A NodeJS script to extract the outer ring of GeoJSON polygons

extract-outer.js

var fs = require('fs')
  , _ = require('underscore')
  , file = require('./input.json')

_.each(file.features, function(feature, index){
  file.features[index].geometry.coordinates = [feature.geometry.coordinates[0]]
  console.log(index)
})

fs.writeFile('output.geojson', JSON.stringify(file), function(err){
  if(err) {
    console.log(err);
  } else {
    console.log("File created successfully!");
  }
})

Do you have a sample project which uses this script?