var distance = require('turf-distance');
var point = require('turf-point');
var bearing = require('turf-bearing');
var destination = require('turf-destination');

/**
 * Takes a {@link LineString} feature and returns a {@link Point} feature at a specified distance along a line.
 *
 * @module turf/along
 * @param {LineString} line a LineString feature
 * @param {Number} distance distance along the line
 * @param {String} [units=miles] can be degrees, radians, miles, or kilometers
 * @return {Point} Point along the line at `distance` distance
 * @example
 * var line = turf.linestring([
 *  [-77.031669, 38.878605],
 *  [-77.029609, 38.881946],
 *  [-77.020339, 38.884084],
 *  [-77.025661, 38.885821],
 *  [-77.021884, 38.889563],
 *  [-77.019824, 38.892368]
 * ]);
 *
 * var along = turf.along(line, 1, 'miles');
 *
 * //=along
 */
module.exports = function (line, dist, units) {
  var coords;
  if(line.type === 'Feature') coords = line.geometry.coordinates;
  else if(line.type === 'LineString') coords = line.geometry.coordinates;
  else throw new Error('input must be a LineString Feature or Geometry');

  var travelled = 0;
  for(var i = 0; i < coords.length; i++) {
    if (dist >= travelled && i === coords.length - 1) break;
    else if(travelled >= dist) {
      var overshot = dist - travelled;
      if(!overshot) return point(coords[i]);
      else {
        var direction = bearing(point(coords[i]), point(coords[i-1])) - 180;
        var interpolated = destination(point(coords[i]), overshot, direction, units);
        return interpolated;
      }
    }
    else {
      travelled += distance(point(coords[i]), point(coords[i+1]), units);
    }
  }
  return point(coords[coords.length - 1]);
}

@@ -570,28 +570,136 @@
 e = 
-turf.lines
+%7B%0A *   %22type%22: %22Feature%22,%0A *   %22properties%22: %7B%7D,%0A *   %22geometry%22: %7B%0A *     %22type%22: %22LineS
 tring
-(
+%22,%0A *     %22coordinates%22: 
 %5B%0A *
+     
   %5B-
@@ -719,24 +719,29 @@
 .878605%5D,%0A *
+     
   %5B-77.02960
@@ -753,24 +753,29 @@
 .881946%5D,%0A *
+     
   %5B-77.02033
@@ -787,24 +787,29 @@
 .884084%5D,%0A *
+     
   %5B-77.02566
@@ -821,24 +821,29 @@
 .885821%5D,%0A *
+     
   %5B-77.02188
@@ -859,16 +859,21 @@
 563%5D,%0A *
+     
   %5B-77.0
@@ -893,18 +893,33 @@
 368%5D%0A * 
-%5D)
+    %5D%0A *   %7D%0A * %7D
 ;%0A *%0A * 
@@ -970,16 +970,109 @@
 %0A * 
-//=along
+var result = %7B%0A *   %22type%22: %22FeatureCollection%22,%0A *   %22features%22: %5Bline, along%5D%0A * %7D;%0A *%0A * //=result
 %0A */

Switch example to geojson primitives