Fixed calculating column chunk statistics for empty array values

src/lib/parquet/src/Flow/Parquet/ParquetFile/RowGroupBuilder/ColumnChunkStatistics.php

@@ -46,7 +46,8 @@ public function add(string|int|float|array|bool|object|null $value) : void
         }
 
         if (\is_array($value)) {
-            $this->valuesCount += \count($value);
+            $arrayValuesCount = \count($value);
+            $this->valuesCount += $arrayValuesCount ?: 1;
         } else {
             $this->valuesCount++;
         }

src/lib/parquet/tests/Flow/Parquet/Tests/Integration/ParquetFile/RowGroupBuilder/ColumnChunkStatisticsTest.php

@@ -5,7 +5,7 @@
 namespace Flow\Parquet\Tests\Integration\ParquetFile\RowGroupBuilder;
 
 use Flow\Parquet\ParquetFile\RowGroupBuilder\ColumnChunkStatistics;
-use Flow\Parquet\ParquetFile\Schema\FlatColumn;
+use Flow\Parquet\ParquetFile\Schema\{FlatColumn, ListElement, NestedColumn};
 use PHPUnit\Framework\TestCase;
 
 final class ColumnChunkStatisticsTest extends TestCase
@@ -181,6 +181,23 @@ public function test_statistics_for_json() : void
         self::assertSame(1, $statistics->nullCount());
     }
 
+    public function test_statistics_for_list_of_ints() : void
+    {
+        /** @var FlatColumn $listElement */
+        $listElement = NestedColumn::list('list_of_ints', ListElement::int64())->getListElement();
+
+        $statistics = new ColumnChunkStatistics($listElement);
+
+        $statistics->add([]);
+        $statistics->add([1]);
+        $statistics->add([1, 2]);
+        $statistics->add([1, 2, 3]);
+
+        self::assertSame(1, $statistics->min());
+        self::assertSame(3, $statistics->max());
+        self::assertSame(7, $statistics->valuesCount());
+    }
+
     public function test_statistics_for_string() : void
     {
         $statistics = new ColumnChunkStatistics(FlatColumn::string('string'));