Leaflet - Adding Popups to GeoJSON point used in Multiple Toggle Layers - leaflet

Question

Using Leaflet, I am creating a map that has multiple toggle layers. Each layer is a combination of a GeoJSON line string and multiple points, where each point is used in multiple layers (Bus routes and all stops on the route). This is what I have so far (leaving out all the messy GeoJSON data):
var busStops = L.geoJson([busStop1, busStop2, busStop3, busStop4]);
var busRoute10 = L.geoJson([route10, busStop1, busStop3]);
var busRoute12 = L.geoJson([route12, busStop2, busStop4]);
var baseLayers = {
"Route 12": busRoute10,
"Route 12": busRoute12,
"All Bus Stops": busStops,
};
L.control.layers(null, baseLayers, {collapsed: false}).setPosition ('topright').addTo(map);
Works great. My problem is in binding a popup to each of the points so when you click on a bus stop the name pops up. I am using:
function onEachFeature(feature, layer) {
// does this feature have a property named popupContent?
if (feature.properties && feature.properties.popupContent) {
layer.bindPopup(feature.properties.popupContent);
}}
but I am struggling to figure out where to call it. The only thing that has worked is:
var busStops = L.geoJson([busStop1, busStop2, busStop3, busStop4],{
onEachFeature: onEachFeature});
var busRoute10 = L.geoJson([route10, busStop1, busStop3],{
onEachFeature: onEachFeature});
var busRoute12 = L.geoJson([route12, busStop2, busStop4],{
onEachFeature: onEachFeature});
That seems really, really redundant. Is there a better way to do this?

Answer 1

Indeed you may bind multiple times the same popup content to bus stops that appear in several GeoJSON groups… but in fact you are building multiple times your bus stops.
If those are default markers with shadow, you should see the shadow stacking up (i.e. the background should become darker) when you display lines buses which share the same stop.
Now if you want to avoid these multiple bus stops copies, that would require a more complex approach, as removing a busLine1 which has busStop1 will remove the latter from map, even if it is also part of busLine2 which is still on map…
Demo: https://jsfiddle.net/3v7hd2vx/52/