style: apply code style fixes for consistency and readability

- Updated `ConditionalTransformer`:
- Updated `TemplateTransformer`

Author: walmir-silva

src/Processor/Composite/ConditionalTransformer.php

@@ -10,7 +10,10 @@
 class ConditionalTransformer extends AbstractTransformerProcessor implements ConfigurableProcessor
 {
     private ?AbstractTransformerProcessor $transformer = null;
-    private ?callable $condition = null;
+
+    /** @var callable|null */
+    private mixed $condition = null;
+
     private mixed $defaultValue = null;
     private bool $useDefaultOnError = true;
 
@@ -41,12 +44,14 @@ public function process(mixed $input): mixed
 
             if (!$this->transformer->isValid() && $this->useDefaultOnError) {
                 $this->setInvalid($this->transformer->getErrorKey());
+
                 return $this->defaultValue ?? $input;
             }
 
             return $result;
         } catch (\Exception $e) {
             $this->setInvalid('transformationError');
+
             return $this->defaultValue ?? $input;
         }
     }
@@ -59,4 +64,4 @@ private function shouldTransform(mixed $input): bool
             return false;
         }
     }
-}
+}

src/Processor/String/TemplateTransformer.php

@@ -15,7 +15,10 @@ class TemplateTransformer extends AbstractTransformerProcessor implements Config
     private string $template = '';
     private string $openTag = '{{';
     private string $closeTag = '}}';
-    private ?callable $missingValueHandler = null;
+
+    /** @var callable|null */
+    private mixed $missingValueHandler = null;
+
     private bool $removeUnmatchedTags = false;
 
     public function configure(array $options): void
@@ -31,11 +34,13 @@ public function process(mixed $input): string
     {
         if (!is_array($input)) {
             $this->setInvalid('notArray');
+
             return $this->template;
         }
 
         if (empty($this->template)) {
             $this->setInvalid('noTemplate');
+
             return '';
         }
 
@@ -45,19 +50,19 @@ public function process(mixed $input): string
     private function replacePlaceholders(array $data): string
     {
         $pattern = '/' . preg_quote($this->openTag, '/') . '\s*(.+?)\s*' . preg_quote($this->closeTag, '/') . '/';
-        
-        return preg_replace_callback($pattern, function($matches) use ($data) {
+
+        return preg_replace_callback($pattern, function ($matches) use ($data) {
             $key = trim($matches[1]);
-            
+
             if (isset($data[$key])) {
                 return $data[$key];
             }
-            
-            if ($this->missingValueHandler !== null) {
+
+            if (null !== $this->missingValueHandler) {
                 return call_user_func($this->missingValueHandler, $key);
             }
-            
+
             return $this->removeUnmatchedTags ? '' : $matches[0];
         }, $this->template);
     }
-}
+}