const currentPoint = along(animData.line, stepValue, { units: 'kilometers' })

function along(line, distance, options) {
    if (options === void 0) { options = {}; }
    // Get Coords
    var geom = invariant_1.getGeom(line);
    var coords = geom.coordinates;
    var travelled = 0;
    for (var i = 0; i < coords.length; i++) {
        if (distance >= travelled && i === coords.length - 1) {
            break;
        }
        else if (travelled >= distance) {
            var overshot = distance - travelled;
            if (!overshot) {
                return helpers_1.point(coords[i]);
            }
            else {
                // error happens here. 
                // "coords[i - 1]" is undefined
                // "bearing" function throws an error because "coords[i - 1]" is undefined
                var direction = bearing_1.default(coords[i], coords[i - 1]) - 180;
                var interpolated = destination_1.default(coords[i], overshot, direction, options);
                return interpolated;
            }
        }
        else {
            travelled += distance_1.default(coords[i], coords[i + 1], options);
        }
    }
    return helpers_1.point(coords[coords.length - 1]);
}