Fixed return type error in the Doctrine custom types

Author: benatespina

CHANGELOG.md

@@ -5,6 +5,8 @@ This changelog references the relevant changes done between versions.
 To get the diff for a specific change, go to https://github.com/LIN3S/SharedKernel/commit/XXX where XXX is the change hash 
 To get the diff between two versions, go to https://github.com/LIN3S/SharedKernel/compare/v0.7.0...v0.8.0
 
+* 0.9.3
+    * Fixed return type error in the Doctrine custom types. 
 * 0.9.2
     * Added comment support for Doctrine's custom types.
 * 0.9.1

src/LIN3S/SharedKernel/Infrastructure/Persistence/Doctrine/DBAL/Domain/Model/Iban/Types/IbanType.php

@@ -34,7 +34,7 @@ public function convertToDatabaseValue($value, AbstractPlatform $platform) : ?st
     public function convertToPHPValue($value, AbstractPlatform $platform) : ?Iban
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         return Iban::from($value);

src/LIN3S/SharedKernel/Infrastructure/Persistence/Doctrine/DBAL/Domain/Model/Phone/Types/PhoneType.php

@@ -34,7 +34,7 @@ public function convertToDatabaseValue($value, AbstractPlatform $platform) : ?st
     public function convertToPHPValue($value, AbstractPlatform $platform) : ?Phone
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         return Phone::fromInternatinal($value);

src/LIN3S/SharedKernel/Infrastructure/Persistence/Doctrine/DBAL/Domain/Model/TaxIdNumber/Types/TaxIdNumberType.php

@@ -34,7 +34,7 @@ public function convertToDatabaseValue($value, AbstractPlatform $platform) : ?st
     public function convertToPHPValue($value, AbstractPlatform $platform) : ?TaxIdNumber
     {
         if (null === $value) {
-            return;
+            return null;
         }
 
         return TaxIdNumber::fromSpain($value);