async function loader()

in fusion-cli/build/loaders/babel-loader.js [38:90]

• 41 lines of code
• 6 McCabe index (conditional complexity)

async function loader(
  source,
  inputSourceMap,
  discoveryState /*: TranslationsDiscoveryContext*/
) {
  const filename = this.resourcePath;
  let loaderOptions = loaderUtils.getOptions(this);
  const cacheKey = crypto
    // non-cryptographic purposes
    // md4 is the fastest built-in algorithm
    .createHash('md4')
    // Changing any of the following values should yield a new cache key,
    // thus our hash should take into account them all
    .update(source)
    .update(filename) // Analysis/transforms might depend on filenames
    .update(JSON.stringify(loaderOptions))
    .update(babel.version)
    .update(fusionCLIVersion)
    .digest('hex');
  // Use worker farm if provided, otherwise require the worker code and execute it in the same thread
  const worker = this[workerKey] || require('./babel-worker.js');
  const cacheDir = path.join(
    loaderOptions.dir,
    'node_modules/.fusion_babel-cache'
  );

  const diskCache = getCache(cacheDir);

  const result = diskCache.exists(cacheKey)
    ? await diskCache.read(cacheKey)
    : await worker.runTransformation(
        source,
        inputSourceMap,
        cacheKey,
        filename,
        loaderOptions,
        this.rootContext,
        this.sourceMap
      );

  if (result) {
    const {code, map, metadata} = result;

    if (discoveryState && metadata.translationIds) {
      discoveryState.set(filename, new Set(metadata.translationIds));
    }

    return [code, map];
  }

  // If the file was ignored, pass through the original content.
  return [source, inputSourceMap];
}