DX: fix some phpstan issues and add test for ParticipationOverlapValidator.php

src/Bundle/ChillThirdPartyBundle/Form/ChoiceLoader/ThirdPartyChoiceLoader.php

@@ -23,6 +23,8 @@ use function in_array;
 
 /**
  * Lazy load third parties.
+ *
+ * @deprecated As the PickThirdPartyType is deprecated, this should not be in use
  */
 class ThirdPartyChoiceLoader implements ChoiceLoaderInterface
 {
@@ -57,7 +59,7 @@ class ThirdPartyChoiceLoader implements ChoiceLoaderInterface
         $choices = [];
 
         foreach ($values as $value) {
-            if (empty($value)) {
+            if (null === $value || '' === $value) {
                 continue;
             }
 

src/Bundle/ChillThirdPartyBundle/Form/Type/PickThirdPartyType.php

@@ -29,6 +29,10 @@ use function array_merge;
 use function count;
 use function is_array;
 
+/**
+ * @deprecated use the @link{PickThirdPartyDynamicType::class}
+ * @note do remove ThirdPartyChoiceLoader if this class is removed
+ */
 class PickThirdPartyType extends AbstractType
 {
     /**