Support null as an uploadDate in test codec

Author: alcaeus

src/GridFS/WritableStream.php

@@ -137,7 +137,7 @@ public function __construct(CollectionWrapper $collectionWrapper, string $filena
             'chunkSize' => $this->chunkSize,
             'filename' => $filename,
             'length' => 0,
-            'uploadDate' => new UTCDateTime(0),
+            'uploadDate' => null,
         ] + array_intersect_key($options, ['aliases' => 1, 'contentType' => 1, 'metadata' => 1]);
     }
 

tests/Fixtures/Codec/TestFileCodec.php

@@ -31,9 +31,11 @@ public function decode($value): TestFile
         $fileObject->id = $value->get('_id');
         $fileObject->length = (int) $value->get('length');
         $fileObject->chunkSize = (int) $value->get('chunkSize');
-        $fileObject->uploadDate = DateTimeImmutable::createFromMutable($value->get('uploadDate')->toDateTime());
         $fileObject->filename = $value->get('filename');
 
+        $uploadDate = $value->get('uploadDate');
+        $fileObject->uploadDate = $uploadDate ? DateTimeImmutable::createFromMutable($uploadDate->toDateTime()) : null;
+
         if ($value->has('metadata')) {
             $fileObject->metadata = $value->get('metadata');
         }

tests/Fixtures/Document/TestFile.php

@@ -24,7 +24,7 @@ final class TestFile
     public $id;
     public int $length;
     public int $chunkSize;
-    public DateTimeImmutable $uploadDate;
+    public ?DateTimeImmutable $uploadDate = null;
     public string $filename;
     public $metadata;
 }