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@jameshfisher
Created October 13, 2018 17:37
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Demonstration that Strava Route Builder can't find routes at the prime meridian
// Open https://www.strava.com/routes/new, then copy/paste this code in the debug console.
// It should print results like this, showing that it can't find routes at the prime meridian:
//
// lng: -1.0, errCount: 0
// lng: -0.9, errCount: 0
// lng: -0.8, errCount: 1
// lng: -0.7, errCount: 0
// lng: -0.6, errCount: 0
// lng: -0.5, errCount: 0
// lng: -0.4, errCount: 0
// lng: -0.3, errCount: 0
// lng: -0.2, errCount: 0
// lng: -0.1, errCount: 0
// lng: 0 , errCount: 17 <----- HERE'S YOUR PROBLEM
// lng: 0.1, errCount: 0
// lng: 0.2, errCount: 0
// lng: 0.3, errCount: 0
// lng: 0.4, errCount: 0
// lng: 0.5, errCount: 0
// lng: 0.6, errCount: 0
// lng: 0.7, errCount: 0
// lng: 0.8, errCount: 0
// lng: 0.9, errCount: 1
// lng: 1.0, errCount: 0
function routeBetweenPoints(a, b) {
return fetch('https://www.strava.com/routemaster/route', {
method: "POST",
headers: {
'Content-Type': 'application/json; charset=utf-8',
'X-CSRF-Token': document.getElementsByName('csrf-token')[0].getAttribute('content')
},
body: JSON.stringify({
elements: [
{ element_type:1, waypoint: { point: a } },
{ element_type:1, waypoint: { point: b } }
],
preferences: {
popularity: 1,
elevation: 0,
route_type: 1,
straight_line: false
}
})
}).then(response => response.json());
}
function routeAtLatLng(lat, lng) {
return routeBetweenPoints(
{ lat: lat, lng: lng-0.01 },
{ lat: lat, lng: lng+0.01 }
);
}
function gen(from, to, by) {
const xs = [];
for (let x = from; x < to; x+=by) xs.push(x);
return xs;
}
function errsAtLng(lng) {
const lats = gen(44, 49, 0.2);
return Promise.all(lats.map(lat => routeAtLatLng(lat, lng)))
.then(routes => routes.filter(route => route.error === "Route request outside of routable paths"))
.then(errs => errs.length);
}
const lngs = gen(-1, 1, 0.1);
Promise.all(lngs.map(lng =>
errsAtLng(lng)
.then(errCount => { return { lng: lng, errCount: errCount }; })
)).then(results => console.log(results));
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