richardvasquez / h3netold Goto Github PK

I was able to get this project to build in Visual Studio 2017, but only after upgrading the target framework. Didn't want to issue a pull request with such a big framework change, but after noticing that conversions between H3 and latitude/longitude were incorrect and that geo boundaries were not being generated correctly, I wrote this unit test for these conversions using the res0#ic.txt files in the input directory:

public static string[] ICFileNameStrings() => new [] { "res00ic.txt", "res01ic.txt", "res02ic.txt", "res03ic.txt", "res04ic.txt" };

    [Test, Sequential]
    public async Task Conversions_H3Index_GeoCoord([ValueSource("ICFileNameStrings")] string filename)
    {
        for (int i = 0; i <= 4; i++)
        {
            var fileName = $"res0{i}ic.txt";
            var path = Path.Combine(TestContext.CurrentContext.TestDirectory, "input", fileName);

            using (var sr = new StreamReader(path))
            {
                while (!sr.EndOfStream)
                {
                    var line = await sr.ReadLineAsync();
                    var match = Regex.Match(line, 
                        @"(?<h3>\w+)\s(?<lat>[-+]?([0-9]*\.[0-9]+|[0-9]+))\s(?<lon>[-+]?([0-9]*\.[0-9]+|[0-9]+))");

                    var h3str = match.Groups["h3"].Value;
                    var lat = double.Parse(match.Groups["lat"].Value);
                    var lon = double.Parse(match.Groups["lon"].Value);

                    var h3index = new H3Index(ulong.Parse(h3str, NumberStyles.HexNumber));

                    var coord = new GeoCoord(lat, lon);

                    assertExpected(h3index, ref coord);
                }
            }
        }
    }`

I was testing H3.Net and wanted to cross check it against Javascript version of the api at 3.2.0. I realized that the H3Index generated by .Net version and JS version differs even though they both are returned as valid index.

.Net code
GeoCoord gc = new GeoCoord(27.700769, 85.300140);
var index = Api.GeoToH3(gc, 7);
Console.WriteLine(index);
Console.WriteLine(Api.H3IsValid(index));

Result:
873F512E5FFFFFF
1

JavaScript code: (npm install [email protected])
const h3 = require("h3-js");
const h3Index = h3.geoToH3(27.700769, 85.300140, 7);
console.log(h3Index);
console.log(h3.h3IsValid(h3Index));

Result:
873c02992ffffff
true

Note: JS will produce same index for newer version of H3.