BRouter rd5 grid

grid.js

var fs  = require("fs"),
    topojson = require("topojson"),
    filesize = require('file-size');

// https://brouter.de/brouter/segments4/
var path = 'Index of _brouter_segments4_.html',
    gridSize = 5; // degrees

var entryList = [];

function readHtmlDirList(path) {
    var lines = fs.readFileSync(path).toString().split('\n');

    var i, matches, entry, 
        //<a href="E0_N10.rd5">E0_N10.rd5</a>                                         04-Feb-2021 01:03             7620723
        regex = /\s*<a href=\"(.*)\.rd5\".*<\/a>\s+(\S+)\s(\S+)\s+(\S+)\s*/;

    for (i = 0; i < lines.length; i++) {
        matches = lines[i].match(regex);
        if (matches) {
            entry = {
                name: matches[1],
                date: matches[2],
                //time: matches[3],
                size: filesize(+matches[4], { fixed: 0 }).human()
            };
            entryList.push(entry);
        }
    }
}

function toGeoJson() {
    var properties, matches, lat, lon
        features = [];

    function toPolygon(lat, lon) {
        var n = lat + gridSize,
            w = lon,
            s = lat,
            e = lon + gridSize;
        return [
            [ [w, n], [e, n], [e, s], [w, s], [w, n] ]
        ];
    }

    for (i = 0; i < entryList.length; i++) {
        properties = entryList[i];

        // W180_S85
        matches = properties.name.match(/(E|W)(\d*)_(N|S)(\d*)/);
        lon = parseInt(matches[2]) * ( matches[1] === 'E' ? 1 : -1 );
        lat = parseInt(matches[4]) * ( matches[3] === 'N' ? 1 : -1 );

        features.push({
            "type": "Feature",
            "geometry": {
                "type": "Polygon",
                "coordinates": toPolygon(lat, lon)
            },
            "properties": properties
        });
    }

    var geoJson = {
        "type": "FeatureCollection",
        "features": features
    };

    return geoJson;
}

function toTopoJson(geoJson) {
    return topojson.topology({
        collection: geoJson
    }, {
        'verbose': true,
        'quantization': false,
        'stitch-poles': false,
        'property-transform': function (feature) {
            return feature.properties;
        }
    });
}

function writeJson(path, obj) {
    fs.writeFile(path, JSON.stringify(obj), function(err) {
        if (err) {
            return console.error(err);
        }

        console.log('created file "' + path + '"');
    });
}

readHtmlDirList(path);

var geoJson = toGeoJson();
writeJson('grid.geojson', geoJson);

var topoJson = toTopoJson(geoJson);
writeJson('grid.topojson', topoJson);

package.json

{
  "name": "brouter-rd5-grid",
  "version": "0.1.0",
  "description": "Creates a 5° grid for the areas covered by BRouter rd5 routing data files as GeoJSON and TopoJSON",
  "dependencies": {
    "file-size": "^1.0.0",
    "topojson": "^1.6.19"
  },
  "license": "MIT"
}