Prevent enum FQCN to have double backslashes

src/Validator.php

@@ -195,6 +195,9 @@ public static function classExists(string $className, string $errorMessage = '')
     {
         self::notBlank($className);
 
+        // normalize class name
+        $className = str_replace('\\\\', '\\', $className);
+
         if (!class_exists($className)) {
             $errorMessage = $errorMessage ?: \sprintf('Class "%s" doesn\'t exist; please enter an existing full class name.', $className);
 
@@ -247,7 +250,7 @@ public static function classIsUserInterface($userClassName): string
 
     public static function classIsBackedEnum($backedEnum): string
     {
-        self::classExists($backedEnum);
+        $backedEnum = self::classExists($backedEnum);
 
         if (!isset(class_implements($backedEnum)[\BackedEnum::class])) {
             throw new RuntimeCommandException(\sprintf('The class "%s" is not a valid BackedEnum.', $backedEnum));

tests/Maker/MakeEntityTest.php

@@ -762,6 +762,28 @@ public function getTestDetails(): \Generator
             $this->runEntityTest($runner);
         }),
         ];
+
+        yield 'it_does_not_throw_error_with_double_slashes' => [$this->createMakeEntityTest()
+            ->run(function (MakerTestRunner $runner) {
+                $this->copyEntity($runner, 'Enum/Role-basic.php');
+
+                $runner->runMaker([
+                    // entity class name
+                    'User',
+                    // add additional field
+                    'role',
+                    'enum',
+                    'App\\\\Entity\\\\Enum\\\\Role',
+                    '',
+                    // nullable
+                    'y',
+                    // finish adding fields
+                    '',
+                ]);
+
+                $this->runEntityTest($runner);
+            }),
+        ];
     }
 
     /** @param array<string, mixed> $data */