Empty tierprices should remove the form row

src/Form/TierPriceMapper.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Brille24\SyliusTierPricePlugin\Form;
+
+use Symfony\Component\Form\DataMapperInterface;
+use Traversable;
+
+class TierPriceMapper implements DataMapperInterface
+{
+    public function __construct(private DataMapperInterface $inner) {}
+
+    public function mapDataToForms($viewData, Traversable $forms)
+    {
+        $this->inner->mapDataToForms($viewData, $forms);
+    }
+
+    public function mapFormsToData(Traversable $forms, &$viewData)
+    {
+        $formData = iterator_to_array($forms);
+        if ($formData['qty']->getData() === null
+            && $formData['price']->getData() === null
+            && $formData['channel']->getData() === null
+        ) {
+            $viewData = null;
+        } else {
+            $this->inner->mapFormsToData($forms, $viewData);
+        }
+    }
+}

src/Form/TierPriceType.php

@@ -25,6 +25,9 @@
 
 class TierPriceType extends AbstractType
 {
+    public function __construct(private TierPriceMapper $dataMapper) {
+    }
+
     public function buildForm(FormBuilderInterface $builder, array $options): void
     {
         $builder->add('qty', NumberType::class, [
@@ -45,6 +48,8 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
         $builder->add('channel', ChannelChoiceType::class, [
             'attr' => ['style' => 'display:none'],
         ]);
+
+        $builder->setDataMapper($this->dataMapper);
     }
 
     public function configureOptions(OptionsResolver $resolver): void