Add visible check

Author: muan

index.js

@@ -32,7 +32,18 @@ function keydown(event: KeyboardEvent): void {
 }
 
 function focusable(el: Focusable): boolean {
-  return el.tabIndex >= 0 && !el.disabled && !el.hidden && (!el.type || el.type !== 'hidden') && !el.closest('[hidden]')
+  return (
+    el.tabIndex >= 0 &&
+    !el.disabled &&
+    !el.hidden &&
+    (!el.type || el.type !== 'hidden') &&
+    !el.closest('[hidden]') &&
+    visible(el)
+  )
+}
+
+function visible(el): boolean {
+  return el.offsetWidth > 0 || el.offsetHeight > 0
 }
 
 function restrictTabBehavior(event: KeyboardEvent): void {