Two selectors maps are available, one on the core side
(/themes/_core/js/selectors.js) and another one inside the classic theme
That means that almost every selectors we use inside every JS files are inside these two files.
You can easily update these mapping because these 2 files send an event on dom ready :
selectorsInit for the core mapping file, and
themeSelectorsInit for the classic theme.
Also, if you place your file without these events, you need place it after the core/theme js bundle, it will work as it would with the event.
These selectors are mapped inside the
prestashop object. That means that if you attach a method which override the
prestashop.themeSelectors object, you’ll be able to change a lot of markup if you manage to override every selectors properly.