fix: EnumCaseToPascalCaseRector skips existing pascal case

Author: calebdw

rules-tests/CodingStyle/Rector/Enum_/EnumCaseToPascalCaseRector/Fixture/skip_existing_pascal.php.inc

@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\CodingStyle\Rector\Enum_\EnumCaseToPascalCaseRector\Fixture;
+
+enum SkipExistingPascal
+{
+    case Pending;
+    case Published;
+    case InReview;
+    case WaitingForApproval;
+}

rules/CodingStyle/Rector/Enum_/EnumCaseToPascalCaseRector.php

@@ -187,7 +187,28 @@ private function refactorClassConstFetch(ClassConstFetch $classConstFetch): ?Nod
 
     private function convertToPascalCase(string $name): string
     {
+        if ($this->isPascalCase($name)) {
+            return $name;
+        }
+
         $parts = explode('_', strtolower($name));
         return implode('', array_map(ucfirst(...), $parts));
     }
+
+    private function isPascalCase(string $name): bool
+    {
+        if (! ctype_upper($name[0])) {
+            return false;
+        }
+
+        if (str_contains($name, '_')) {
+            return false;
+        }
+
+        if (strtoupper($name) === $name) {
+            return false;
+        }
+
+        return true;
+    }
 }