Function maybeCacheSourceMap

lib/internal/source_map/source_map_cache.js:157–200

* Caches the source map, with the given filename, moduleInstance, sourceURL and sourceMapURL. * This function does not automatically extract the source map from the content. The caller should either * extract the source map from the content via V8 API or use extractSourceURLMagicComment ex

(filename, content, moduleInstance, isGeneratedSource, sourceURL, sourceMapURL)

 * @param {string | undefined} sourceMapURL - the source map url
 */
function maybeCacheSourceMap(filename, content, moduleInstance, isGeneratedSource, sourceURL, sourceMapURL) {
  const support = getSourceMapsSupport();
  if (!(process.env.NODE_V8_COVERAGE || support.enabled)) return;
  const { normalizeReferrerURL } = require('internal/modules/helpers');
  filename = normalizeReferrerURL(filename);
  if (filename === undefined) {
    // This is most likely an invalid filename in sourceURL of [eval]-wrapper.
    return;
  }
  if (!support.nodeModules && isUnderNodeModules(filename)) {
    // Skip file under node_modules if not enabled.
    return;
  }

  // Bail out when there is no source map url.
  if (typeof sourceMapURL !== 'string') {
    return;
  }

  // Normalize the sourceURL to a file URL if it is a path.
  sourceURL = normalizeReferrerURL(sourceURL);

  const data = dataFromUrl(filename, sourceMapURL);
  // `data` could be null if the source map is invalid.
  // In this case, create a cache entry with null data with source url for test coverage.

  const entry = {
    __proto__: null,
    lineLengths: lineLengths(content),
    data,
    // Save the source map url if it is not a data url.
    sourceMapURL: data ? null : sourceMapURL,
    sourceURL,
  };

  if (isGeneratedSource) {
    generatedSourceMapCache.set(filename, entry);
    return;
  }
  // If it is not a generated source, we assume we are in a "cjs/esm"
  // context.
  const keys = sourceURL ? [filename, sourceURL] : [filename];
  getModuleSourceMapCache().set(keys, entry, moduleInstance);
}

/**
 * Caches the source map if it is present in the eval'd source.