redirection not working

I'm trying to get this redirection working but it seems the irule is not working. When user enters https://test.domain.com it should redirect to https://test.domain.com/HELLO. Could someone advise what's wrong with the irule below ? I have a feeling that it's looping and looping.

I try "ends_with" or "starts_with" but doesn't seem to work. Upon removing the irule, it works if the browser is enter as "https://test.domain.com/HELLO";

when HTTP_REQUEST {
  if { [HTTP::uri] ends_with "/" } {
      HTTP::redirect "https://test.domain.com/HELLO"
 }
}