node

 var parseFile = require("./jsxmlparser.js");

// ReferenceError: mypath is not defined
//    at Object.<anonymous> (C:\Users\Aquazi\Desktop\Traducee\jsxmlparser.js:4:17)
//
//    at Module._compile (module.js:624:30)
//  at Object.Module._extensions..js (module.js:635:10)
//  at Module.load (module.js:545:32)
//  at tryModuleLoad (module.js:508:12)
//  at Function.Module._load (module.js:500:3)
//  at Module.require (module.js:568:17)
//  at require (internal/module.js:11:18)
//  at repl:1:17
//  at ContextifyScript.Script.runInThisContext (vm.js:50:33)

parsefile.js

var fs = require("fs");
var path = require("path");

module.exports=(mypath);

var inputFile = fs.readFileSync(mypath, "utf8");

var cheerio = require("cheerio");

var $ = cheerio.load(inputFile, {xmlMode:true});

// defines the selector
var relationship_number = $("Relationship").filter("[Id]").length;

// Initialize an empty object
var relationship_object = {};

// loops over the relationship xml in order to find the relationship Id and the target
// and adds the value to the relationship_object
for (i=0; i < relationship_number; i++){
    relationship_object[$("Relationship").filter("[Id]")[i].attribs.Id] = $("Relationship").filter("[Id]")[i].attribs.Target;
}

// gets a confirmation in console of correct parsing
if(Object.keys(relationship_object).length===relationship_number){
    console.log("Relationships parsed successfully")
}

relationship_json = JSON.stringify(relationship_object);

console.log(relationship_json);