Generate source-maps from index mappings

Usage no npm install needed!

<script type="module">
  import sourceMapIndexGenerator from '';



Generate source-maps from index mappings.

Getting Started

Install the module with: npm install source-map-index-generator

// Load in SourceMapIndexGenerator
var SourceMapIndexGenerator = require('source-map-index-generator');

// Data output by node-jsmin2
var input = [
      '// First line comment',
      'var test = {',
      '  a: "b"',
    output = 'var test={a:"b"};',
    srcFile = 'input.js',
    coordmap = {"22":0,"23":1,"24":2,"25":3,"26":4,"27":5,"28":6,"29":7,"31":8,"33":9,"37":10,"38":11,"40":12,"41":13,"42":14,"44":15,"45":16};

// Generate source map via SourceMapIndexGenerator
var generator = new SourceMapIndexGenerator(generatorProps);

// Add the index coordinate mapping
  src: srcFile,
  input: input,
  output: output,
  map: coordmap

// Collect our source-map
generator.toString(); // {"version":3,"file":"min.js","sources":["input.js"],"names":[],"mappings":"AACA,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAC,CAAE,CAAE,CACT,CAAC,CAAE,CAAC,CAAC,CACP,CAAC"}


This module returns a constructor for SourceMapIndexGenerator.

new SourceMapIndexGenerator(startOfSourceMap)

To create a new one, you must pass an object with the following properties:

  • file: The filename of the generated source that this source map is associated with.

  • sourceRoot: An optional root for all relative URLs in this source map.


Add code with an index based mapping to the file collection.

The mapping object should have the following properties:

  • src: Filepath to original src.

  • input: Unminified JavaScript.

  • output: Minified JavaScript.

  • map: Map of character index to character index (number -> number)

  • lineOffset: An optional line offset to add to mappings.


In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using grunt.


Copyright (c) 2013 Todd Wolfson Licensed under the MIT license.