\version "2.22"

#(define (test_engraver ctx)
    (make-engraver
     (listeners
      ((tie-event engraver event)
       (format #t "Tie encountered at ~a.\n" (ly:context-current-moment ctx)))
      ((note-event engraver event)
       (for-each
        (lambda (art)
          (if (member 'tie-event (ly:event-property art 'class))
              (format #t "Tie encountered at ~a.\n" (ly:context-current-moment ctx))))
        (ly:event-property event 'articulations)))
       )))

\layout {
   \context {
     \Voice
     \consists #test_engraver
   }
}

{
   a4~
   <a~ g'> % this one is not seen by the engraver
   a~
   a
}