index.js

#!/usr/bin/env node
'use strict';

var opts = require("nomnom").parse();
var fs = require('fs');
var transformJson = require('./transform-json');

if(!opts.input) {
  return console.log('--input has to be specified');
}
else if(!opts.output) {
  return console.log('--output has to be specified');
}
else if(!opts.transform) {
  return console.log('--transform has to be specified');
}
else {
  var inputFile = opts.input;
  var transformFile = opts.transform;
  var outputFile = opts.output;
  fs.readFile(inputFile, 'utf8', function (err,input) {
    if (err) {
      return console.log(err);
    }
    // input is there
    var inputJSON = JSON.parse(input);

    fs.readFile(transformFile, 'utf8', function (err,transform) {
      if (err) {
        return console.log(err);
      }
      // transform is there
      var templateJSON = JSON.parse(transform);
      var output = transformJson(inputJSON, templateJSON);

      fs.writeFile(outputFile, JSON.stringify(output, null, 2), function(err) {
        if(err) {
            console.log(err);
        } else {
            console.log("File " + outputFile + " successfully saved.");
        }
      });

    });

  });
}