Made deprecation reason not nullable.

Author: peldax

composer.lock

@@ -25,6 +25,7 @@ final class DeprecatedDirective extends Directive implements
     EnumItemLocation,
     ArgumentDefinitionLocation
 {
+    public const DEFAULT_MESSAGE = 'No longer supported';
     protected const NAME = 'deprecated';
 
     #[\Override]
@@ -90,7 +91,7 @@ protected function getFieldDefinition() : ArgumentSet
     {
         return new ArgumentSet([
             Argument::create('reason', Container::String()->notNull())
-                ->setDefaultValue('No longer supported'),
+                ->setDefaultValue(self::DEFAULT_MESSAGE),
         ]);
     }
 }

src/Typesystem/Spec/DeprecatedDirective.php

@@ -12,7 +12,7 @@
  */
 trait TDeprecatable
 {
-    public function setDeprecated(?string $reason = null) : self
+    public function setDeprecated(string $reason = DeprecatedDirective::DEFAULT_MESSAGE) : self
     {
         $this->addDirective(
             Container::directiveDeprecated(),
@@ -41,7 +41,7 @@ public function getDeprecationReason() : ?string
 
                 return \is_string($value)
                     ? $value
-                    : null;
+                    : DeprecatedDirective::DEFAULT_MESSAGE;
             }
         }