// current                                                                                                                                                                                                         
const DOWN_EVENTS = new Set(['mousedown', 'touchstart']);                                                                                                                                                          
                                                                                                                                                                                                                   
// should be                                                                                                                                                                                                       
const DOWN_EVENTS = new Set(['mousedown', 'onmousedown', 'pointerdown', 'onpointerdown']);                                                                                                                         
                                                                                                                                                                                                                   
Missing {{action}} modifier handling. The original detects <div {{action this.handler on="mousedown"}}> via the on hash pair. This PR only handles {{on}} modifiers and HTML attributes. Add an {{action}} check:  
                                                                                                                                                                                                                   
// inside the modifier loop:                                                                                                                                                                                       
if (modifier.path.original === 'action') {
  const onPair = modifier.hash?.pairs?.find(p => p.key === 'on');
  if (onPair && DOWN_EVENTS.has(onPair.value.value?.toLowerCase())) {                                                                                                                                              
    context.report({ node: modifier, messageId: 'unexpected' });                                                                                                                                                   
  }                                                                                                                                                                                                                
}