Function findSourceMap

lib/internal/source_map/source_map_cache.js:372–407

* Find a source map for a given actual source URL or path. * * This function may be invoked from user code or test runner, this must not throw * any exceptions. * @param {string} sourceURL - actual source URL or path * @returns {import('internal/source_map/source_map').SourceMap | undefined} a

(sourceURL)

 * @returns {import('internal/source_map/source_map').SourceMap | undefined} a source map or undefined if not found
 */
function findSourceMap(sourceURL) {
  if (typeof sourceURL !== 'string') {
    return undefined;
  }

  // No source maps for builtin modules.
  if (sourceURL.startsWith('node:')) {
    return undefined;
  }

  if (!getSourceMapsSupport().nodeModules && isUnderNodeModules(sourceURL)) {
    return undefined;
  }

  SourceMap ??= require('internal/source_map/source_map').SourceMap;
  try {
    if (RegExpPrototypeExec(kLeadingProtocol, sourceURL) === null) {
      // If the sourceURL is an invalid path, this will throw an error.
      sourceURL = pathToFileURL(sourceURL).href;
    }
    const entry = getModuleSourceMapCache().get(sourceURL) ?? generatedSourceMapCache.get(sourceURL);
    if (entry?.data == null) {
      return undefined;
    }

    let sourceMap = entry.sourceMap;
    if (sourceMap === undefined) {
      sourceMap = new SourceMap(entry.data, { lineLengths: entry.lineLengths });
      entry.sourceMap = sourceMap;
    }
    return sourceMap;
  } catch (err) {
    debug(err);
    return undefined;
  }
}

/**
 * Retrieve the original source code from the source map's `sources` list or disk.