sourcemap

var fs        = require('fs'),
    path      = require('path'),
    sourceMap = require('source-map');

var line = process.argv[2];
var column = process.argv[3];
var file = process.argv[4];
// file output by Webpack, Uglify, etc.
var GENERATED_FILE = path.join('.', file);

// line and column located in your generated file (e.g. source of your error
// from your minified file)
var GENERATED_LINE_AND_COLUMN = {line: line, column: column};

var rawSourceMap = fs.readFileSync(GENERATED_FILE).toString();
var smc = new sourceMap.SourceMapConsumer(rawSourceMap);

var pos = smc.originalPositionFor(GENERATED_LINE_AND_COLUMN);

// should see something like:
// { source: 'original.js', line: 57, column: 9, name: 'myfunc' }
console.log(pos);