Function dataFromUrl

lib/internal/source_map/source_map_cache.js:237–255

* Resolves source map payload data from the source url and source map url. * If the source map url is a data url, the data is returned. * Otherwise the source map url is resolved to a file path and the file is read. * @param {string} sourceURL - url of the source file * @param {string} sourceMap

(sourceURL, sourceMappingURL)

 * @returns {object} deserialized source map JSON object
 */
function dataFromUrl(sourceURL, sourceMappingURL) {
  const url = URLParse(sourceMappingURL);

  if (url != null) {
    switch (url.protocol) {
      case 'data:':
        return sourceMapFromDataUrl(sourceURL, url.pathname);
      default:
        debug(`unknown protocol ${url.protocol}`);
        return null;
    }
  }

  const mapURL = URLParse(sourceMappingURL, sourceURL);
  if (mapURL === null) {
    return null;
  }
  return sourceMapFromFile(mapURL);
}

// Cache the length of each line in the file that a source map was extracted
// from. This allows translation from byte offset V8 coverage reports,