source-map-js

Generating a source map

This feature allows you to generate a source map that describes how the code has been transformed. The code sample is a JSON representation of a source map.

{"version":3,"file":"min.js","names":["bar","baz","n"],"sources":["one.js","two.js"],"sourceRoot":"http://example.com/www/js/","mappings":"CAAC,IAAI,IAAM,SAAUA,GAClB,OAAOC,MAAM,KACb,IAAI,IAAM,SAAUE,GAClB,OAAOA"}

Consuming a source map

This feature allows you to consume a source map to retrieve the original position of a piece of code. The code sample shows how to use the SourceMapConsumer to get the original position of a code snippet.

const sourceMap = require('source-map-js');
const consumer = new sourceMap.SourceMapConsumer('{"version":3,"sources":["foo.js"],"names":["bar"],"mappings":"AAAA","file":"foo.js"}');
consumer.then(function(consumer) {
  console.log(consumer.originalPositionFor({line: 1, column: 1}));
});

Creating a source map generator

This feature allows you to create a source map generator which can be used to add mappings. The code sample demonstrates how to instantiate a SourceMapGenerator and add a mapping to it.

const sourceMap = require('source-map-js');
const generator = new sourceMap.SourceMapGenerator({
  file: 'min.js',
  sourceRoot: 'http://example.com/www/js/'
});
generator.addMapping({
  generated: { line: 1, column: 0 },
  original: { line: 1, column: 0 },
  source: 'one.js'
});
console.log(generator.toString());