Remove duplicate vertice on mongodb geojson collection

removeduplicatevertice.js

#!/usr/bin/env node
var path=require('path');
var fs = require('fs');
if(process.argv.length<3)
	throw new Error('You\'re not passing the geojson file');
var file=process.argv[2];

var gjFile=fs.statSync(file);
if(!gjFile.isFile())
	throw new Error('File not found');

var gjString=fs.readFileSync(file,'utf8');
var gJson=JSON.parse(gjString);


var removeDuplicate=function(point,coordinates,index){
		   var duplicate=false;
		   var duplicateIndex=null;
		   var lastIndex=coordinates.length-1;
           coordinates.forEach(function(el,j){
                                if(point[0]===el[0] && point[1]===el[1] && index!==j && j<lastIndex && j!==0){
                                   duplicate= true;
                                   duplicateIndex=j;
                                   console.log('found duplicate on '+duplicateIndex);
                                   console.log(point[0]+'='+el[0]+' && '+ point[1]+'='+el[1]);
                                }
                            });
           	

            if(duplicate===true){
                console.log('remove duplicate on '+duplicateIndex);
                coordinates.splice(duplicateIndex, 1);
            }
            //else
                //print('No duplicate');
            return coordinates;
        
};

gJson.features.forEach(function(feature,y){
    
    if(feature.geometry.type==='Polygon'){
            feature.geometry.coordinates[0].forEach(function(coordinates,i){
            	coordinates.forEach(function(point,index){
            		var coordinate=removeDuplicate(point,coordinates,index);
            		feature.geometry.coordinates[0]=coordinate;
            	});
            });
            
    }else if(feature.geometry.type==='MultiPolygon'){
            feature.geometry.coordinates.forEach(function(points,j){
                points.forEach(function(coordinates,i){

                    coordinates.forEach(function(point,index){
                        var coordinate=removeDuplicate(point,coordinates,index);
                        feature.geometry.coordinates[j][i]=coordinate;
                    });
                        
                       
                    
                });
                
             });
    }
    //update object
    gJson.features[y]=feature;
    
});
fs.writeFileSync(path.dirname(file)+'/clean-'+path.basename(file), JSON.stringify( gJson));

How to use it
node geojsontomongo.js <geojson-file>

Example
node geojsontomongo.js districts.geojson

@tyohan your script didn't work for me. It's only keeping one coordinate in geojson