Fixed calculation of definition level in Parquet DremelShredder implementation (#1772)

Author: norberttech

src/lib/parquet/src/Flow/Parquet/Dremel/DremelShredder.php

@@ -178,7 +178,7 @@ private function shredList(NestedColumn $column, ?array $listValue, int $definit
             return;
         }
 
-        if (!$listElementColumn->repetition()?->isRequired()) {
+        if (!$column->repetition()?->isRequired()) {
             $definitionLevel++;
         }
 

src/lib/parquet/tests/Flow/Parquet/Tests/Integration/IO/ListsWritingTest.php

@@ -8,7 +8,7 @@
 use Faker\Factory;
 use Flow\Parquet\{Consts, Reader, Writer};
 use Flow\Parquet\ParquetFile\Schema;
-use Flow\Parquet\ParquetFile\Schema\{FlatColumn, ListElement, NestedColumn};
+use Flow\Parquet\ParquetFile\Schema\{FlatColumn, ListElement, NestedColumn, Repetition};
 use PHPUnit\Framework\TestCase;
 
 final class ListsWritingTest extends TestCase
@@ -226,6 +226,40 @@ public function test_writing_nullable_list_of_structures() : void
         );
     }
 
+    public function test_writing_nullable_list_of_structures_with_required_fields() : void
+    {
+        $path = __DIR__ . '/var/test-writer-parquet-test-' . generate_random_string() . '.parquet';
+
+        $writer = new Writer();
+        $schema = Schema::with(
+            NestedColumn::list(
+                'list_of_structs',
+                ListElement::structure(
+                    [
+                        FlatColumn::int32('id', Repetition::REQUIRED),
+                    ],
+                    true
+                ),
+            )
+        );
+
+        $faker = Factory::create();
+        $inputData = \array_merge(...\array_map(static fn (int $i) : array => [
+            [
+                'list_of_structs' => \array_map(static fn ($i) => [
+                    'id' => $faker->numberBetween(0, Consts::PHP_INT32_MAX),
+                ], \range(1, generate_random_int(2, 10))),
+            ],
+        ], \range(1, 10)));
+
+        $writer->write($path, $schema, $inputData);
+
+        self::assertSame(
+            $inputData,
+            \iterator_to_array((new Reader())->read($path)->values())
+        );
+    }
+
     public function test_writing_nullable_lists_of_ints() : void
     {
         $path = __DIR__ . '/var/test-writer-parquet-test-' . generate_random_string() . '.parquet';