * @suppress PhanUndeclaredClass
      */
     public static function assertArrayOf(array $array, string $type, $exception = null): void
     {
+        $allowNull = false;
+        if (0 === strpos($type, '?')) {
+            $allowNull = true;
+            $type = substr($type, 1);
+            assert(is_string($type));
+        }
         $type = self::getPhpType($type);
         foreach ($array as $item) {
+            if (true === $allowNull && null === $item) {
+                continue;
+            }
             if (in_array($type, ['string', 'boolean', 'integer', 'double'], true)) {
                 self::assert(gettype($item) === $type, $exception, 2);
             } elseif ('scalar' === $type) {