custom validation to allow both lower and upper case file extension

To allow both lower and upper case file extensions and MIME types during file upload in Laravel, you can create a custom validation rule. Here's a step-by-step solution:

1. Create a Custom Validation Rule:

   First, generate a custom validation rule using the Artisan command:

   php artisan make:rule FileExtension
   

2. Implement the Custom Validation Logic:

   Open the generated FileExtension rule class located in app/Rules/FileExtension.php and implement the logic to check for both lower and upper case file extensions and MIME types.

   <?php
   
   namespace App\Rules;
   
   use Illuminate\Contracts\Validation\Rule;
   
   class FileExtension implements Rule
   {
       protected $allowedExtensions;
   
       public function __construct(array $allowedExtensions)
       {
           $this->allowedExtensions = $allowedExtensions;
       }
   
       public function passes($attribute, $value)
       {
           $extension = strtolower($value->getClientOriginalExtension());
           return in_array($extension, array_map('strtolower', $this->allowedExtensions));
       }
   
       public function message()
       {
           return 'The :attribute must be a file of type: ' . implode(', ', $this->allowedExtensions) . '.';
       }
   }
   

3. Use the Custom Validation Rule in Your Controller:

   In your controller, use the custom validation rule when validating the file upload.

   use App\Rules\FileExtension;
   use Illuminate\Http\Request;
   
   class FileUploadController extends Controller
   {
       public function upload(Request $request)
       {
           $request->validate([
               'file' => ['required', 'file', new FileExtension(['jpg', 'jpeg', 'png', 'pdf'])],
           ]);
   
           // Handle the file upload
           $file = $request->file('file');
           $path = $file->store('uploads');
   
           return response()->json(['path' => $path], 200);
       }
   }
   

4. Update Your Routes:

   Ensure you have a route that points to your file upload controller method.

   use App\Http\Controllers\FileUploadController;
   
   Route::post('/upload', [FileUploadController::class, 'upload']);
   

This solution ensures that the file extension is validated in a case-insensitive manner, allowing both lower and upper case file extensions. The custom validation rule checks the file extension against a list of allowed extensions, converting both the file extension and the allowed extensions to lowercase for comparison.