This shows an implementation of indy256's Convexhull.js for Leaflet L.latLng points. The function showConvexHull(latlngArray)

• takes an array of L.latLngs,
• shows them as markers on a map,
• calculates the convex hull with indy256's Convexhull.js,
• and draws the convex hull polygon on mymap.

var latlngArray = [];
latlngArray.push(L.latLng(50.5, 30.5))
latlngArray.push(L.latLng(51.5, 31.5))
latlngArray.push(L.latLng(51.5, 32.5))
latlngArray.push(L.latLng(50.7, 30.7))
latlngArray.push(L.latLng(50.8, 30.6))
latlngArray.push(L.latLng(51.5, 33.5))
latlngArray.push(L.latLng(53, 32.3))
latlngArray.push(L.latLng(51.7, 30.2))
    
    
function showConvexHull(latlngArray) {  
    
    latlngArray.forEach(function(element) { L.marker(element).addTo(mymap)});
    var points = latlngArray.map(function (element) {
        return {
            x: element.lat,
            y: element.lng
            }
        }
    )
    var convexHullPoints = convexHull(points);
    var leafletHull = convexHullPoints.map(function (element) {return ([element.x,element.y])})
    var convexHullPolygon = L.polygon(leafletHull).addTo(mymap);
    
    var bounds = convexHullPolygon.getBounds();
    mymap.fitBounds(bounds);

}