improve formdata event detection

docs/resources/changelog.md

@@ -14,6 +14,7 @@ _During the beta period, these restrictions may be relaxed in the event of a mis
 - Improved RTL styles for `<sl-button-group>` [#783](https://github.com/shoelace-style/shoelace/issues/783)
 - Improved RTL styles for the toast stack [#785](https://github.com/shoelace-style/shoelace/issues/785)
 - Improved typings for translations and localized terms
+- Improved the `FormData` event polyfill to use simpler detection logic
 - Upgraded @shoelace-style/localize to 3.0
 
 ## 2.0.0-beta.75

src/internal/formdata-event-polyfill.ts

@@ -69,26 +69,8 @@ class FormDataPolyfill extends FormData {
   }
 }
 
-function supportsFormDataEvent() {
-  const form = document.createElement('form');
-  let isSupported = false;
-
-  document.body.append(form);
-
-  form.addEventListener('submit', event => {
-    new FormData(event.target as HTMLFormElement);
-    event.preventDefault();
-  });
-
-  form.addEventListener('formdata', () => (isSupported = true));
-  form.dispatchEvent(new Event('submit', { cancelable: true }));
-  form.remove();
-
-  return isSupported;
-}
-
 function polyfillFormData() {
-  if (!window.FormData || supportsFormDataEvent()) {
+  if (!window.FormData || !('FormDataEvent' in window)) {
     return;
   }