makeIdentitySourceMap.js

function makeIdentitySourceMap(map, source, resourcePath) {
  source.split('\n').map(function (line, index) {
    map.addMapping({
      source: resourcePath,
      original: {
        line: index + 1,
        column: 0
      },
      generated: {
        line: index + 1,
        column: 0
      }
    });
  });
}