[11.x] Add tests for handling non-baked enum and empty string requests (#51289)

* Add tests for handling non-baked enum and empty string requests

* use existing request key

---------

Co-authored-by: Hrant Aghanian <haghanian@ronasit.com>

Author: hrant1020

tests/Http/Enums.php

@@ -2,7 +2,13 @@
 
 namespace Illuminate\Tests\Http;
 
-enum TestEnum: string
+enum TestEnumBacked: string
 {
     case test = 'test';
+    case test_empty = '';
+}
+
+enum TestEnum
+{
+    case test;
 }

tests/Http/HttpRequestTest.php

@@ -762,13 +762,16 @@ public function testEnumMethod()
         $request = Request::create('/', 'GET', [
             'valid_enum_value' => 'test',
             'invalid_enum_value' => 'invalid',
+            'empty_value_request' => '',
         ]);
 
-        $this->assertNull($request->enum('doesnt_exists', TestEnum::class));
+        $this->assertNull($request->enum('doesnt_exists', TestEnumBacked::class));
 
-        $this->assertEquals(TestEnum::test, $request->enum('valid_enum_value', TestEnum::class));
+        $this->assertEquals(TestEnumBacked::test, $request->enum('valid_enum_value', TestEnumBacked::class));
 
-        $this->assertNull($request->enum('invalid_enum_value', TestEnum::class));
+        $this->assertNull($request->enum('invalid_enum_value', TestEnumBacked::class));
+        $this->assertNull($request->enum('empty_value_request', TestEnumBacked::class));
+        $this->assertNull($request->enum('valid_enum_value', TestEnum::class));
     }
 
     public function testArrayAccess()