Highligh 'extensions' instead of 'mimeTypes' for File constraint

You should always use the extensions option instead of mimeTypes except if you explicitly don't want to check that the extension of the file is consistent with its content (this can be a security issue). By default, the extensions option also checks the media type of the file.
symfony · xabbuh · May 18, 2025 · Apr 16, 2025 · May 18, 2025 · 3474a09b856214ca239af989d221faa05fe69c4a
commit 3474a09b856214ca239af989d221faa05fe69c4a
diff --git a/controller/upload_file.rst b/controller/upload_file.rst
@@ -77,11 +77,8 @@ so Symfony doesn't try to get/set its value from the related entity::
                    'constraints' => [
                        new File([
                            'maxSize' => '1024k',
-                            'mimeTypes' => [
-                                'application/pdf',
-                                'application/x-pdf',
-                            ],
-                            'mimeTypesMessage' => 'Please upload a valid PDF document',
+                            'extensions' => ['pdf'],
+                            'extensionsMessage' => 'Please upload a valid PDF document',
                        ])
                    ],
                ])